Saf-T-Liner C2 School Bus. Driver’s Manual (2012)

Foreword

Introduction

Emissions and Fuel Efficiency

This manual provides information needed to operate

Compliance

and understand the vehicle and its components.

This vehicle must be regularly inspected and main-

More detailed information is contained in the Owner’s

tained as indicated in the Saf-T-Liner C2 Mainte-

Warranty Information Manual, the vehicle’s workshop

nance Manual, and in the Pre- and Post-Trip Inspec-

manual, and the vehicle’s maintenance manual.

tions and Maintenance chapter in this manual, in

Custom-built Thomas Built Buses are equipped with

order to continue satisfactory performance and en-

various chassis and body components. Not all of the

sure coverage of the vehicle under the manufactur-

information contained in this manual applies to every

er’s warranty. Many maintenance procedures ensure

vehicle. For details about components in your ve-

that the vehicle and engine continue to comply with

hicle, refer to the chassis specification pages in-

applicable emissions standards. Maintenance proce-

cluded in all new vehicles and to the vehicle specifi-

dures, using components engineered to comply with

cation decal, located inside the vehicle.

greenhouse gas emissions and fuel efficiency regula-

tions, may be performed by an authorized Daimler

For your reference, keep this manual in the vehicle

Trucks North America dealer, an independent outlet,

at all times.

or the vehicle owner or operator.

IMPORTANT: Descriptions and specifications in

The vehicle owner is responsible for determining the

this manual were in effect at the time of printing.

suitability of replacement components to maintain

Thomas Built Buses reserves the right to dis-

compliance with federal and local jurisdictional regu-

continue models and to change specifications or

lations. Components including, but not limited to, low-

design at any time without notice and without

rolling resistance tires are specifically designed and

incurring obligation. Descriptions and specifica-

manufactured to exacting standards for regulatory

tions contained in this publication provide no

fuel efficiency and greenhouse gas emissions compli-

ance. It is important that these components are al-

warranty, expressed or implied, and are subject

ways replaced with components that meet or exceed

to revisions and editions without notice.

the performance of the originally installed compo-

nents.

Environmental Concerns and

Recommendations

Customer Assistance Center

Whenever you see instructions in this manual to dis-

Having trouble finding service? Call the Customer

card materials, you should first attempt to reclaim

Assistance Center at 1-800-385-4357 or 1-800-FTL-

and recycle them. To preserve our environment, fol-

HELP. Call night or day, weekdays or weekends, for

low appropriate environmental rules and regulations

dealer referral, vehicle information, breakdown coor-

when disposing of materials.

dination, or Fleetpack assistance. Our people are

knowledgeable, professional, and committed to fol-

lowing through to help you keep your vehicle moving.

Event Data Recorder

This vehicle is equipped with one or more devices

Reporting Safety Defects

that record specific vehicle data. The type and

amount of data recorded varies depending on how

If you believe that your vehicle has a defect which

the vehicle is equipped (such as the brand of engine,

could cause a crash or could cause injury or

if an air bag is installed, or if the vehicle features a

death, you should immediately inform the National

collision avoidance system, etc.).

Highway Traffic Safety Administration (NHTSA) in

addition to notifying Daimler Trucks North America

LLC.

If NHTSA receives similar complaints, it may open

an investigation, and if it finds that a safety defect

exists in a group of vehicles, it may order a recall

STI-466-6 (3/14)

TBB85410323

Printed in U.S.A.

Foreword

and remedy campaign. However, NHTSA cannot

become involved in individual problems between

you, your dealer, or Daimler Trucks North America

LLC.

To contact NHTSA, you may call the Vehicle

Safety Hotline toll-free at 1-888-327-4236 (TTY:

1-800-424-9153); go to www.safercar.gov; or

write to: Administrator, NHTSA, 1200 New Jersey

Avenue, SE, Washington, DC 20590. You can also

obtain other information about motor vehicle safety

from www.safercar.gov.

Canadian customers who wish to report a safety-

related defect to Transport Canada, Defect Investi-

gations and Recalls, may telephone the toll-free

hotline 1-800-333-0510, or contact Transport

Canada by mail at: Transport Canada, ASFAD,

Place de Ville Tower C, 330 Sparks Street,

Ottawa, Ontario, Canada K1A 0N5.

For additional road safety information, please visit

roadsafety.

pany.

No part of this publication, in whole or part, may be translated, reproduced, stored in a retrieval system, or transmitted

in any form by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written per-

mission of Daimler Trucks North America LLC. For additional information, please contact Daimler Trucks North

America LLC, Service Systems and Documentation, P.O. Box 3849, Portland OR 97208-3849 U.S.A. or refer to

www.Daimler-TrucksNorthAmerica.comand www.ThomasBus.com.

Vehicle Identification

Vehicle Certification Plate and

HIGH POINT NORTH CAROLINA

MFD BY THOMAS BUILT BUSES INC.

Data Plate

DATE:

NOTE: Labels shown in this chapter are ex-

CHASSIS YARD NO.:

MODEL YEAR:

amples only. Actual label locations and specifi-

ENGINE:

SER NO:

cations may vary from vehicle to vehicle.

TRANS:

SER NO:

FRONT AXLE:

MOD NO:

INT AXLE:

MOD NO:

The certification plate is installed on the inside roof

REAR AXLE:

MOD NO:

liner above the driver’s window, or on the front bulk-

head. The certification plate indicates compliance

with all Federal Motor Vehicle Safety Standards

02/17/2004

f080136

(FMVSS) at the time of manufacture, gross axle

weight rating (GAWR) front and rear, gross vehicle

Fig. 1.2, Vehicle Data Plate

weight rating (GVWR), vehicle identification number

(VIN), vehicle type, body identification, and build

Buses purchased in the U.S. are marked as certified

date. See Fig. 1.1.

by means of an FMVSS certification label. See

Fig. 1.3. The tire and rim information are combined

into one label. This label is located in the driver area.

HIGH POINT NORTH CAROLINA

MFD BY THOMAS BUILT BUSES INC.

INC VEH MFD BY:

GVWR:

GAWR FRONT:

GAWR REAR:

THIS VEHICLE CONFORMS TO ALL APPLICABLE FEDERAL MOTOR VEHICLE

SAFETY STANDARDS IN EFFECT IN:

V.I.N.:

VEH. TYPE:

BODY ID:

11/14/2001

f080118

CHASSIS ID NO:

1. Date of Manufacture

2. Gross Vehicle Weight Rating

3. Gross Axle Weight Rating

01/16/2009

f080137

Fig. 1.3, Vehicle Certification Label

Fig. 1.1, Certification Plate

Chassis built without a cargo body that are intended

The data plate is installed on the inside roof liner

for service in the U.S. have an incomplete vehicle

above the driver’s window, or on the front bulkhead,

certification label attached by the final-stage manu-

and lists manufacturing information. See Fig. 1.2.

facturer. See Fig. 1.4. This label will be attached to

Whenever contacting parts, service, or warranty per-

the incomplete vehicle document included with the

sonnel regarding the vehicle, the following three

vehicle, and certifies that the vehicle conforms to all

numbers will be requested:

applicable FMVSS regulations in effect on the date of

• chassis identification number

completion.

• body identification number

• VIN

Federal Motor Vehicle Safety

11/14/2001

f080120

Standard Labels

Fig. 1.4, Incomplete Vehicle Certification Label

NOTE: Due to the variety of Federal Motor Ve-

hicle Safety Standard (FMVSS) certification re-

The tire and rim portion of the FMVSS certification

quirements, not all of the labels shown will apply

label certifies suitable tire and rim combinations that

to your vehicle.

can be installed on the vehicle, for the given gross

axle weight rating. Tires and rims installed on the

vehicle at the time of manufacture may have a higher

1.1

Vehicle Identification

load capacity than that certified by the tire and rim

label. If the tires and rims currently on the vehicle

have a lower load capacity than that shown on the

tire and rim label, then the tires and rims determine

the load limitations on each of the axles.

11/14/2001

f080119

Canadian Motor Vehicle Safety

1. Gross Weight Rating By Component in Axle System

Standard Labels

2. Gross Vehicle Weight Rating By Component in

Vehicle as a Whole

In Canada, buses are marked as certified by means

of a statement of compliance label with the Canadian

Fig. 1.6, Tire and Rim Information

National Safety Mark, which is located in the driver

area. See Fig. 1.5.

Vehicle Loading

The gross axle weight rating (GAWR) is the maxi-

mum weight the axle can carry. GAWR is the com-

bined capacity of the axle, brakes, tires, wheel equip-

ment, and suspension.

The gross vehicle weight rating (GVWR) is the maxi-

mum loaded weight of the vehicle. See Fig. 1.3.

NOTICE

10/10/2006

f080024

Never load the vehicle over the GVWR. Consider-

Fig. 1.5, Canadian National Safety Mark

able damage to the drivetrain may result if the

vehicle is over the GVWR.

If purchased for service in Canada, chassis built

without a body are marked as certified by a "State-

IMPORTANT: Passenger and cargo loads

ment of Compliance" label. See Fig. 1.3. This label

should be distributed proportionately over both

must be attached by the final-stage manufacturer to

the front and rear axles, and sides of the bus.

certify that the vehicle conforms to all applicable

Canada Motor Vehicle Safety Standard (CMVSS)

NOTE: Actual loads on the front and rear axles

regulations in effect on the date of completion..

can only be determined by weighing the vehicle

at highway weigh stations or similar facilities.

Tire and Rim Information

Overloading the vehicle is considered misuse

and will void the vehicle warranty.

The tire and rim label certifies suitable tire and rim

combinations that can be installed on the vehicle for

Emissions Labels

the given gross axle weight rating. Tires and rims

installed on the vehicle at the time of manufacture

EPA Noise Emission Control Label

may have a higher load capacity than that certified

by the tire and rim label. If the tires and rims cur-

A vehicle noise emission control label is attached

rently on the vehicle have a lower load capacity than

either to the left side of the dashboard or in the

that shown on the tire and rim label, then the tires

driver’s area. See Fig. 1.7.

and rims determine the load limitations on each of

It is the owner’s responsibility to maintain the vehicle

the axles.

so that it conforms to EPA regulations.

See Fig. 1.6 for U.S. and Canadian tire and rim

IMPORTANT: Certain incomplete vehicles may

labels.

be produced with incomplete noise control hard-

ware. Such vehicles will not have a vehicle

noise emission control information label. For

1.2

Vehicle Identification

VEHICLE NOISE EMISSION CONTROL INFORMATION

FREIGHTLINER CORPORATION

DATE OF MANUFACTURE

01/96

THIS VEHICLE CONFORMS TO U.S. EPA REGULATIONS FOR NOISE EMISSION

APPLICABLE TO MEDIUM AND HEAVY TRUCKS.

THE FOLLOWING ACTS OR THE CAUSING THEREOF BY ANY PERSON ARE PROHIBITED BY

THE NOISE CONTROL ACT OF 1972:

A. THE REMOVAL OR RENDERING INOPERATIVE, OTHER THAN FOR PURPOSES OF

MAINTENANCE, REPAIR, OR REPLACEMENT, OF ANY NOISE CONTROL DEVICE OR

ELEMENT OF DESIGN (LISTED IN THE OWNER’S MANUAL) INCORPORATED INTO THIS

VEHICLE IN COMPLIANCE WITH THE NOISE CONTROL ACT.

B. THE USE THIS VEHICLE AFTER SUCH DEVICE OR ELEMENT OF DESIGN HAS

BEEN REMOVED OR RENDERED INOPERATIVE.

24−00273−020

10/06/98

f080026

Fig. 1.7, Vehicle Noise Emission Control Label

03/02/2012

f080183

such vehicles, it is the final-stage manufactur-

er’s responsibility to complete the vehicle in

Fig.

1.8, Vehicle Emission Control Information Label

conformity to U.S. EPA regulations (40 CFR Part

205) and label it for compliance.

Aftertreatment System Indicators

Label

Engines and vehicles manufactured after December

31, 2006 and domiciled in the U.S. or Canada are

required to meet all EPA regulations effective as of

the vehicle build date, and are equipped with an

emission aftertreatment system (ATS). Vehicles do-

miciled outside of the U.S. and Canada may not

have aftertreatment equipment, depending upon local

statutory emissions guidelines. See Table 1.1.

There is a warning label (placement will vary by

bodybuilder) for important warning indicators in the

instrument cluster that pertain to the ATS.

It is a violation of U.S. federal law to alter exhaust

plumbing, ATS, or other components in any way that

would bring the engine/vehicle out of compliance with

certification requirements [Ref: 42 U.S.C. S7522(a)

(3)]. It is the owner’s responsibility to maintain the

vehicle so that it conforms to EPA regulations.

Vehicle Emission Control Information

Label

Model year 2013 and later vehicles meet additional

requirements as specified by federal greenhouse gas

and fuel efficiency regulations (GHG14). These ve-

hicles may be equipped with components, such as

low-rolling resistance tires, that increase fuel effi-

ciency and reduce GHG emissions.

A Vehicle Emission Control Information label is lo-

cated on the fan shroud. See Fig. 1.8. It is the own-

er’s responsibility to maintain the vehicle so that it

conforms to EPA and NHTSA regulations.

1.3

Vehicle Identification

Applicable Emissions System Based on Build Date and EPA Regulations

Build Date

Regulation: Emissions Components

EPA07 (reduce nitrogen oxides (NOx) emissions to 1.1 g/bhp-hr, and reduce

January 1, 2007-December 31,

particulate matter emissions to 0.01 g/bhp-hr): Aftertreatment device (ATD) containing

2009

a diesel particulate filter that traps soot and ash.*

EPA10 (reduce NOx emissions to 0.2 g/bhp-hr): EPA07-type ATD, with additional

January 1, 2010-December 31,

selective catalyst reduction (SCR) technology that utilizes diesel exhaust fluid (DEF)

2012

to convert NOx to nitrogen and water vapor.

GHG14: Aerodynamic and fuel efficiency components including low-rolling resistance

From March 5, 2012

tires specifically designed to meet regulatory fuel efficiency and greenhouse gas

emissions standards.

* Cummins, Detroit, and Mercedes-Benz ATD’s are also equipped with a diesel oxidation catalyst to break down pollutants.

Table 1.1, Applicable Emissions System Based on Build Date and EPA Regulations

1.4

Vehicle Access

ing and exiting the bus. Three-point contact

Assist Rails and Access Steps

means both feet and one hand, or both hands

and one foot.

WARNING

Stepwell Light

Wet or dirty shoe soles greatly increase the

chance of slipping or falling. If shoe soles are

A stepwell light is located on the bottom right-hand

wet or dirty, be especially careful when entering

side of the entry steps. See Fig. 2.2.

or exiting the bus. Always maintain three-point

contact with the bus access system while enter-

Entering the Bus

ing and exiting the bus. Three-point contact

Facing the steps, grasp the assist rail on either

means both feet and one hand, or both hands

side of the steps. See Fig. 2.2. Reach up as far

and one foot.

as is comfortable.

The two assist rails and three or four access steps

Place your right foot on the bottom step, and pull

are all part of the bus access system. Use these

yourself up.

when entering or exiting the bus to increase security

and comfort.

Place your left foot on the middle step.

Place your right foot on the top step.

Folding Steps

Folding steps mounted on both sides of the bus as-

sist in cleaning the windshield. The steps should be

kept clean and the pivot points should be kept lubri-

cated. See Fig. 2.1.

11/20/2003

f602148

12/05/2003

f602151

1. Folding Step

1. Steps

3. Stepwell Light

Fig. 2.1, Folding Step

2. Assist Rails

Fig. 2.2, Bus Entry and Exit

Entering and Exiting the Bus

Exiting the Bus

WARNING

1. Facing the steps, grasp the assist rail on either

side of the steps.

Wet or dirty shoe soles greatly increase the

chance of slipping or falling. If shoe soles are

2. Move your right foot on the first step.

wet or dirty, be especially careful when entering

or exiting the bus. Always maintain three-point

3. Place your left foot on the middle step.

contact with the bus access system while enter-

2.1

Vehicle Access

4. Step to the ground with your right foot first.

2. After entering the vehicle, activate the emer-

gency air release rocker switch located above

the door. See Fig. 2.4.

Front Door Opening and

3. Start the vehicle and allow it to warm up.

Closing

4. To close the door, move the paddle switch on the

Buses with Exterior Door Control

driver control panel to the DOOR CLOSED posi-

Front Door Opening

tion. See Fig. 2.3.

1. Open the front entrance door by turning the exte-

Front Door Closing

rior key switch to the open position and enter the

1. Shut down the engine.

vehicle.

2. Activate the emergency air release rocker switch

2. Start the vehicle and allow it to warm up.

located above the door.

3. To close the door, move the paddle switch on the

3. Manually push the door open and exit the ve-

driver control panel to the DOOR CLOSED posi-

hicle.

tion. See Fig. 2.3.

4. Close the door manually.

Battery Access

Battery Compartment

The battery compartment is located behind the

driver’s area, attached to the frame rail. To open the

battery access door, insert and turn the key, then pull

the access door open. Pull the pull-pin spring latches

out to slide the battery tray forward. See Fig. 2.5.

With the battery access door open, it is easy to get

access to the battery terminals for cleaning, charg-

ing, or emergency jump starting.

To close the battery access door, swing the door to

line up with the hole in the frame, then lock the bat-

05/29/2007

f720662

tery access door with the key.

Fig. 2.3, Door Open/Door Closed Paddle Switch

Battery Disconnect Switch, Optional

Front Door Closing

NOTICE

1. Shut down the engine.

The batteries must be disconnected if the vehicle

2. Move the paddle switch on the driver control

is not in use for a period exceeding two weeks,

panel to the DOOR OPEN position and exit the

or the vehicle may not start, and permanent bat-

bus.

tery damage could occur.

3. Turn the exterior key switch to the close position.

A battery disconnect switch, if so equipped, cuts off

all battery power to the vehicle. It is also used when-

Buses without Exterior Door Control

ever the vehicle is placed out of service for extended

Front Door Opening

periods to prevent battery discharge. The battery dis-

connect switch is located on the side of the battery

1. Manually open the door.

box. See Fig. 2.6.

2.2

Vehicle Access

If needed, you can also slow the rate of descent

with your hand.

3. Make sure the hood is flush with the cowl, then

secure the hood by engaging both hood hold-

down latches.

IMPORTANT: Make sure that both hold-down

latches are fully engaged before operating the

vehicle.

Emergency Roof Escape Hatch

NOTE: A warning buzzer should sound when

01/18/95

f600150a

any exit is open.

Fig. 2.6, Battery Disconnect Switch

The bus may have optional emergency roof escape

hatches located near the front and rear of the bus.

On buses equipped with an emergency roof escape

hatch, the opening instructions are clearly displayed

on the hatch cover. See Fig. 2.8.

10/24/2001

f880555

1. Fender

3. Latch Handle

2. Latch Hook

4. Half-Fender

Fig. 2.7, Hood Hold-Down Latch

NOTICE

12/05/2003

f602155

Do not let the hood free-fall to the fully open po-

sition. To do so could damage the hood or hood

Fig. 2.8, Emergency Roof Escape Hatch

straps.

Emergency Door

3. Standing in front of the hood, tilt the rear of the

hood upward until it reaches the over-center po-

Rear Emergency Door

sition (45-degrees from vertical). Then slowly

bring it to a stop.

The emergency door is located at the back of the

bus. To open the door, lift the release handle and

Closing the Hood

push the door out. Once the door is completely open,

it will automatically lock in the open position, allowing

1. Push the hood over center.

passengers to exit without holding the door open. To

close the door, push it back to release it from the

2. As the hood goes over center, the damper (if

equipped) automatically slows its rate of descent.

2.4

Vehicle Access

locked position. Close the door and lock it by push-

NOTE: Some states require that the operating

ing the release handle down. See Fig. 2.9.

instructions be located on the window glass.

Using the Main Entry/Exit Door in an

Vehicles Built Since January 9, 2008

Emergency

For vehicles built since January 9, 2008, the passen-

In an emergency, it may be necessary to use the red

ger emergency window exit is a vertical push-out

switch above the main door to open the door. Push

window. Lift up on the latch to open the window. A

down on the red switch to open the door, then push

buzzer will activate when an emergency window exit

the door open. See Fig. 2.4 and Fig. 2.10.

is open. See Fig. 2.11 and Fig. 2.12.

Emergency Window Exits

The bus has windows designated as emergency

exits. To open the windows in emergency situations,

follow the instructions that are displayed on the win-

dow frame.

NOTICE

TO RELEASE

OPENED

DOOR

FROM HELD POSTIION

− OPEN DOOR FULLY

− CLOSE DOOR

08/26/2008

f602145

Fig. 2.9, Emergency Door

2.5

Bus Features

Windows

Mirror Heat Switch, Optional

One or both side-view mirrors can be heated to keep

Driver’s Window

them clear of fog, frost, and ice.

To open the driver window, press the lock and slide

To heat the mirrors, press the upper part of the mir-

the window rearward. The window will only open

ror heat switch (MIRR HEAT) on the dash. See

half-way. See Fig. 3.1.

Fig. 3.2. When the mirror heat switch is on, an

amber indicator light illuminates inside the switch.

MIRR

HEAT

10/09/2001

f610524

To heat the mirrors, press up; press down to turn off the

heat.

Fig. 3.2, Mirror Heat Switch

The mirror heat switch is a smart switch (fully multi-

plexed).

Power Mirrors, Optional

The main outside mirrors, if heated, can be equipped

with an electrical remote control located on the

driver’s switch panel. See Fig. 3.3.

12/03/2003

f910514

1. Driver’s Window

Fig. 3.1, Driver’s Window

Passenger Windows

Passenger windows on the bus are opened by press-

ing the locks on the left-hand and right-hand side of

the window. There are three settings for the passen-

ger windows. The window can be opened to the one-

third, one-half, or full-open positions.

10/05/2001

f610523

Mirrors

To adjust the mirror position, press the keypad in the

Both driver-side mirrors and crossover mirrors are

direction you want the mirror to move.

standard on the bus.

1. Mirror Select Switch

2. Keypad

Fig. 3.3, Power Mirror Switch Pad

3.1

Bus Features

To select the mirrors on the left-hand side, press the

left side of the mirror select switch. To select the mir-

rors on the right-hand side, press the right side of the

mirror select switch.

The keypad has four arrow keys, pointing up, down,

left, and right. To adjust the mirror position, press the

keypad in the direction you want the mirror to move.

Seats

General Information

12/02/2003

f910512

1. Seat Slide

3. Isolator

WARNING

2. Lumbar Support

Keep hands, tools, and other objects away from

Fig. 3.4, Seat Slide and Isolator Lever

the scissor points under the seats. Failure to do

so could cause personal injury.

Unless otherwise noted, all seat adjustments should

be made while seated and before the engine is

started.

Due to the high degree of adjustability found in high-

back air suspension seats, it is possible to set the

seat back recline adjustment and the seat slide ad-

justment in such a combination that the seat back

will come into contact with the rear wall of the

driver’s compartment. It is the responsibility of the

driver to adjust the seat to prevent damage to the

seat and the driver’s compartment.

The following is a description of adjustments that are

available on one or more seats. Not all seats have all

of the adjustments listed below.

1. Seat Slide (fore-and-aft): When this adjustment is

made, the entire seat moves forward or back-

10/05/2001

f910483

ward on its track. See Fig. 3.4 for a description

A. Lumbar Support

B. Headrest Adjustment

of the seat slide and isolator lever.

2. Isolator: This feature (also referred to as back-

Fig. 3.5, Lumbar Support and Headrest Adjustment

slap isolator or Chugger-Snubber®) reduces the

4. Headrest: When this adjustment is made, the

amount of road shock by isolating the occupant

upper part of the backrest (back cushion)

from the motion of the vehicle, and allowing the

changes angle to provide head and upper back

upper seat to move in a simple pendulum mo-

support. See Fig. 3.5.

tion. Whenever the isolator is not desired, it can

be locked out. See Fig. 3.4.

5. Backrest Tilt: This adjustment pivots the backrest

forward or backward. See Fig. 3.6.

3. Lumbar Support: Lumbar support changes the

shape of the seat back to give more or less sup-

6. Seat Cushion Tilt: This adjustment raises or low-

port to the occupant’s lumbar (lower back) area.

ers the front and/or back of the seat (bottom)

This adjustment is either mechanical or air con-

cushion. This adjustment is easier to perform

trolled, depending on make and model of the

when all weight is removed from the seat. See

seat. See Fig. 3.5.

Fig. 3.6.

3.2

Bus Features

9. Damper: When you sit on the seat, a leveling

valve places you in the center of the ride zone.

When the damper is adjusted properly under nor-

mal driving conditions, the seat should not top or

bottom against the limits of the vertical travel.

10. Ride Firmness: A firmer ride gives a better feel

for the road but less protection against uneven-

ness in the road surface. A softer ride smooths

out the bumps.

Bench Seats

Bench seats are standard for passengers on all

buses. No adjustments are possible on the two-

person bench seat. See Fig. 3.8.

10/05/2001

f910484

A. Backrest Tilt

B. Seat Cushion Tilt

Fig. 3.6, Cushion Tilt Adjustments

7. Seat Tilt: When this adjustment is made, the seat

assembly, both backrest and seat cushion, tilts

forward or backward. See Fig. 3.6.

8. Ride Height Adjustment: The entire seat moves

up or down when adjusting the ride height. The

adjustment is either manual or air controlled, de-

pending on the make and model of the seat. See

Fig. 3.7.

12/02/2003

f910513

1. Non-adjustable Bench Seat

Fig. 3.8, Bench Seat

Track-Mounted Seats

10/05/2001

f910485

IMPORTANT: Track-mounted seats are the only

A. Ride Height

seats designed to be removed and reinstalled

on the school bus. Any other seats are non-

Fig. 3.7, Ride Height Adjustment

adjustable. For further information concerning

3.3

Bus Features

track-mounted seats, see Section 91.00, Sub-

Seat Cushion Tilt

ject 110 in the Saf-T-Liner C2 School Bus Work-

Rotate the seat cushion tilt knob to increase or de-

shop Manual.

crease seat cushion tilt.

Bostrom Seat

Backrest Tilt

Seat Slide Adjustment

To tilt the backrest, lean forward slightly to remove

pressure from the cushion and hold the backrest tilt

Move the seat slide and isolator lever to the left and

lever rearward. Lean backward slowly to the desired

hold it there to slide the seat forward or backward to

position and release the lever to lock the backrest in

the desired position. See Fig. 3.9.

place.

Ride Height and Damper Adjustment

To raise the seat, press the upper portion of the

height adjustment switch. To lower the seat, press

the lower portion of the switch.

Press the damper adjustment switch to adjust the

damper.

National 2000 Series Seat

Seat Slide Adjustment

Move the seat slide lever to the left and hold it there

to slide the seat forward or backward to the desired

position. Move the lever back to its original position

to lock the seat in place. See Fig. 3.10.

Isolator

12/08/2003

f910515

To use the isolator feature, turn the isolator handle to

1. Air Lumbar Support Control Valve (optional)

the horizontal position. Turn the isolator handle down

2. Damper Adjustment Switch

to lock out the isolator.

3. Height Adjustment Switch

4. Seat Slide and Isolator Lever

Lumbar Support

Fig. 3.9, Bostrom Seat

To adjust the lumbar support, use the lumbar support

switch on the side of the seat to give more or less

Isolator

support to your lower back.

To engage the isolator, put the seat slide and isolator

Backrest Tilt

lever in the center position. Lock out the isolator by

moving the lever to the right.

To tilt the backrest, turn the backrest tilt knob until

the desired position is reached.

Lumbar Support

To increase lumbar support, rotate the lumbar sup-

Seat Cushion Adjustment

port knob forward. To decrease lumbar support, ro-

To adjust the height of the front of the seat cushion,

tate the knob rearward.

lift the front cushion height adjustment handle, and

On seats equipped with air lumbar support, press the

pull forward or push back to the desired setting.

control valve upward to increase lumbar support.

To adjust the height of the rear of the seat cushion,

Press the control valve downward to decrease lum-

remove your weight from the seat and turn the rear

bar support.

cushion adjustment knob to one of three positions.

3.4

Bus Features

10/08/2001

f910487

1. Seat Slide Lever

2. Seat Cushion Tilt Adjustment

3. Ride Height Knob

4. Lumbar Support Lever

5. Backrest Lever

11/14/2000

f910445

Fig. 3.11, Sears Low Profile Seat

1. Backrest Tilt Knob

Lumbar Support

2. Lumbar Support Switch

3. Height Adjustment Switch

Move the three-position lumbar support lever upward

4. Seat Slide Lever

to increase lumbar support (firmer). Move the lever

5. Front Cushion Height Adjustment Handle

downward to decrease lumbar support (less firm).

6. Isolator Handle

7. Rear Cushion Adjustment Knob

NOTE: This three-position lever (see inset) does

Fig. 3.10, National 2000 Series Seat

not rotate a full 360 degrees.

For seats with air support, use the aft rocker switch

Ride Height Adjustment

on the control panel on the left-hand side of the seat.

To raise or lower the height of the seat, use the

Press up to make the seat firmer; press down to

height adjustment switch on the side of the seat.

make the seat less firm. See Fig. 3.13.

Seat Cushion Tilt

Sears Seat

Seat Slide Adjustment

To raise the seat cushion, lift upward on the front of

the seat cushion, and then push it rearwards. To

Push the seat slide (fore-and-aft adjustment) lever all

lower the seat cushion, pull forward on the front of

the way to the left and slide the seat forward or

the seat cushion, and then push downwards.

backward, as desired. Release the lever to lock the

seat in the desired position. See Fig. 3.11.

Backrest Adjustment

Isolator

To adjust the backrest, push downwards on the back-

rest lever just below the bottom of the backrest cush-

To engage the isolator (if installed), move the seat

ion. With the lever down, lean forward or backward

slide and isolator lever all the way to the right. To

to the desired position. Release the lever to lock the

lock out the isolator, move the isolator lever to the

backrest in place.

center position. See Fig. 3.12.

Ride Height Adjustment

Push the ride height knob inwards to inflate the air

cylinder, raising the height of the seat. Pull the ride

3.5

Bus Features

height knob outwards to deflate the air cylinder, low-

ering the height of the seat.

For seats with air support, use the forward rocker

switch on the control panel on the left-hand side of

the seat. Press up to raise the seat; press down to

lower the seat. See Fig. 3.13.

Ride Firmness Adjustment

For a softer ride, remove the snap ring and pin from

the shock absorber bracket (see inset). Relocate the

pin in the other set of holes in the bracket and se-

cure it with the snap ring.

Seat Belts and Tether Belts

General Information

Seat belt assemblies are designed to secure persons

in the vehicle to help reduce the chance of injury or

the amount of injury resulting from accidents or sud-

10/09/2001

f910486

den stops. For this reason, Daimler Trucks North

NOTE: Armrests are optional.

America LLC urges that the driver and all passen-

1. Lumbar Support Lever

gers, regardless of age or physical condition, use

2. Backrest Lever

seat belts when riding in the vehicle.

3. Ride Height Knob

4. Shock Absorber Bracket (ride firmness)

NOTE: Use passenger seat belts, if so

5. Pin (ride firmness)

equipped, when riding in the bus.

6. Snap Ring (ride firmness)

7. Seat Slide and Isolator Lever

IMPORTANT: Passenger seats may be con-

8. Seat Cushion Adjustment

structed either as seat belt-ready or without seat

belts. Do not add seat belts to seats that are not

Fig. 3.12, Sears Fleetmaster Seat (with isolator)

manufactured for seat belts.

WARNING

Always use the vehicle’s seat belt system when

operating the vehicle. Failure to do so can result

in severe personal injury or death.

Seat belt assemblies in Daimler Trucks North

America (DTNA) vehicles meet Federal Motor Ve-

hicle Safety Standard 209, "Type 1" and "Type 2" re-

quirements.

When transporting a child, always use a child re-

straint system or the vehicle seat belts as appropri-

10/08/2001

f910488

ate. To determine whether a child restraint system is

required, review and comply with applicable state

1. Ride Height Switch

and local laws. Any child restraint used must comply

2. Air Lumbar Support Switch

with Federal Motor Vehicle Safety Standard 213,

Fig. 3.13, Air Controls, Sears Seat

"Child Restraint Systems." When providing a child

restraint system, always carefully read and follow all

instructions pertaining to installation and usage for

3.6

Bus Features

the child. Make certain the child remains in the re-

Seat Belt Operation

straint system at all times when the vehicle is in mo-

tion.

Three-Point Seat Belt With Komfort Latch

In addition to seat belt assemblies, tether belts are

installed on suspension-type seats. Tether belts help

WARNING

secure the seat to the floor and are intended to re-

Wear three-point seat belts only as described

strain the seat and seat belt in case of an accident or

below. Three-point seat belts are designed to be

sudden stop.

worn by one person at a time. In case of an acci-

IMPORTANT: Seat belts have a finite life which

dent or sudden stop, personal injury or death

may be much shorter than the life of the vehicle.

could result from misuse.

Regular inspections and replacement as needed

Fasten the seat belts before driving. Fastening a

are the only assurance of adequate seat belt

three-point seat belt while driving creates a haz-

security over the life of the vehicle.

ard.

Seat Belt Inspection

1. Slowly pull the link end of the three-point seat

belt out of the retractor and pull it across your

lap (from outboard to inboard) far enough to en-

WARNING

gage the buckle. If the retractor locks too soon,

allow the belt to retract slightly, then slowly pull it

Inspect and maintain seat belts and tethers as

out again.

instructed below. Seat belts and tethers that were

damaged or stressed in an accident must be re-

2. Fasten the three-point seat belt by pushing the

placed, and their anchoring points must be

link into the buckle until it latches. Give the belt a

checked. When any part of a seat belt system

tug at the buckle. If the buckle unlatches, repeat

needs replacement, the entire seat belt must be

this step. If the problem continues, replace the

replaced, both the retractor and the buckle side.

three-point seat belt. See Fig. 3.14.

Do not attempt to modify the seat belt system;

doing so could change the effectiveness of the

system. Failure to replace damaged or stressed

seat belts or any modifications to the system

may result in personal injury or death.

Inspect the seat belts and tether belts (if so

equipped).

1. Check the web for fraying, cuts, or extreme wear,

especially near the buckle latch plate and in the

D-loop guide area.

2. Check the web for extreme dirt or dust, and for

severe fading from exposure to sunlight.

3. Check the buckle and latch for operation and for

wear or damage.

4. Check the Komfort Latch for function and cracks

01/18/95

f910004a

or other damage.

Fig. 3.14, Fastening the Three-Point Belt

5. Check the web retractor for function and dam-

age.

3. Position the shoulder strap diagonally across

6. Check the mounting bolts for tightness and

your chest with the adjustable D-loop bracket.

tighten any that are loose.

3.7

Bus Features

4. If desired, engage the Komfort Latch. See

4.3

While holding the belt slack, press the

Fig. 3.15 to adjust the shoulder harness and

Komfort Latch lever up, clamping the seat

Fig. 3.16 to lock the Komfort Latch.

belt webbing.

5. To unbuckle the three-point seat belt, push the

button on the buckle as shown in Fig. 3.17. If the

Komfort Latch was locked, release it by giving

the shoulder belt a quick tug. If you lean forward

against the shoulder belt, the Komfort Latch will

automatically release, and will need to be reset.

01/06/95

f910048a

1 Inch (2.5 cm) Maximum

Fig. 3.15, Adjusting Shoulder Harness Clearance

01/18/95

f910049a

Fig. 3.17, Releasing the Three-Point Seat Belt

NOTE: The Komfort Latch does not have to be

released in an emergency situation. The Kom-

fort Latch will release by itself under rough road

or other abnormal conditions. Make sure the

three-point seat belt is completely retracted

11/02/95

f910144

when it is not in use.

Fig. 3.16, Locking the Komfort Latch

Bus Amenities

4.1

Pull on the shoulder harness to lessen the

Storage

pressure of the strap on your shoulder

and chest.

Overhead Storage

4.2

Allow no more than 1-inch (2.5 cm) of

Buses are equipped with an overhead storage con-

slack between your chest and the shoul-

sole. See Fig. 3.18.

der harness.

NOTE: More slack can significantly reduce

Driver-Side Panel Storage

the seat belt’s effectiveness in an accident

A storage bin is located in the upper switch cabinet

or a sudden stop.

of the driver-side panel. See Fig. 3.19.

3.8

Instruments

The Saf-T-Liner C2 School Bus instrument clusters

Instrumentation Control Unit

have the capability to drive independent stand-alone

Figure 4.1 shows a typical set of instruments for ve-

gauges such as those installed on the auxiliary dash

hicles equipped with the Saf-T-Liner C2 School Bus

panel. Figure 4.2 shows a typical dash.

ICU3 instrument cluster.

Dash Message Center

NOTE: This instrument cluster is shown with the

U.S. speedometer, which shows miles per hour

The dash message center is the heart of the instru-

(mph) more prominently than kilometers per

ment cluster. It has two parts, a set of 27 warning

hour (km/h).

and indicator lights similar to those found on a con-

ventional lightbar, and a dash driver display screen.

The ICU3 instrument cluster can accept information

The driver display screen is a one-line by seven-

from the datalink and from various sensors installed

character liquid crystal display (LCD) that normally

on the vehicle, and deliver that information to elec-

shows odometer readings. Below this display is a

tronic gauges.

smaller one-line by three-character LCD that shows

voltmeter readings.

There can be up to eight gauges on the driver’s in-

strument panel (six electronic and two mechanical).

Only the air gauges operate mechanically.

07/08/2011

f611047

1. Engine Oil Pressure Gauge

6. Diesel Exhaust Fluid (DEF) Gauge

10. Speedometer

2. Dash Message Center

7. Primary Air Pressure Gauge

11. Tachometer

3. Headlight High-Beam Indicator

8. Mode/Reset Switch

12. Transmission Temperature Gauge

4. Dash Driver Display Screen

9. Secondary Air Pressure Gauge

13. Coolant Temperature Gauge

5. Fuel Level Gauge

Fig. 4.1, Gauge Layout (typical, U.S.), EPA10 and Newer Engines

4.1

Instruments

02/11/2004

f831616

NOTE: Instruments and controls, and their locations, may vary from those shown.

1. Left-Hand Window Outlet

4. Windshield Defrost Outlets

7. HVAC Cover

2. Instrumentation Control Unit

5. Right-Hand Dash Outlet

8. Climate Control Panel

(ICU3)

6. Right-Hand Window Outlet

9. Auxiliary Dash Panel

3. Left-Hand Dash Outlet

Fig. 4.2, Dash Panel Layout (typical)

The dash message center houses all of the standard

When the ignition is turned on, all the electronic

and optional warning and indicator lights. Warning

gauges complete a full sweep of their dials, the

messages and diagnostic fault codes will appear in

warning and indicator lights illuminate, and the

the driver display screen. For more information on

buzzer sounds for 3 seconds.

this system, see the heading "Ignition Sequence" in

NOTE: The air gauges do not sweep.

this chapter.

IMPORTANT: If any emergency exit is not

Ignition Sequence

closed a buzzer will sound continuously.

The dash message center goes through a prescribed

The following lights illuminate during the ignition se-

ignition sequence each time the ignition switch is

quence:

turned on. See Fig. 4.3 for the ignition sequence.

• Fasten Seat Belt Warning

4.2

Instruments

HEADLIGHTS ON

POWER ON

IGNITION ON

888888.8

TRIP MI KM HOURS

38.8 VOLTS

SERVICE

ENGINE

ICU PERFORMS SELF−TEST:

ODOMETER

ELECTRONIC GAUGE NEEDLES

SCREEN

SWEEP, WARNING/INDICATOR

LIGHTS COME ON, BUZZER SOUNDS

IF NO FAULTS

IF FAULT DETECTED

WERE DETECTED

ABS 136

123456.7

FAULT CODE

12.3 VOLTS

SCREEN

PARK BRAKE

RELEASED − MOVING

RELEASE PARK BRAKE

123456.7

12.3 VOLTS

10/24/2001

f040420b

Fig. 4.3, Ignition Sequence

• Low Battery Voltage Warning

• Fourth line: SERVICE ENGINE

• High Coolant Temperature Warning

During the second half of the self-test, the software

revision level is displayed.

• Low Engine Oil Pressure Warning

If there are no active faults, the driver display screen

• Low Air Pressure Warning

displays the odometer.

• Parking Brake On Indicator

If however, the instrument cluster has received active

fault codes from other devices, it displays them one

• All engine indicator/warning lights, including

after the other until the parking brake is released, or

Check Engine and Stop Engine

the ignition switch is turned off. Once the parking

• All ABS indicator/warning lights, including

brake is released, the dash message center displays

Wheel Spin, and Tractor ABS (if installed)

the odometer again.

NOTE: While the engine and ABS warning lights

NOTE: If active faults are present, take the ve-

illuminate during the ignition sequence, they are

hicle as soon as possible to an authorized

not controlled by the instrument cluster but by

Thomas Built Bus service facility.

their own system electronic control unit (ECU).

If the fault is mission critical, that is, if it is a serious

When the ignition switch is turned on, the ICU per-

problem that requires immediate attention, the stop

forms a self-test, looking for active faults. During the

engine system will activate. In most cases, the check

first half of the self-test, all segments of the display

engine light will also illuminate.

illuminate as follows:

Some examples of mission critical faults include:

• First line (odometer): 888888.8

• high coolant temperature

• Second line (units): TRIP MI KM HOURS

• low air pressure

• Third line (voltmeter): 38.8 VOLTS

4.3

Instruments

• low coolant level

• low engine oil pressure

PUSH−

NOTE: The check engine light does not illumi-

MODE

nate for a low air pressure fault.

The legend SERVICE ENGINE can appear on the

HOLD−

driver display screen as an active fault code. If this

RESET

legend appears, it means the trip miles (or hours)

have gone beyond the next required service interval,

09/25/99

f610340

as set by the vehicle operator.

IMPORTANT: If the legend SERVICE ENGINE

Fig. 4.4, Mode/Reset Switch

does appear on the driver display screen while

• Press the mode/reset switch a fourth time to

operating the vehicle, bring the vehicle to an

return to the odometer reading.

authorized Thomas Built Bus service facility

To reset trip miles and/or trip hours to zero, press the

when convenient.

mode/reset switch for 1 second or longer. To toggle

between MI (miles) or KM (kilometers), press the

Odometer

mode/reset switch while in the SELECT screen.

The odometer is set to display in either miles or kilo-

meters, depending on the primary scale of the

Warning and Indicator Lights

speedometer. The legend, either MI or KM, illumi-

nates between the odometer and the volts display

There can be up to 27 warning and indicator lights

when the engine is running or the headlights are

(telltales) installed in the dash message center. See

turned on.

Fig. 4.5. There are four rows of lights. Lights in-

stalled in the top row are optional and their positions

The odometer is a seven-digit display with a decimal

may vary. The lights in the bottom three rows are

point, until the vehicle has traveled 999,999.9 miles

installed in fixed positions on all vehicles. Most are

or kilometers (km). At one million miles (km), the

standard, but a few are optional.

odometer resets itself to 1,000,000, without the deci-

mal point, and can continue up to 9,999,999. The

NOTE: In the second, third, and fourth rows, if

odometer only displays significant figures (no leading

an optional telltale light is not installed, that po-

zeros).

sition is left blank.

Mode/Reset Switch

The instrument cluster has an emergency buzzer that

sounds when mission-critical conditions occur.

The mode/reset switch, shown in Fig. 4.4, is located

on the right side of the instrument cluster. The mode/

A description of the standard warning and indicator

reset switch is used to scroll through the displays on

lights are listed below.

the message display screen, and to reset the trip dis-

tance and trip hours values to zero.

Check Engine Indicator

When the odometer reading is displayed and the

The amber check engine indicator light (CHECK EN-

parking brake is applied:

GINE legend) illuminates when certain faults are de-

tected. If a critical engine condition exists (for ex-

• Press the mode/reset switch once and the trip

ample, low oil pressure or high coolant temperature),

distance will display.

the check engine light will illuminate to alert the

• Press the mode/reset switch a second time

driver to correct the condition as soon as possible. If

and the trip hours (engine hours) will display.

the condition gets worse, the stop engine light will il-

luminate.

• Press the mode/reset switch a third time and

the SELECT screen and the current units, MI

or KM, will display.

4.4

Instruments

The red stop engine warning light (STOP ENGINE

legend) illuminates to indicate that the protection sys-

tem available for the engine has been activated. On

OPT

some engines, the engine ECU will derate the en-

ABS

gine, allowing it to run, but at lower rpm and slower

CHECK

STOP

ABS

vehicle speed. The vehicle may be driven to a safe

location.

The engine ECU will derate the engine. The driver

must safely bring the vehicle to a stop on the side of

the road.

07/08/2011

f611066

NOTICE

1. Optional Indicator

2. Check Engine Indicator

Because operating the engine when the red stop

3. Stop Engine Warning

engine light is illuminated can lead to severe en-

4. Malfunction Indicator Lamp (MIL)

gine damage, the driver must move the vehicle to

5. ABS Indicator

a safe location as quickly as possible.

6. Transmission Overheat Indicator

7. Trailer ABS Indicator (not used)

To restart the engine turn the ignition switch to OFF,

8. Low Oil Pressure Warning

leave it there a few seconds, and turn the switch to

9. High Coolant Temperature Warning

START.

10. Fasten Seat Belt Warning

11. Parking Brake On Indicator

IMPORTANT: Do not attempt to restart the en-

12. Diesel Particulate Filter (DPF) Lamp

gine while the vehicle is moving. Bring the ve-

13. High Exhaust System Temperature (HEST) Lamp

hicle to a safe stop and restart the engine with

14. Left-Turn Signal Arrow

the vehicle stopped.

15. Low Battery Voltage Warning

16. Water In Fuel Indicator

17. Dash Driver Display Screen

Malfunction Indicator Lamp (MIL)

18. Headlight High-Beam Indicator

19. Cruise Control Indicator

Indicates an engine emissions-related fault, including,

20. Low Air Pressure Warning

but not limited to the aftertreatment system. See the

21. Right-Turn Signal Arrow

engine operation manual for details.

Fig. 4.5, ICU3 Warning and Indicator Lights, EPA10 and

ABS Indicator

Newer Engines

The amber ABS indicator light illuminates when there

NOTE: If the check engine light illuminates dur-

is a malfunction in the vehicle antilock brake system

ing vehicle operation, take the vehicle directly to

(ABS).

an authorized Thomas Built Bus service facility.

NOTE: For more information about this light and

the ABS system, see Chapter 10.

Stop Engine Warning

Transmission Overheat Indicator

WARNING

The amber transmission overheat indicator light

When the red STOP engine lamp illuminates,

(TRANS TEMP legend) illuminates when the tem-

most engines are programmed to shut down au-

perature of the transmission fluid goes above the

tomatically within 30 seconds. The driver must

preset level set by the transmission manufacturer.

immediately move the vehicle to a safe location

For more information, see the transmission manufac-

at the side of the road to prevent causing a haz-

turer’s manual provided with the vehicle.

ardous situation that could cause bodily injury,

property damage, or severe damage to the en-

gine.

4.5

Instruments

Blinking indicates that a stationary regeneration is

Low Oil Pressure Warning

required immediately. An engine derate and shut-

The red low oil pressure warning light (oil can icon)

down will occur. See the instructions in the engine

and emergency buzzer activate whenever the engine

manufacturer’s operator’s manual to perform a sta-

oil pressure goes below the preset minimum speci-

tionary regeneration.

fied by the engine manufacturer. See Table 4.1.

High Exhaust System Temperature

Oil Pressure Specifications*

(HEST) Lamp

At Idle Speed:

At Rated RPM:

Engine Model

psi (kPa)

A slow (10-second) flash, indicates a regeneration is

Cummins ISB

(69)

(207)

in progress, and the driver is not controlling the en-

gine idle speed.

* Oil pressure is given with the engine at operating temperature. With

the engine cold, oil pressure may be higher. Individual engines may vary

A solid illumination indicates potentially hazardous

from the listed pressures; observe and record pressures when the engine

is new to create a guide for checking engine condition.

exhaust temperatures at the outlet of the tail pipe if

Table 4.1, Oil Pressure Specifications

speed is below 5 mph (8 km/h). It does not signify

the need for service; it only alerts the vehicle opera-

tor of high exhaust temperatures. See the engine

High Coolant Temperature Warning

operation manual for details.

The red high coolant temperature warning light (ther-

Left-Turn Signal Arrow

mometer icon) and emergency buzzer activate when-

ever the coolant temperature goes above a preset

The green left-turn signal arrow flashes on and off

maximum specified by the engine manufacturer;

whenever the outside left-turn signal lights are flash-

225°F (107°C) for Cummins engines.

ing.

Both turn signal arrows flash when the hazard warn-

Fasten Seat Belts Warning

ing flasher is turned on.

The red fasten seat belts warning light (seat belt

icon) illuminates for 15 seconds after the ignition

Low Battery Voltage Warning

switch is turned on.

The red low battery charge warning light (battery

icon) illuminates when the battery voltage drops

Brake System Warning/Parking Brake

below 12 volts.

On Indicator

Water In Fuel Indicator

The red brake system warning/parking brake on indi-

cator light (BRAKE legend) activates whenever the

The amber water in fuel indicator illuminates when

parking brake is engaged.

the system detects water in the fuel tank.

If the vehicle is moving at a speed of 2 mph (3 km/h)

or more, the emergency buzzer will sound until the

NOTICE

parking brake is released.

Water in the fuel/water separator will appear as

NOTE: The BRAKE legend is required in the

beads. With the engine off, drain the separator

U.S. In Canada, the icon is required.

only enough to remove the water; about two tea-

spoons at a time. Do not drain the separator

Diesel Particulate Filter (DPF) Lamp

completely or it will be necessary to prime the

fuel system before the vehicle can be started

Solid illumination indicates a regeneration is required.

again.

Change to a more challenging duty cycle, such as

highway driving, to raise exhaust temperatures for at

least 20 minutes, or perform a stationary regenera-

tion. See the engine operation manual for details.

4.6

Instruments

• The coolant temperature rises above the pre-

WARNING

set level, which is 225°F (107°C).

Diesel fuel is flammable and can ignite if exposed

• The air pressure falls below the preset level,

to an open flame, intense heat, or other ignition

which is 65 psi (448 kPa).

source. Do not drain fuel near, or expose fuel

• The parking brake is set with the vehicle mov-

vapor to open flame or intense heat. Exposure to

ing at a speed greater than 2 mph (3 km/h).

open flame or intense heat could start a fire, pos-

sibly resulting in personal injury or property

Optional Indicator Lights

damage. When working on a fuel system, have a

fire extinguisher within easy reach.

The optional indicator lights that are available in-

clude: intake heater on indicator, low brake fluid

Drain any water collected in the fuel/water separator.

warning, low coolant warning, low fuel warning, auto-

matic transmission range inhibit warning, pall filter

Headlight High-Beam Indicator

indicator, differential lock warning, and wheel spin in-

The blue high-beam indicator light (sideways beam

dicator.

icon) illuminates when the headlight high beams are

on.

Air Filter Indicator

The optional amber air filter indicator light (AIR FIL-

Cruise Control Indicator

TER legend) illuminates when the air cleaner filter

element is clogged, restricting the intake air flow

A green indicator illuminates when the cruise control

below 25 inH₂O.

is activated.

If the air filter indicator light is steadily illuminated for

Low Air Pressure Warning

any period of time, check the air intake restriction

gauge. If needed, replace the air filter, and reset the

The red low air pressure warning light (pressure

air intake restriction gauge.

circle icon) and emergency buzzer activate when the

engine is turned on if air pressure in the primary or

IMPORTANT: Never attempt to clean the air fil-

secondary air reservoir is below 65 to 75 psi (448 to

ter.

517 kPa), and remain on until air pressure rises

above that level in both reservoirs.

Alternator No Charge Indicator

The warning light and buzzer also activate during

The optional amber alternator no charge indicator

operation whenever air pressure in the primary or

light (NO CHARGE legend) illuminates when the al-

secondary air reservoir falls below 65 to 75 psi (448

ternator is not charging properly.

to 517 kPa).

Check Transmission Indicator (diesel

Right-Turn Signal Arrow

engine only)

The green right-turn signal arrow flashes on and off

NOTE: Although it appears in the row of op-

whenever the outside right-turn signal lights are

tional indicator lights, the check transmission

flashing.

indicator is a standard indicator light.

Both turn signal arrows flash when the hazard warn-

The check transmission indicator light, shown in

ing flasher is turned on.

Fig. 4.6, notifies the driver of three things. The indi-

cator light has a solid illumination and any of the fol-

Emergency Buzzer

lowing items could be the cause for activating the

The emergency buzzer sounds during the ignition

light:

sequence and whenever one of the following condi-

• oil life monitor (determines when the oil needs

tions exists:

to be changed)

• The engine oil pressure falls below the preset

level shown in Table 4.1.

4.7

Instruments

• filter life monitor (determines when the filter[s]

Tachometer

need to be changed)

The tachometer indicates engine speed in revolutions

• transmission health monitor (determines when

per minute (rpm) and serves as a guide for shifting

clutch maintenance is required)

the transmission and keeping the engine in the ap-

When the check transmission indicator illuminates,

propriate rpm range. See Fig. 4.7.

refer to the Allison Operator’s Manual or contact cus-

tomer support at Allison Transmission to determine

Standard Instruments

the specific cause activating the indicator light.

Engine Oil Pressure Gauge

NOTICE

A sudden decrease or absence of oil pressure

may indicate mechanical failure. Bring the vehicle

to a safe stop and investigate the cause to pre-

vent further damage. Do not operate the engine

until the cause has been determined and cor-

rected.

02/28/2011

f611115

The engine oil pressure gauge is mission-critical.

See Fig. 4.8. If the engine oil pressure falls below

Fig. 4.6, Check Transmission Indicator, Diesel Engine

the preset levels shown in Table 4.1, first, the check

engine light will illuminate, and, if the condition does

Speedometer and Tachometer

not improve, the stop engine light will also illuminate

and the buzzer will sound. At this point, the engine

Speedometer

will derate or shut down, depending on the type of

engine protection system installed.

Three kinds of speedometer faces are available. The

U.S. version of the speedometer registers speed in

both miles per hour (mph) and kilometers per hour

(km/h), with mph in larger numbers. See Fig. 4.7.

PSI

110

100

130

OIL

RPM

km/h

X100

MPH

10/09/2001

f610528

Fig. 4.8, Engine Oil Pressure Gauge

10/09/2001

f610527

Coolant Temperature Gauge

1. Tachometer

2. Speedometer

Fig. 4.7, Speedometer and Tachometer (U.S. version)

NOTICE

The NAFTA version (not shown) of the speedometer

A sudden increase in coolant temperature may

face reverses this arrangement, with km/h in larger

indicate engine or cooling system failure. Bring

numbers. The metric-only version (not shown) shows

the vehicle to a safe stop and investigate the

km/h exclusively.

cause to prevent further damage. Do not operate

4.8

Instruments

the engine until the cause has been determined

and corrected.

During normal engine operation, the coolant tem-

perature gauge should read 175 to 195°F (79 to

1/2

ULTRA LOW SULFUR

91°C). See Fig. 4.9. If the temperature remains

DIESEL FUEL ONLY

below 160°F (71°C) or exceeds 225°F (107°C), in-

spect the cooling system to determine the cause.

See the vehicle workshop manual for troubleshooting

and repair procedures.

DEF

150

200

08/21/2009

f611045

F°

1. Diesel Fuel Level Indicator

2. DEF Level Indicator

3. Low DEF Warning Lamp (amber below 10% DEF)

100

250

4. Low Fuel Warning Lamp (amber at 1/8 tank of fuel)

WATER

Fig. 4.10, Fuel/DEF Gauge, EPA10

10/09/2001

f610565

Primary and Secondary Air Pressure

Fig. 4.9, Coolant Temperature Gauge

Gauges

The coolant temperature gauge is mission-critical.

See Fig. 4.9. If the coolant temperature rises above

WARNING

225°F (107°C), first, the check engine light will illumi-

If air pressure falls below minimum pressure, the

nate, and, if the condition does not improve, the stop

braking ability of the vehicle will be limited. Slow

engine light will also illuminate and the buzzer will

the vehicle down and bring it to a gradual stop.

sound. At this point, the engine will derate or shut

Do not attempt to move the vehicle until air pres-

down, depending on the type of engine protection

sure has risen above the minimum level. Moving

system installed.

a vehicle without adequate braking power could

cause an accident resulting in personal injury or

Fuel/Diesel Exhaust Fluid (DEF)

death.

Gauge

Air pressure gauges register the pressure in the pri-

For engines that are EPA10-compliant or newer, the

mary and secondary air systems. Normal pressure

fuel and DEF levels are measured in a dual purpose

with the engine running is 100 to 120 psi (690 to 827

fuel/DEF gauge. See Fig. 4.10.

kPa) in both systems. See Fig. 4.11.

The diesel fuel level is indicated at the top of the

Air pressure gauges are required on all vehicles with

gauge, with a low-level warning lamp that illuminates

air brakes. A low-air-pressure warning light and

when the diesel fuel level registers 1/8th of capacity.

buzzer, connected to both the primary and secondary

One fuel gauge is standard. If equipped with a sec-

systems, activate when air pressure in either system

ond (optional) fuel gauge, each fuel tank level is indi-

drops below a minimum pressure of 65 to 75 psi

cated on a separate gauge.

(448 to 517 kPa).

The DEF level is indicated in the lower portion of the

When the engine is started, the warning light and

gauge. There is a low DEF level warning lamp that

buzzer remain on until air pressure in both systems

illuminates when the DEF level reaches 10% of ca-

exceeds minimum pressure.

pacity. See Chapter 8 for details of the DEF gauge

functions.

4.9

Instruments

charging system and batteries checked at a repair

facility.

Optional Instruments

Optional instruments are not found on every vehicle.

They are stand-alones, not driven by the instrument

cluster, and are usually located on the auxiliary dash

panel. They are listed here in alphabetical order, to

make the information easier to find.

Air Intake Restriction Gauge

The air intake restriction gauge indicates the vacuum

on the engine side of the air cleaner. On standard

installations, it is mounted on the air intake duct in

the engine compartment. See Fig. 4.12. As an option

for easier viewing, the intake-air restriction indicator

can be mounted on the dash, usually on the right-

hand control panel.

10/22/2009

f610567

1. Primary Air Pressure Gauge

2. Secondary Air Pressure Gauge

Fig. 4.11, Air Pressure Gauges

Voltmeter

The voltmeter is a digital readout located on the bot-

tom line of the driver display screen whenever the

ignition switch is turned on.

It indicates the vehicle charging system voltage when

the engine is running and the battery voltage when

the engine is stopped. By monitoring the voltmeter,

the driver can be aware of potential charging system

problems and have them fixed before the batteries

discharge enough to create starting difficulties.

10/10/2001

f610568

The voltmeter will normally show approximately 13.7

to 14.1 volts when the engine is running. The voltage

Fig. 4.12, Air Intake Restriction Indicator

of a fully charged battery is 12.7 to 12.8 volts when

Air intake restriction vacuum is measured in inches

the engine is stopped. Battery voltage under 12.0

of water (inH₂O). For vehicles equipped with a

volts is considered a low battery, and a completely

graduated indicator or a restriction gauge on the

discharged battery will produce only about 11.0 volts.

dash, check the gauge with the engine off. If the yel-

The voltmeter will indicate lower voltage as the ve-

low signal stays locked in the red zone once the en-

hicle is being started or when electrical devices in

gine is shut down, or is at or above 25 inH₂O, the air

the vehicle are being used.

cleaner element needs to be replaced.

If the voltmeter shows an undercharged or over-

charged condition for an extended period, have the

NOTE: Rain or snow can wet the filter and

cause a temporarily higher than normal reading.

4.10

Instruments

Ammeter

An optional ammeter measures current flowing to

and from the battery. See Fig. 4.13. When the batter-

ies are being charged, the meter needle moves to

the plus side of the gauge; when the batteries are

being discharged, the needle moves to the minus

side. A consistent negative reading when the engine

is running indicates a possible problem with the

charging system.

10/10/2001

f610571

Fig. 4.14, Axle Oil Temperature Gauge

clock has a 24-hour alarm, with a three-minute

snooze feature. See Fig. 4.15.

10/10/2001

f610573

Fig. 4.13, Ammeter

Axle Oil Temperature Gauge, Rear

NOTICE

A sudden increase in oil temperature that is not

caused by a load increase may indicate mechani-

10/11/2001

f610576

cal failure. Bring the vehicle to a safe stop and

investigate the cause to prevent further damage.

Fig. 4.15, Digital Clock

Do not operate the vehicle until the cause has

been determined and corrected.

1. To set the time of day:

During normal operation, the optional rear axle oil

1.1

Push the Run/Set (lower) switch to the

temperature gauge should read between 160 and

right (TIME-SET position).

220°F (71 and 104°C) for Detroit^™ and Meritor^™ drive

NOTE: When the hour setting is for a time

axles. See Fig. 4.14.

between noon and midnight, the small letters

Under heavy loads, such as when climbing steep

PM will appear in the lower left corner of the

grades, temperatures up to a maximum of 250°F

display; no PM display indicates an AM set-

(121°C) are not unusual.

ting.

Digital Clock

1.2

Advance the hour setting to the correct

number by pushing and releasing the hour

The optional digital clock has black characters on a

button as many times as needed. Or if the

constantly backlighted green display, with a bright-

ness that automatically adjusts for day or night. The

4.11

Instruments

button is pressed and held in for longer

Engine Oil Temperature Gauge

than 2 seconds, the numbers will continue

to advance until the button is released.

NOTICE

1.3

Advance the minute setting by repeatedly

pushing, or pushing and holding the min-

A sudden increase in oil temperature that is not

ute button as needed.

caused by a load increase may indicate mechani-

cal failure. Bring the vehicle to a safe stop and

1.4

Push the Run/Set switch to the middle

investigate the cause to prevent further damage.

(RUN) position.

Do not operate the engine until the cause has

To set the alarm time:

been determined and corrected.

2.1

Push the Run/Set switch to the left

During normal operation, the optional engine oil tem-

(ALARM-SET position).

perature gauge should read between 180 to 225°F

(82 to 107°C) for Cummins ISB engines.

2.2

Set the alarm time by using the same pro-

cedure used to set the time of day; re-

NOTE: Under heavy loads, such as when climb-

member to set the hour for AM (no letters

ing steep grades, temperatures that exceed the

in the corner of the display), or PM as de-

normal oil temperature range for a short period

sired.

are not unusual. If the temperature returns to

2.3

Return the Run/Set switch to the middle

normal when the load decreases, there is no

(RUN) position; the readout will return to

problem. See Fig. 4.16.

the time-of-day setting.

Pyrometer

To operate the alarm:

An optional pyrometer can be installed on the ex-

3.1

With the alarm time set, push the alarm

haust pipe. A pyrometer registers the exhaust tem-

(upper) switch to the left. An alarm "wave"

perature near the turbocharger. See Fig. 4.17. Maxi-

symbol and the letters AL will appear in

mum exhaust temperature for the Cummins ISB

the upper left corner of the display when

engine is 1290°F (700°C).

the alarm is on.

Variations in engine load can cause exhaust tem-

3.2

When the displayed time of day coincides

peratures to vary. If the pyrometer reading shows

with the alarm time, the alarm will sound.

that exhaust temperature exceeds normal, reduce

If the SNOOZ button is not pushed or the

fuel to the engine until the exhaust temperature is

alarm switch is not moved, the alarm will

reduced. Shift to a lower gear if the engine is

automatically stop sounding after 1 minute

overloaded.

and will not sound again for 24 hours.

3.3

If desired, press the SNOOZ button while

the alarm is sounding to shut the alarm off

for 3 minutes. The alarm symbol will flash

in the display when the button is pushed

and will continue to flash until the alarm

switch is moved or the alarm has sounded

for one minute. The snooze procedure can

be done as many times as desired.

3.4

Move the alarm switch to the right when

you wish to shut off or cancel the alarm;

the alarm symbol will disappear.

10/10/2001

f610569

Fig. 4.16, Engine Oil Temperature Gauge

4.12

Instruments

Turbocharger Boost Pressure Gauge

A turbocharger boost pressure gauge measures the

pressure in the intake manifold, in excess of atmos-

pheric pressure, being created by the turbocharger.

See Fig. 4.19.

10/10/2001

f610570

Fig. 4.17, Pyrometer

Transmission Fluid Temperature

Gauge

10/10/2001

f610574

During normal operation, the transmission fluid tem-

perature gauge reading should not exceed 250°F

Fig. 4.19, Turbo Boost Pressure Gauge

(121°C). See Fig. 4.18.

200

275

125

350

TRANS

10/30/2001

f610600

Fig. 4.18, Transmission Fluid Temperature Gauge

NOTICE

A sudden increase in transmission fluid tempera-

ture that is not caused by a load increase may

indicate mechanical failure. Bring the vehicle to a

safe stop and investigate the cause to prevent

further damage. Do not operate the vehicle until

the cause has been determined and corrected.

NOTE: Under heavy loads, such as when climb-

ing steep grades, temperatures may climb

above those given here for limited periods.

4.13

Controls

• Rocker switches can be pressed up or down to

Ignition Switch and Key

perform a function. Certain rocker switches are

The ignition switch has four positions: ACCESSORY,

guarded to prevent them from being switched

OFF, ON, and START. See Fig. 5.1.

on or off accidentally.

When the panel lights are on, most switch legends

are backlit with a colored light, usually green. This

allows the driver to find the switch more easily in the

dark. When the switch is on, the switch icon is nor-

mally backlit with a colored light, usually amber.

Some switch icons are dead-fronted (not visible until

the switch is turned on). When turned on, some

switches are illuminated from within by a red or

amber light-emitting diode (LED).

Headlight/Parking Light Switch

The headlight/parking light switch is a paddle switch

located on the left-hand control panel above the

09/12/2001

f610509

cruise/RPM control switches. See Fig. 5.2. When the

Fig. 5.1, Ignition Switch Positions

paddle is lowered, the parking lights illuminate (the

front turn signals, the marker and identification lights,

In the OFF position, the key slot is vertical; the key

and the taillights). When the paddle is raised, the

can be inserted and removed only in this position.

low-beam headlights illuminate, along with all the

The following can be operated in the OFF position

parking lights. To turn off all lights, return the paddle

(regardless of whether the key is inserted): low beam

to the center position.

headlights, taillights, brake lights, road lights, clear-

ance lights, turn signals, hazard warning lights, horn,

CB radio, clock, and electric oil pan heater.

In the ACCESSORY position, the key is turned coun-

terclockwise. The radio (if so equipped), mirror heat,

air dryer, backup lights, and all of the components

that are operable in the OFF position are operable in

the ACCESSORY position.

All electrical systems are operable in the ON posi-

tion. The warning lights and the buzzer for low air

pressure and low oil pressure operate until minimum

pressures are built up.

10/15/2001

f610580

Turn the key fully clockwise to the START position to

Raise the paddle to illuminate the low-beam headlights.

start the engine. When the engine starts, release the

Lower the paddle to illuminate the parking lights.

key.

Fig. 5.2, Headlight/Parking Light Switch

Lighting Controls

NOTE: The front turn signal is the amber lens in

The lighting controls operate through switches lo-

each headlight unit. The low-beam headlight is

cated on the dash. Two types of dash switches are

the top clear lens in each headlight unit.

used:

When the headlights or parking lights are on, the

• Paddle switches have a single paddle located

panel lights also illuminate. An amber light in the

in the center of the switch. The paddle can be

switch backlights either the top icon (for headlights

raised or lowered to perform a function.

and parking lights) or the bottom icon (for parking

lights only).

5.1

Controls

Daytime Running Lights

Switching on the ignition and releasing the parking

brakes automatically activates the daytime running

lights, if so equipped. The daytime running lights will

operate until the parking brakes are applied or the

headlights are turned on.

NOTE: Daytime running lights are standard on

11/25/2003

f544369

all Canadian vehicles.

1. Phillips Screws

The daytime running lights illuminate at about two-

thirds of normal power.

Fig. 5.4, Dome Light

Panel Light Increase/Decrease Switch

Interior Dome Light Replacement

When the panel lights are on, they can be either

To replace the interior light(s) do the following. See

brightened or dimmed by using the INCR/DECR

Fig. 5.4.

rocker switch just below the headlight switch. See

1. Remove the two Phillips screws that attach the

Fig. 5.3. To brighten the panel lights, press the upper

lens.

part of the switch (at the "INCR+" legend). To dim the

panel lights, press the lower part of the switch (at the

2. Replace the bullet-type bulb and install the lens

"DECR-" legend).

on the lamp base using the removed screws.

When the panel lights are on, both legends are back-

lit in green.

Multifunction Turn Signal

Switch

The multifunction turn signal switch is attached to the

left-hand side of the steering column. This switch has

the following functions:

• turn signals

• windshield wipers and washers

• high-beam headlights

• hazard warning lights

See Fig. 5.5 for the multifunction switch and its com-

10/29/2001

f610598

ponent parts.

Fig. 5.3, Panel Light Increase/Decrease Switch

Turn Signal Lever

Footwell Light

The turn signal lever is mounted on the steering col-

umn. See Fig. 5.6. Moving the lever down activates

A footwell light is located near the steps of the bus to

the left turn signal lights; moving it up activates the

provide light in the step area.

right turn signal lights.

Interior Dome Lights

When a turn signal is activated, a green indicator

arrow flashes at the far left or far right of the instru-

Diffuse dome lights are installed on all buses. The

ment panel.

standard dome light has a clear lens and is installed

on the roof of the bus. See Fig. 5.4 for the rear

The lever automatically returns to the neutral position

dome light.

(self-cancels the switch) when the steering wheel

returns to the straight ahead position after a turn. To

5.2

Controls

The wipers are operated by a rotary switch in the

wiper control dial, which is on the end of the turn sig-

nal lever. See Fig. 5.7. There are five delay settings,

marked on the dial by lines of increasing length, and

two steady speed settings, LO and HI.

11/16/2001

f820386

Press down on the upper part of the rocker switch to

activate the warning lights.

1. Washer Button

2. Wiper Control Dial

3. Turn Signal Lever

10/29/2001

f820383

4. Hazard Warning Light Rocker Switch (red)

Rotate the control dial forward to turn the wipers on, or

5. Multifunction Switch Module

speed them up.

Fig. 5.5, Multifunction Turn Signal Switch

Rotate the control dial backward to slow the wipers down,

or turn them off.

1. Washer Button

2. OFF Position

3. Delay Positions

4. Wipers On, Low Speed

5. Wipers On, High Speed

Fig. 5.7, Wiper/Washer Controls

Rotating the control dial forward (in a counterclock-

wise direction) turns the wipers on. If they are al-

ready on, rotating the handle further forward in-

creases the speed of the wipers through the various

delay settings, and to the LO and HI settings.

Rotating the control dial in the opposite direction

10/17/2001

f820384

(clockwise) causes the wipers to slow down. Rotating

Move the lever down to activate the left turn signals.

the control dial clockwise as far as it will go (to the

Move the lever up to activate the right turn signals.

OFF setting) turns the wipers off.

Fig. 5.6, Turn Signal Controls

The washers are operated by a yellow button at the

very end of the turn signal lever. To operate the

cancel the signal manually, move the lever to the

washers, press the button in and hold it.

neutral position.

Headlight High Beams

Windshield Wiper/Washer Controls

Push the turn signal lever forward, towards the wind-

shield, to turn on the high-beam headlights. Pull the

NOTICE

turn signal lever back to its original position to turn

them off. See Fig. 5.8.

Do not move the wiper arms manually. Wiper

motor damage will occur if the arms are moved.

5.3

Controls

down on the lower part of the rocker switch (towards

the steering wheel).

Driver Switch Panel Controls

To the left of the driver is a switch panel. The panel

has a variety of switches and a light monitor panel.

The light monitor panel tells the driver when various

lights are operating on the bus. See Fig. 5.9 and

Fig. 5.10. The following list describes the function of

the various switches on the driver switch panel.

•

Video—Operates the video camera, if so

equipped.

10/17/2001

f820385

•

Defrost Fan—Operates the defrost fan.

Move the lever forward to turn on the high beams. Move

•

Strobe Light—Turns the strobe light on and off.

the lever back to its original position to turn them off.

Move the lever back toward the steering wheel to flash

•

Red Warning Lights—Operates the flashing

the high beams momentarily.

lights at the front and back of the bus.

1. Turn Signal Lever

2. Boot

•

Amber Warning Lights—Operates the flashing

lights at the front and back of the bus.

Fig. 5.8, Headlight High Beams

•

Amber Warning On/Off—Operates the amber

When the high beam headlights are on, a blue light

marker lights.

illuminates on the instrument panel between the ta-

chometer and speedometer. For vehicles built to op-

•

Dome Lights—Turns the six inside dome lights

erate in the United States, switching on the high

on and off.

beams will switch off the road lights.

•

Door Open/Door Closed—Opens and closes

NOTE: The ignition switch must be on for the

the main entry door; see Chapter 2 for operat-

high beams to work.

ing instructions.

With the headlight low beams on, pull the lever back-

•

Light Monitor Panel—Shows the driver what

ward, towards the steering wheel, to flash the high

lights are on.

beams momentarily.

•

Noise Suppression (not shown)—When acti-

The headlight low beams remain on continuously

vated, the noise suppression system will simul-

during high beam operation. If the low beam head-

taneously turn off all noise-producing accesso-

lights are turned off using the headlight switch, the

ries with one switch. Noise-producing

high beams turn off also.

accessories include heater blowers, air condi-

tioning, defroster fans, auxiliary fans, and the

Hazard Warning Lights

radio, if so equipped.

•

Passenger Advisory—The passenger advisory

The hazard warning light flasher is a red rocker

switch located on the top of the multifunction switch

activates the emergency exit buzzer when the

module. See Fig. 5.5. When the warning lights are

driver turns the ignition switch off. The driver

activated, all of the turn signal lights (front, side, and

must walk to the back of the bus and check

rear) and the two green indicator arrows on the in-

that all of the seats are empty. There are two

strument panel will blink on and off.

ways to deactivate the buzzer, depending on

how the bus was built: either press the reset

To activate the hazard warning lights, press down on

switch located at the rear driver-side of the

the upper part of the rocker switch (towards the

bus, or open the rear emergency exit door

dash). To deactivate the hazard warning lights, press

within 60 seconds.

5.4

Controls

If the 60-second time period elapses before the

• request regeneration

reset switch at the rear of the bus is pressed,

• default (automatic regeneration)

the horn will begin to pulse. To deactivate the

horn, the ignition must be turned ON and then

• inhibit regeneration

OFF. At this time, the 60-second timer starts

See the engine operation manual for details on op-

again and the driver must repeat the steps to

eration of the regen switch.

press the reset switch at the rear of the bus or

open the rear emergency exit door.

NOTE: Driver panel switches can be arranged

in any sequence.

11/26/2003

f610687

1. Video

4. Red Warning Lights

7. Dome Lights

2. Defrost Fan

5. Amber Warning Lights

8. Door Open/Door Closed

3. Strobe Light

6. Amber Warning On/Off

9. Light Monitor Panel

Fig. 5.9, Driver Switch Panel (typical)

Multiple options are available on the driver switch

Automatic Tire Chain Control

panel depending on individual school districts. These

options will be on the second and third rows of the

Automatic tire chains are optional. See Fig. 5.12 for

driver switch panel.

an example of the automatic tire chain switch. An

LED in the switch illuminates when the tire chains

are activated.

Aftertreatment System (ATS)

Regen Switch

Engaging/Disengaging the Tire

NOTE: Some alternative fueled vehicles are not

Chains

equipped with a regeneration (regen) switch.

IMPORTANT: The tire chains must be engaged

A regen switch, located on the dash, allows the

and disengaged while moving, and before slip-

driver to control three states. See Fig. 5.11. These

page occurs.

include:

5.5

Controls

mph (8 to 40 km/h). If the tire chains need to be

engaged from a standstill, spin the tires at 5 mph

(8km/h) before engaging the chains. This will

SCHOOL BUS

prevent the chains from becoming tangled. Do

not spin the tires too fast, as this will increase

FRONT

the time it takes to gain traction.

REAR

2. When the tire chains are no longer needed, they

must be disengaged when traveling between 5 to

30 mph (8 to 48 km/h).

3. When approaching an icy grade and the tire

chains have not been engaged, adjust speed to

25 mph (40 km/h) and engage the tire chains.

Then, slowly regain and maintain speed.

Use of the Tire Chains While They

11/26/2003

f610688

Are Engaged

Fig.

5.10, Light Monitor Panel

1. For maximum efficiency of the tire chains, main-

tain a minimum speed of 5 mph (8 km/h).

2. Do not exceed 30 mph (48 km/h) with the tire

chains engaged.

The LED in the automatic tire chain switch

flashes when vehicle speed reaches 35 mph (56

km/h) or more, notifying the driver to reduce

speed.

3. When climbing a hill with the tire chains, try to

maintain momentum. This will improve the perfor-

mance of the tire chains.

4. For the best results while moving, accelerate

06/19/2012

f611199

slowly. Spinning the wheels will result in a loss of

Fig.

5.11, Regen Switch

traction.

5. When using the tire chains in reverse, they will

work best at speeds above 5 to 8 mph (8 to 13

km/h).

6. The tire chains are not as effective when snow

depths exceed 6 to 8 inches (15 to 20 cm).

7. The vehicle can stop on the chains, and then

start moving again, provided the switch is still in

the engaged position.

Braking and Stopping

06/12/2012

f611197

1. When stopping on snowy or icy roads, engage

the chains before stopping to increase traction,

Fig.

5.12, Automatic Tire Chain Switch

and to increase traction when restarting.

1. The tire chains must be engaged from the dash

2. Avoid locking the brakes while braking under any

mounted switch when traveling between 5 to 25

conditions.

5.6

Controls

3. After stopping, start moving slowly to increase

traction. Do not spin the tires.

Horn Control

10°

A single electric horn is standard. Dual electric horns

are available as an option.

The button for the horn is located in the center of the

steering wheel. To sound the horn, press down on

the button. See Fig. 5.13.

10°

11/14/2001

f461923

9 o’Clock

3 o’Clock

Fig. 5.14, Steering Wheel Centered

To tilt the steering column, press down on the foot

pedal located below the steering wheel to release the

steering column lock. Adjust the column to the de-

sired position. Release the foot pedal to lock the

steering column in place. See Fig. 5.15.

10/17/2001

f461918

To sound the horn, press down on the horn button.

1. Horn Button

Fig. 5.13, Horn Control

Steering Controls

WARNING

Make sure that the steering column is locked be-

fore driving the vehicle. Never tilt or telescope

the steering wheel while driving the vehicle.

Doing so could cause loss of vehicle control,

personal injury, and property damage.

When there is no load on the vehicle and the front

tires are pointed straight ahead, the steering wheel

spokes should be at the 9 o’clock and 3 o’clock posi-

tions, or within 10 degrees to either side. See

Fig. 5.14. See Group 46 of the Saf-T-Liner C2

School Bus Workshop Manual for steering adjust-

11/14/2001

f461922

ment procedures.

Push the foot pedal down to adjust the steering column.

On some vehicles, the steering column may be tilted

1. Steering Wheel

3. Foot Pedal

forward or aft to provide the most comfortable angle

2. Steering Column

for steering the vehicle. The steering column can

Fig. 5.15, Adjustable Steering Column

also be telescoped (raised or lowered) to provide the

most comfortable height above the floor.

5.7

Controls

To telescope the steering column, press down on the

foot pedal to release the steering column lock. Pull

the steering wheel upwards or push the steering

wheel downwards until it is at the desired height. Re-

lease the foot pedal to lock the steering column in

place.

NOTE: For safety, the steering column is locked

at all times unless the foot pedal is pressed

down.

Powertrain Controls

Cruise Control Switch

WARNING

Do not use the cruise control system when driv-

ing conditions do not permit maintaining a con-

stant speed, such as heavy traffic or on roads

09/13/2001

f610510

that are winding, icy, snow covered, slippery, or

To turn the cruise control on, press the upper half of the

roads with a loose driving surface. Failure to fol-

On/Off (rocker) switch. To turn cruise control off, press

low this precaution could cause a collision or

the lower half of the On/Off (rocker) switch.

loss of vehicle control, possibly resulting in per-

1. Cruise Control On/Off (rocker) Switch

sonal injury or property damage.

2. Cruise Control Set/Resume (paddle) Switch

NOTE: Maximum cruise control speed varies

Fig. 5.16, Cruise Control Switches, Dash-Mounted

according to vehicle specifications, but cannot

1.3

Momentarily lower the Set/Resume switch

be higher than 75 mph (121 km/h).

paddle.

On standard models, cruise control is activated by

2. To disengage the cruise control, do these steps:

two dash switches. See Fig. 5.16. On some models,

the cruise control can be activated by a button on the

2.1

Depress the brake pedal.

transmission shift knob.

2.2

Press the lower half of the On/Off rocker

• The On/Off Switch—this two-position rocker

switch on the instrument panel.

switch bears the legend SPD CNTL on the

3. To resume a preselected cruise speed, do these

lower half of the switch. When the cruise con-

steps:

trol is on, an amber light illuminates in the top

part of the switch.

3.1

If the On/Off rocker switch on the instru-

ment panel is off, turn it on.

• The Set/Resume Switch—this three-position

paddle switch bears the legend RES/ACC

3.2

Momentarily raise the paddle of the Set/

above the paddle and SET/CST below the

Resume switch to RES/ACC. Cruise will

paddle.

return to the last speed selected.

1. To cruise at a particular speed, do these steps:

NOTE: If the ignition is shut off, the speed

1.1

Press the upper half of the On/Off rocker

memory will be lost.

switch on the instrument panel.

4. To adjust cruise speed up, raise the paddle of

1.2

Hold the accelerator pedal down until the

the Set/Resume switch to RES/ACC and hold it

speedometer reaches the desired speed.

there until the vehicle accelerates to the new

speed, as desired.

5.8

Controls

5. To adjust the cruise speed down, lower the

To turn the exhaust brake on, press the upper part of

paddle of the Set/Resume switch to SET/CST

the rocker switch. The exhaust brake turns off auto-

and hold it there until the vehicle decelerates to

matically. See Fig. 5.17.

the new speed, as desired.

NOTE: For more information about cruise con-

trol operation, see the engine manufacturer’s

service manual.

Fast Idle System

If the vehicle has this feature, it is available for use

only with cruise control. There are three preset

speeds available: 800, 900, or 1000 rpm.

The fast idle system can be used to increase engine

idle speed whenever the following conditions are

11/28/2001

f610589

met.

Fig. 5.17, Exhaust Brake Switch

• The brake pedal is not pressed.

• The vehicle must not be moving and the

When the exhaust brake switch is on, an amber LED

throttle must not be pressed.

illuminates inside the switch. When the panel lights

are on, the EXHST BRK legend is backlit in green.

Fast Idle Operation

Transmission Controls

1. To enable the fast idle system, press and release

the cruise control On/Off rocker switch.

If so equipped, the transmission range control valve

and splitter valve are attached to the gearshift knob.

2. For the preset fast idle, press and release the

Transmission shift pattern labels are located inside

cruise control set switch. This will set the preset

the cab. See Chapter 9 for complete transmission

fast idle speed.

operating instructions.

IMPORTANT: The fast idle system does not

Vehicles equipped with a standard Allison On-

have any type of light activation in the instru-

Highway Series automatic transmission, have a

ment panel. The only light that will be illumi-

T-handle shift selector. See Fig. 5.18.

nated is the cruise indicator.

When the transmission is in D (drive), the vehicle will

Any of the following actions will turn off the fast idle

operate in 4th and 5th gear as needed. To shift down

system:

into a lower gear, pull the lower half of the T-handle

selector up. Select the gear needed and release the

• Applying the brake.

lower half of the T-handle selector.

• The transmission shifter is moved out of Park

On vehicles with an Allison MD Series automatic

(P) or Neutral (N); this will engage the trans-

transmission or an Eaton Autoshift automated trans-

mission.

mission, a push-button shift selector, shown in

Fig. 5.19, provides four, five, or six forward ranges

• Pressing and releasing the cruise control On/

and one reverse range. See Chapter 9 for more in-

Off rocker switch when it is on.

formation about the push-button shift selector.

Exhaust Brake Switch

Axle Switches

An exhaust brake is an optional auxiliary braking sys-

All axle switches contain a red LED that illuminates

tem that assists, but does not replace the service

the switch from within when the switch is turned on

brake system. The exhaust brake is controlled by a

(the upper part of the rocker is pressed). The legend

dash-mounted rocker switch to help slow the vehicle

under the LED, if any, is not visible until the switch is

when the accelerator is released.

turned on.

5.9

Controls

07/27/2006

f610804

1. Digital Display

3. Mode Indicator LED

2. Mode Identification

4. Mode Button

Label

Fig. 5.19, Push-Button Shift Selector

Differential Lock Switch

NOTICE

Differential lock should only be engaged when

the vehicle is stopped or moving slowly at low

throttle. This will prevent internal axle damage.

The differential lock switch is a two-position guarded

rocker switch. It causes the wheels on each axle

governed by the switch to rotate together. It is also

known as side-to-side wheel lock. See Fig. 5.20.

09/21/2012

f270165

Fig. 5.18, T-Handle Shifter

IMPORTANT: A guard is positioned around all

axle switches to prevent unintentional activation.

NOTE: For more information on axle switch

function, see Chapter 9.

10/26/2001

f610596

Fig. 5.20, Differential Lock Switch

To lock the wheels together, press the upper half of

the rocker switch momentarily. To turn off differential

lock, press the upper half of the rocker switch again.

5.10

Controls

When the panel lights are on, the double-axle icon is

Backup Alarm

backlit in green.

The backup alarm sounds when Reverse (R) gear is

IMPORTANT: The differential lock switch is

engaged. Check the operation of the backup alarm

guarded to prevent unintentional switch activa-

daily (if so equipped).

tion. If the LED in the switch begins to blink dur-

ing normal operation, when the switch has not

Braking Controls

been activated, this indicates an error condition.

Take the vehicle to an authorized Freightliner

Parking Brake Control Valve

dealer as soon as possible.

The yellow diamond-shaped knob on the auxiliary

dash panel operates the parking brake control valve

Interaxle Lock Switch

(park brake switch). See Fig. 5.22. Pull the knob to

apply the parking brakes; push the knob in to release

NOTICE

the parking brakes. Before the parking brakes can be

released, the air pressure in either air brake system

Do not turn the interaxle lock switch on when the

must be at least 65 psi (448 kPa).

tires are slipping. Do not continuously operate

the vehicle with the interaxle lock engaged dur-

ing good road conditions. To do so could result

in damage to the axle gearing and excessive tire

wear.

The interaxle lock switch is a two-position guarded

rocker switch installed on vehicles with dual drive

axles. It causes both axle shafts to rotate together.

See Fig. 5.21.

12/10/2003

f430360

1. Parking Brake Control Valve

Fig. 5.22, Parking Brake Control Valve

See Chapter 10 under the heading "Dual Air Brake

System" for further information about the parking

brake control valve.

Meritor^™ WABCO® Antilock Braking

10/26/2001

f610595

System (ABS)

Fig. 5.21, Interaxle Lock Switch

The Meritor WABCO ABS has an amber indicator

light (ABS legend) and, if equipped with automatic

To lock the axles together, press the upper half of the

traction control (ATC), an amber wheel spin indicator

rocker switch momentarily. To turn off interaxle lock,

light (WHEEL SPIN legend). See Fig. 5.23.

press the upper half of the rocker switch again.

See the brake system operating instructions in Chap-

When the panel lights are on, the double-axle icon is

ter 10 for more information about ABS.

backlit in green.

IMPORTANT: The interaxle lock rocker switch is

Heater/Air Conditioner/Defrost

guarded to prevent unintentional switch activa-

Control Panel

tion. This switch does not have a diagnostic

blink function when inactive.

Standard controls for the heating, ventilation, defrost-

ing, and air-conditioning system (HVAC) consist of an

5.11

Controls

able on a system without air conditioning. See

LOW

WAIT TO

DEF

WHEEL

RANGE

CHECK

OPT 1

WATER

START

QUALITY

SPIN

INHIBIT

TRANS

OPT 8

OPT 9

Fig. 5.26. A system with air conditioning has 11 air

CHECK

STOP

ABS

selection modes, four of which are air conditioning

modes. See Fig. 5.27.

BRAKE

Air Selection Switch Without Air

AIR

Conditioning

Face Mode: Directs all airflow through the face

06/19/2012

f611198

or instrument panel outlets.

1. Wheel Spin Indicator

2. Tractor ABS Indicator

Selection between Face Mode and Bi-Level

Fig. 5.23, ABS Indicator Lights

Mode: Directs 75 percent of the airflow through

the face outlets and 25 percent through the floor

eight-speed fan switch, an air selection switch, and a

outlets.

temperature control switch. See Fig. 5.24. On ve-

Bi-Level Mode: Directs the airflow equally to the

hicles with air conditioning, the panel also contains a

face outlets and the floor outlets.

telltale LED and an air recirculation button.

Selection between Bi-Level Mode and Floor

Climate Control Panel

Mode: Directs 25 percent of the airflow through

the face outlets and 75 percent through the floor

The climate control panel controls the HVAC for the

outlets.

driver. The climate control panel without air condition-

ing is shown in Fig. 5.24. The climate control panel

Floor Mode: Directs all airflow through the floor

with air conditioning is shown in Fig. 5.25.

outlets.

NOTE: The bus may be equipped with a We-

Selection between Floor Mode and Floor/

basto heating system. The Webasto heating

Defrost Mode: Directs 75 percent of the airflow

through the floor outlets and 25 percent through

system warms the engine prior to starting the

the defrost outlets.

bus, and also assists in generating additional

heat for the passengers during operation. For

Floor/Defrost Mode: Directs the airflow equally

operating instructions see the Webasto Opera-

to the floor outlets and the defrost outlets.

tor’s Manual.

Selection between Floor/Defrost Mode and

Defrost Mode: Directs 75 percent of the airflow

Fan Switch

through the defrost outlets and 25 percent

through the floor outlets.

The fan switch controls the fan speed, and forces

fresh or recirculated air through the air outlets. The

Defrost Mode: Directs all airflow through the

fan switch has eight fan speeds and an off position.

defrost outlets.

To increase airflow, turn the fan switch clockwise to a

Air Selection Switch With Air

higher number. To decrease the airflow, turn the

switch counterclockwise to a lower number.

Conditioning

1. Air Conditioning Face Mode: Directs all airflow

Passenger Heater Switch

through the face or instrument panel outlets.

The underseat heater switches allow the driver to

2. Selection between the Air Conditioning Face

control the fan speed of the underseat heaters.

Mode and the Air Conditioning Bi-Level

Mode: Directs 75 percent of the airflow to the

Air Selection Switch

face outlets and 25 percent to the floor outlets.

The air selection switch allows the driver to control

3. Air Conditioning Bi-Level Mode: Directs the

the flow of air through the face outlets, the floor out-

airflow equally to the face outlets and the floor

lets, the defrost (windshield) outlets, or a combination

outlets.

of these outlets. Nine air selection modes are avail-

5.12

Controls

06/17/2003

f831452a

1. Fan Switch

2. Air Selection Switch

3. Temperature Control Switch

Fig. 5.24, Climate Control Panel Without Air Conditioning

06/18/2003

f831453a

1. Fan Switch

3. Temperature Control Switch

5. Recirculation Indicator

2. Air Selection Switch

4. Recirculation Button

Fig. 5.25, Climate Control Panel With Air Conditioning

4. Selection between the Air Conditioning Bi-

8. Selection between Floor Mode and Floor/

Level Mode and the Face Mode: Directs 25

Defrost Mode: Directs 75 percent of the airflow

percent of the airflow to the face outlets and 75

through the floor outlets and 25 percent through

percent to the floor outlets.

the defrost outlets.

5. Face Mode: Directs all airflow through the face

9. Floor/Defrost Mode: Directs the airflow equally

outlets.

to the floor outlets and the defrost outlets. The

recirculation button will not work in this mode.

6. Selection between Face Mode and Floor

Mode: Directs the airflow equally through the

10. Selection between Floor/Defrost Mode and

face outlets and the floor outlets.

Defrost Mode: Directs 75 percent of the airflow

through the defrost outlets and 25 percent

7. Floor Mode: Directs all airflow through the floor

through the floor outlets. The recirculation button

outlets.

will not work in this mode.

5.13

Controls

06/18/2003

f831462

06/17/2003

f831455

A. Air Conditioning Modes

1. Face Mode

1. Air Conditioning Face Mode

2. Selection Between Face Mode and Bi-Level Mode

2. Selection Between Air Conditioning Face Mode and

3. Bi-Level Mode

Air Conditioning Bi-Level Mode

4. Selection Between Bi-Level Mode and Floor Mode

3. Air Conditioning Bi-Level Mode

5. Floor Mode

4. Selection Between Air Conditioning Bi-Level Mode

6. Selection Between Floor Mode and Floor/Defrost

and Face Mode

Mode

5. Face Mode

7. Floor/Defrost Mode

6. Selection Between Face Mode and Floor Mode

8. Selection Between Floor/Defrost Mode and Defrost

7. Floor Mode

Mode

8. Selection Between Floor Mode and Floor/Defrost

9. Defrost Mode

Mode

Fig. 5.26, Air Selection Switch Without Air Conditioning

9. Floor/Defrost Mode

10. Selection Between Floor/Defrost Mode and Defrost

11. Defrost Mode: Directs all airflow through the

Mode

11. Defrost Mode

defrost outlets. The recirculation button will not

work in this mode.

Fig. 5.27, Air Selection Switch With Air Conditioning

Temperature Control Switch

The recirculation mode can also be used to decrease

the time required to cool or heat the cab interior dur-

The temperature control switch is used to select the

ing extreme outside temperature conditions. When

desired temperature. Turn the switch to the left

the recirculation mode is on, the recirculation indica-

(counterclockwise) for cool air, or to the right (clock-

tor will illuminate. See Fig. 5.25.

wise) for hot air. There are 21 positions on the tem-

perature control switch, ranging from full cool air to

The recirculation mode is not available when the air

full hot air.

selection switch is in one of the following modes:

• floor/defrost mode

Fresh Air Mode

• selection between floor/defrost mode and de-

Fresh air, or outside air, is circulated through the

frost mode

heating and air conditioning system unless the recir-

culation mode, if equipped, is turned on.

• defrost mode

When the recirculation mode is turned on, it will stay

Recirculation Mode

on for 20 minutes, or until the recirculation button is

pressed again, or the air selection switch is turned to

The recirculation mode is only available on vehicles

a defrost mode.

with air conditioning.

IMPORTANT: The system enters a partial recir-

The recirculation mode limits the amount of outside

culation mode for five minutes after being in full

air entering the cab. Press the recirculation button to

prevent dusty or smoky air from entering the cab.

recirculation mode for 20 minutes. This cycle

5.14

Controls

repeats as long as the system is in recirculation

mode.

Defrosting

Before using any of the defrost modes, clear the

screen at the base of the windshield if snow or ice is

present.

Air Conditioning

There are four air conditioning modes on the air se-

lection switch. The air conditioning settings on the air

selection switch are blue, in addition to the selection

between the air conditioning bi-level mode and the

face mode.

IMPORTANT: Operate the air conditioner at

least five minutes each month, even during cool

weather. This helps prevent drying and cracking

of the refrigerant compressor seals and reduces

the chance of refrigerant leaks in the system.

NOTE: The heating and air conditioning system

has a brushless blower motor with a protection

or shutdown mode to prevent damage due to

overheating and overcurrent conditions. If the

brushless blower motor goes into a protection

mode, the motor will operate at a slower speed.

If the overheating or overcurrent condition con-

tinues, the motor will shut down and stop com-

pletely.

The motor will resume proper operation after the

motor has cooled or the overcurrent condition

has been resolved. It will be necessary to cycle

the fan switch off, and then on, to reset the

motor. If the problem appears repeatedly, take

the vehicle to an authorized Freightliner dealer

for repairs.

Booster Pump

The booster pump switch activates an auxiliary cool-

ant booster pump to circulate coolant to the heaters

when the engine is idling or when stop-and-go driv-

ing conditions reduce coolant flow due to low engine

rpm.

5.15

Electrical Systems

Because the electrical system is multiplexed, no re-

Electrical System General

lays are needed. The multiplexing module performs

Information

the functions normally provided by relays.

The Saf-T-Liner C2 uses an electrical system where

Fuse Identification

multiple electrical signals are carried along a simpli-

CAV

Description

Fuse

fied set of wires, reducing the size of wiring bundles.

VCU (spare)

10A (—)

There are significantly fewer wires overall, meaning

Blower Motor

30A

less chance of damage, shorts, and other problems.

The information in this chapter is to help familiarize

Engine ECU

20A

the driver with the basic electrical system. Servicing

RR Wall HTR RLY LO/HI

30A

the electrical system requires special skills and

Ignition Switch

10A

equipment and should only be performed by a quali-

Hydromax RLY (spare)

30A (—)

fied technician. Take the vehicle to an authorized

Stepwell HTR RLY LO/HI

30A

Thomas Built Bus dealer when service is needed.

ICU3-M2

10A

Transmission ECU

10A

WARNING

F10

Expansion Module 1

30A

F11

Expansion Module 1

30A

Do not attempt to modify, add, splice, or remove

F12

Radio/Diagnostic

20A

electrical wiring on this vehicle. Doing so could

F13

Expansion Module 1

30A

damage the electrical system and result in a fire

F14

Expansion Module 2

30A

that could cause serious personal injury or prop-

F15

Bulkhead Module

30A

erty damage.

F16

ABS ECU

15A

F17

Chassis Module

30A

Power Distribution Modules

F18

Bulkhead Module

30A

There are two power distribution modules (PDAs).

F19

Chassis Module

30A

F20

Bulkhead Module

30A

The main PDM is located under the hood on the

F21

Expansion Module 2

30A

driver’s side above the fender. See Fig. 6.1. The

F22

Bulkhead Module

30A

main PDM distributes battery power to the vehicle’s

F23

Expansion Module 2

30A

control modules, and contains the fuses required to

protect the power feed circuits to these modules.

F24

Hydraulic Pump and RLY (spare)

25A (—)

While the main PDM provides power to the modules,

F25

Adjustable Pedals

10A

the modules themselves control power flow and cir-

F26

Chassis Module

30A

cuit protection to the various components of the vehi-

F27

Heater Booster Pump

20A

cle’s electrical systems. Because of this, traditional

F28

Bulkhead Module

30A

PDM devices such as relays and circuit breakers are

F29

Crossing Arm RLY

10A

no longer necessary on the main PDM.

Table 6.1, Main PDM Fuse Identification

Inside the lid of the fuse box there is a sticker that

shows the location of the fuses and describes the

circuit(s) that each fuse protects. Fuse configuration

will vary depending on the PDM assembly installed.

See Fig. 6.2. See Table 6.1 for descriptions of a

typical set of fuses.

The cab PDM is located in the switch panel cavity at

the driver’s left elbow and handles circuits inside the

vehicle, such as heaters, doors, fans, lights, and

other interior accessories. See Fig. 6.3.

6.1

Engines

Engine Starting

WARNING

For cold-weather starting, refer to the Cummins Op-

Never start the engine unless the parking brake

eration and Maintenance Manual for detailed instruc-

is applied. Accidental movement of the vehicle

tions.

could result in property damage, personal injury,

or death.

General Information

IMPORTANT: Do not depress the throttle pedal

NOTE: Before starting the engine, read Chap-

while starting the engine.

ter 4 and Chapter 5 in this manual for detailed

information on how to read the instruments and

4. Turn the ignition switch to the START position.

operate the controls.

After the engine starts, release the key.

Before operating the vehicle, perform the engine pre-

trip inspection and daily maintenance checks in

NOTICE

Chapter 11 and Chapter 12 of this manual.

Do not crank the engine for more than 30 sec-

onds at a time. Wait two minutes after each try to

NOTICE

allow the starter to cool. Failure to do so could

cause starter damage.

If a vehicle does not start on the first attempt,

make sure that the engine has completely

5. Bring the engine up to operating speed gradually

stopped rotating before reapplying the starter

as it warms up and develops stable oil pressure.

switch. Failure to do so can cause the pinion to

IMPORTANT: When the engine is started, it

release and re-engage, which could cause ring

takes a short time to build up a lubricating oil

gear and starter pinion damage.

film between the shafts and bearings, and be-

Moving a vehicle with the starter and/or using the

tween the pistons and cylinder walls. The oil

starter to bump the engine for maintenance pro-

pressure gauge indicates any drop in lubricating

cedures is strictly prohibited. Use of these meth-

oil pressure within 15 seconds of engine startup.

ods to bump the engine over or move the vehicle

See the Cummins Operation and Maintenance

can cause the pinion to release and re-engage,

Manual for minimum idle oil pressure specifica-

which could cause ring gear and starter pinion

tions.

damage.

Starting After Extended Shutdown or

NOTICE

Oil Change

Never attempt to start any Cummins IS series

NOTE: An engine in storage for an extended

electronic engine (ISB, ISC, ISL) using ether or

period of time (over winter, for example) may

any other starting fluid. Serious engine damage

could result.

accumulate water in the oil pan. Oil diluted by

water cannot provide adequate bearing protec-

1. Set the parking brake.

tion at start-up. For this reason, change the en-

2. Turn the ignition switch to the ON position.

gine oil and filters after extended storage.

The low air pressure and low oil pressure warn-

Do the following steps after an oil change or

ing lights (or messages) and buzzer operate until

after the engine has been shut down for more

the engine is started and pressure is built up.

than three days:

3. Make sure that the transmission shift control is in

1. Make sure the transmission is filled with the cor-

Neutral (N), or if so equipped, the Park (P) or

rect type of fluid, as recommended by the trans-

Park Brake (PB) position.

mission manufacturer.

7.1

Engines

2. Make sure the fuel tank is full. If air has entered

maintenance, and correct adjustments are factors

the fuel system, prime the fuel system, using the

that will help to stay within the regulations.

engine manufacturer’s instructions.

Adequate maintenance of the engine, which is the

3. If the engine is equipped with a fuel/water sepa-

responsibility of the owner/operator, is essential to

rator, drain off any accumulated water.

keep the emission levels low.

4. Check the drive belts to make sure they are in

The driver should be familiar with the vehicle warning

good condition and properly adjusted. Replace

system in order to bring the vehicle to a safe stop if

any drive belts that are cracked, worn, or glazed.

the engine malfunctions. If the driver doesn’t under-

stand how the warning system works, an engine

5. Check the turbocharger for signs of oil or ex-

shutdown could occur, causing a safety hazard. See

haust leaks. Correct any problems before starting

Chapter 5 for information on the control panel for

the engine.

these engines.

6. Check the engine mounting bolts for tightness.

Follow the directions in the Cummins Operation and

Retighten them if necessary.

Maintenance Manual and in this manual for trouble-

7. Make sure the battery cable connections are

free, economical vehicle engine operation.

clean and tight. Check that the batteries are

charged.

NOTICE

8. Start the engine. See the "Engine Starting" head-

Stop the engine at the first sign of malfunction.

ing in this chapter.

Almost all malfunctions give some warning to the

operator before significant damage occurs. Many

Engine Operation

engines are saved because alert operators heed

the warning signs (sudden drop in oil pressure,

IMPORTANT: For cold-weather starting, engine

unusual noises, etc.) and immediately shut down

break-in, and cold-weather operation, refer to

the engine.

the Cummins Operation and Maintenance

Manual for detailed instructions.

1. Cummins diesel engines are designed to operate

successfully at full throttle under transient condi-

Operating vehicles in areas where there are concen-

tions down to rated rpm. This is consistent with

trated flammable vapors (such as diesel, gasoline, or

recommended operating practices.

propane fumes) can create a hazardous situation.

These vapors can be drawn into the engine through

2. Depending on the vehicle gearing, the posted

the air intake, and cause engine overspeed. Be es-

speed limit can sometimes allow operation in ei-

pecially cautious of low-lying or closed-in areas, and

ther of the top two gears; however, for improved

always check for signs that flammable vapors may

operating efficiency (fuel economy and engine

be present.

life), operate in the top gear at reduced rpm

rather than in the next lower gear at the maxi-

mum rpm.

DANGER

3. Cruise at partial throttle whenever road condi-

Do not operate the engine in an area where flam-

tions and speed requirements permit. This driv-

mable vapors such as gasoline or diesel fumes

ing technique permits operating within the most

are present. Shut down the engine when in an

economical power range of the engine.

area where flammable liquids or gases are being

4. When approaching a hill, open the throttle

handled. Failure to observe these precautions

smoothly to start the upgrade at full power, then

could result in serious injury or death.

shift down as desired to maintain the optimum

All diesel engines have been built to comply with the

vehicle speed. The high torque of Cummins en-

requirements of the Federal (U.S.) Clean Air Act.

gines may permit topping some grades without

Once an engine is placed in service, the responsibil-

shifting.

ity for meeting both state and local regulations is with

5. Cummins engines are designed to operate over

the owner/operator. Good operating practices, regular

a wide speed range. More frequent shifting than

7.2

Engines

necessary does not allow proper utilization of this

High Idle Options

flexibility. The driver who stays in top gear and

uses the wider speed range will achieve the best

NOTE: To operate the high idle options listed

fuel economy.

below, the vehicle must be stopped, the trans-

mission shift lever placed in the Neutral (N) or

6. The Cummins diesel engine is effective as a

Park (P) position, and the parking brake set.

brake on downhill grades, but take care not to

overspeed the engine going downhill. The gover-

IMPORTANT: Do not idle the engine for exces-

nor has no control over engine speed when the

sively long periods. The extreme heat can cause

engine is being pushed by the loaded vehicle.

the bearings to seize or the oil seals to leak.

NOTICE

High Idle with Cruise Control

Do not allow the engine to exceed its governed

1. Place the shift lever in Neutral (N) or Park (P)

and set the parking brake.

speed, or serious engine damage could result.

2. Press the cruise switch located on the dash to

7. Never turn the ignition switch to the OFF position

the ON position. Press the RESUME switch to

while going downhill. With the engine still in gear,

accelerate the engine revolutions per minute

fuel pressure will build up against the shutdown

(rpm) to the minimum set speed. To increase the

valve and can prevent it from opening when the

engine rpm, press and hold the RESUME switch.

ignition switch is turned to the ON/RUN position.

To decrease the engine rpm, press and hold the

8. Use a combination of brakes and gears to keep

SET switch.

the vehicle under control at all times, and to

keep the engine speed below the rated governed

NOTE: The rpm can also be increased by de-

rpm.

pressing the throttle pedal until the desired rpm

is met, and then pressing the SET switch.

9. Check the coolant temperature and oil pressure

gauges frequently.

3. Disengage the cruise control by depressing the

service brake pedal, or by moving the ON/OFF

switch to the OFF position.

NOTICE

Voltage-Based Auto High Idle

Continuous operation below 140°F (60°C), above

212°F (100°C), or with the oil pressure below 10

1. Place the shift lever in Neutral (N) or Park (P)

psi (69 kPa), can damage the engine.

and set the parking brake.

10. Do not idle the engine for more than 10 minutes.

2. The idle rpm will automatically increase when the

Long periods at low idle can damage the engine.

voltage drops below 12.2 volts. The rpm will in-

crementally increase every five seconds until

NOTE: Long periods of idling are not good for

13.4 volts is achieved and maintained.

an engine because the combustion chamber

temperatures drop so low that the fuel may not

3. The Voltage-Based Auto High Idle system is dis-

burn completely. This will cause carbon to clog

engaged by depressing the service brake pedal.

the injector spray holes and piston rings, and

IMPORTANT: The Voltage-Based Auto High Idle

can result in stuck valves.

system will not return to normal operation until

11. If the engine starts to overheat, reduce the

one of the following occurs: The parking brake

power output of the engine. Do one, or both, of

is depressed and released, the key switch is

the following: (1) Release pressure on the accel-

turned to the OFF position, or the transmission

erator pedal; (2) Shift to a lower gear. If the tem-

gears are changed.

perature does not return to normal, shut down

the engine.

7.3

Engines

Engine Shutdown

Shut down the engine immediately if:

• the oil pressure gauge needle swings back and

forth or falls sharply;

• engine power and rpm fall, even though the

accelerator pedal remains steady;

• the exhaust pipe gives off heavy smoke;

• the coolant and/or oil temperature climb abnor-

mally;

• abnormal sounds suddenly occur in the engine

or turbocharger.

IMPORTANT: Bearings and seals in the turbo-

charger are subjected to the high heat of com-

bustion exhaust gases. While the engine is run-

ning, this heat is carried away by oil circulation,

but if the engine is stopped suddenly, the turbo-

charger temperature may rise as much as 115°F

(46°C).

1. With the vehicle stopped, place the transmission

in Neutral (N), or if so equipped, the Park (P) or

Park Brake (PB) position.

2. Set the parking brake.

3. Idle the engine for three to five minutes before

shutting it down. This allows the lubricating oil

and the coolant to carry heat away from the

combustion chambers, bearings, shafts, etc. This

is especially important with turbocharged en-

gines. The extreme heat can cause bearings to

seize or oil seals to leak.

NOTE: Long periods of idling are not good for

an engine because the combustion chamber

temperatures drop so low that the fuel may not

burn completely. This will cause carbon to clog

the injector spray holes and piston rings, and

can result in stuck valves.

NOTICE

Do not rev the engine before shutting it down.

Revving the engine before shutdown will damage

the turbocharger.

4. Shut down the engine by turning the ignition

switch to the OFF position.

7.4

Exhaust Aftertreatment Systems

• Use only certified diesel exhaust fluid (DEF)

Aftertreatment System, EPA10

in the DEF tank.

and Newer Engines

IMPORTANT: Using non-specification fuels or

Engines manufactured between January 1, 2010 and

oils can lead to shortened diesel particulate filter

December 31, 2012 meet EPA10 requirements. En-

(DPF) cleaning or replacement intervals. For

gines manufactured from January 1, 2013 meet

example, using CJ-4+ oil with 1.3% sulfated ash

NHTSA and EPA 2014 fuel efficiency and green-

(30% more ash content) may result in the need

house gas emission standards (GHG14) require-

for DPF cleaning or replacement 20 to 30%

ments.

sooner than would normally be required.

Model year 2013 and later vehicles meet additional

IMPORTANT: See the engine manufacturer’s

requirements as specified by GHG14 requirements.

operation manual for complete details and op-

These vehicles are equipped with components that

increase fuel efficiency and reduce GHG emissions.

eration of the ATS.

After exhaust gasses leave the engine, they flow into

IMPORTANT: Depending on local jurisdictional

the ATS. First they flow into a two-part ATD, com-

guidelines, vehicles that are domiciled outside of

prised of a diesel oxidation catalyst (DOC), and a

the U.S. and Canada may not have emissions

diesel particulate filter (DPF). The DPF traps soot

aftertreatment systems (ATS) that are compliant

particles, then exhaust heat converts the soot to ash

with EPA regulations.

in the DPF, in a process called regeneration (regen).

The harder an engine works, the better it disposes of

Principles of Operation

soot. When the engine is running under load and

regen occurs without input, it is called passive regen.

The EPA mandates that all engines built after De-

If the engine isn’t running hot enough, the electronic

cember 31, 2009 must reduce the level of emissions

controls may initiate an active regen, whereby extra

exhausted by the engine to the following levels:

fuel is injected into the exhaust stream before the

• Nitrogen Oxides (NOx) - 0.2 g/bhp-hr

diesel particulate filter, to superheat the soot trapped

in the filter and burn it to ash. Both types of regen

• Particulate Matter (PM) - .01 g/bhp-hr

occur without driver input.

To meet EPA guidelines, engines that are compliant

with EPA10 and newer regulations use an aftertreat-

WARNING

ment system (ATS) with an aftertreatment device

(ATD) and Selective Catalytic Reduction (SCR) tech-

Active regeneration can occur automatically any-

nology to reduce NOx downstream of the engine.

time the vehicle is moving. The exhaust gas tem-

perature could reach 1500°F (816°C), which is hot

NOTICE

enough to cause a fire, heat damage to objects

or materials, or personal injury to persons near

Follow these guidelines for engines that comply

the exhaust outlet. See Regen-Inhibit Switch later

with EPA10 or newer regulations, or damage may

in this chapter for instructions on preventing au-

occur to the ATD and the warranty may be com-

tomatic regen if necessary.

promised.

The exhaust temperature can remain high even

• Use ultralow-sulfur diesel with 15 ppm sul-

after the vehicle has stopped. When stopping the

fur content or less.

vehicle shortly after an automatic regen, ensure

the exhaust outlets are directed away from struc-

• Do not use fuel blended with used engine

tures, trees, vegetation, flammable materials, and

lube oil or kerosene.

anything else that may be damaged or injured by

• Engine lube oil must have a sulfated ash

exposure to high heat.

level less than 1.0 wt %; currently referred

Operating at reduced engine load will allow soot to

to as CJ-4 oil.

accumulate in the DPF. When this occurs, the DPF

lamp illuminates, indicating that a regen must be per-

formed, and the driver must either bring the vehicle

8.1

Exhaust Aftertreatment Systems

up to highway speed to increase the load, or park

A reference label is included with the driver’s docu-

the vehicle and initiate a parked regen. See Parked

mentation package initially in the glove box, that ex-

Regen, later in this chapter for instructions.

plains the ATS warnings, and actions required to

avoid further engine protection sequences. See

After the exhaust stream passes through the ATD, it

Fig. 8.1.

flows through another canister housing the SCR de-

vice. A controlled quantity of DEF is injected into the

The regen switch, located on the dash, is used to

exhaust stream, where heat converts it to ammonia

initiate a parked regen of the aftertreatment device.

(NH₃) gas. This mixture flows through the SCR de-

See Fig. 8.2.

vice, where the ammonia gas reacts with the NOx in

NOTE: The regen switch can initiate a parked

the exhaust, to produce harmless nitrogen (N₂) and

regen only when the DPF lamp is illuminated

water vapor (H₂O), which then exits out of the tail-

(because the engine software is signaling for a

pipe.

parked regen).

ATS Warning Lamps

The regen-inhibit switch (optional when available)

provides additional control over the aftertreatment

Warning lamps in the driver’s message center alert

regeneration process. Depressing the regen-inhibit

the driver of situations with the ATS.

switch will prevent a regen from occurring during a

• An illuminated DPF lamp indicates a regen is

drive cycle. After the vehicle has been shut down

needed.

and restarted, regens will occur normally unless the

inhibit switch is pressed again. See Fig. 8.3.

• A slow, 10-second flashing of the HEST lamp

alerts the driver that a parked regen is in prog-

To initiate a parked regeneration, perform the follow-

ress, but the exhaust temperatures are still

ing steps.

relatively cool. It also indicates that the high-

1. Park the vehicle away from all combustible and

idle speed is being controlled by the engine

flammable materials. Chock the tires. Start and

software, not the driver.

warm the engine until the coolant temperature is

• A steadily illuminated HEST lamp alerts the

at least 150°F (66°C).

operator of high exhaust temperatures when

2. Set the parking brake. If the parking brake was

vehicle speed is below 5 mph (8 km/h) while it

already set, you must release it, then set it

is performing an automatic regen, and during a

again.

parked regen.

If the vehicle has a two-pedal automated trans-

• An illuminated DEF warning lamp in the gauge,

mission, shift it into gear, then back to neutral.

indicates that the DEF tank should be refilled

at the next opportunity.

IMPORTANT: The driver must remain with the

vehicle during the entire regen cycle.

Parked Regen

3. Press and hold the regen switch for 4 seconds.

The engine will increase rpm and initiate the

DANGER

regen process.

During parked regeneration, exhaust tempera-

4. After the parked regen has run for 20 to 40 min-

tures are very high, and could cause a fire, heat

utes, the regen cycle is completed. The engine

damage to objects or materials, or personal in-

idle speed will drop to normal, and the vehicle

jury to persons near the exhaust outlet.

may be driven normally. The HEST lamp may be

illuminated, but will go out when the vehicle

Before initiating a parked regeneration, make cer-

speed exceeds 5 mph (8 km/h), or the system

tain the exhaust outlets are directed away from

has cooled to normal operating temperature.

structures, trees, vegetation, flammable materi-

als, and anything else that may be damaged or

5. To stop a parked regen at any time during the

injured by prolonged exposure to high heat.

process, depress the brake or throttle pedal, or

turn off the engine.

8.2

Exhaust Aftertreatment Systems

EXHAUST AFTERTREATMENT SYSTEM INFORMATION

INDICATOR

WARNING

CHECK

STOP

LAMP(S)

(Solid)

(Flashing)

Level 1

Level 2

Level 3

Level 4

Indicator Lamp

Filter Regeneration

Parked Regeneration

Parked Regeneration Required −

HEST (High Exhaust

Message(s)

Recommended

Necessary

Required − Engine

Engine Shut Down

System Temperature)

Derate

Flashing

Diesel Particulate

Filter is reaching

Filter is now

Filter has reached

Filter has exceeded

Filter Condition

capacity.

reaching maximum

maximum capacity.

maximum capacity

A regeneration is in

capacity.

progress.

Required Action

Bring vehicle to

To avoid engine

Vehicle must be

Vehicle must be parked and a

highway speeds to

derate bring vehicle

parked and a Parked

Parked Regeneration or Service

Solid

allow for an Automatic

to highway speeds

Regeneration must

Regeneration must be performed.

Exhaust Components

Regeneration or

to allow for an

be performed −

Check engine operator’s manual

and exhaust gas are

perform a Parked

Automatic

engine will begin

for details −engine will shut down.

at high temperature.

Regeneration.

Regeneration or

derate.

When stationary, keep

perform a Parked

away from people and

Regeneration as

flammable materials

soon as possible.

or vapors.

For a driver performed Parked Regeneration, vehicle must be equipped with a dash mounted Regeneration Switch.

See Engine Operator’s Manual for complete Regeneration Instructions.

24−01583−000B

06/29/2009

f080147

Fig. 8.1, Exhaust-Aftertreatment Warnings Reference Label

06/19/2012

f611199

07/30/2009

f610944

Fig. 8.2, Regen Switch

Fig. 8.3, Regen Inhibit Switch (optional when available)

DPF Maintenance

Diesel Exhaust Fluid and Tank,

Eventually ash will accumulate in the DPF and the

EPA10 and Newer Engines

filter will require servicing. DPF servicing must be

Diesel Exhaust Fluid

performed by an authorized technician, following the

engine manufacturer’s instructions. A record must be

Diesel exhaust fluid (DEF) is used in the ATS to

maintained for warranty purposes, that includes:

lower NOx in the exhaust stream. DEF is colorless

• date of cleaning or replacement;

and close to odorless (it may have a slightly pungent

odor similar to ammonia). It is nontoxic, nonflam-

• vehicle mileage;

mable, and biodegradable. It is mildly corrosive to

• particulate filter part number and serial number.

8.3

Exhaust Aftertreatment Systems

aluminum, but does not affect the strength or struc-

amber when the fuel level drops below 1/8th of the

ture of the aluminum.

capacity.

White crystals may be noticeable around compo-

The lower portion of the gauge has a DEF warning

nents that come into contact with DEF. The crystals

lamp that illuminates when the DEF tank is near

are easily removed with water.

empty, and a DEF lightbar that indicates the level in

the DEF tank as follows.

DEF consumption varies depending on ambient con-

ditions and vehicle application.

• Four bars illuminated green—Between 75%

and 100% full

Freezing Conditions

• Three bars illuminated green—Between 50%

DEF freezes to slush at around 12°F (-11°C). It is not

and 75% full

damaged or destroyed if frozen, and is fully usable

• Two bars illuminated green—Between 25%

when thawed. The DEF in the tank is allowed to

and 50% full

freeze while a vehicle is non-operational. At start-up,

normal operation of the vehicle is not inhibited if the

• One bar illuminated green—Between approxi-

DEF is frozen; an immersion heater with engine cool-

mately 10% and 25% full

ant flowing through it warms the DEF once the en-

• One bar illuminated amber—DEF very low, re-

gine is running, allowing the SCR system to operate.

fill DEF

Pre-2013 DEF supply lines are electrically-heated

• One bar flashing red—DEF empty, refill DEF

and are purged when the engine is shut down; com-

plete purging of the DEF lines requires approximately

five minutes after the engine is shut down.

DEF Warnings and Engine Limits

DEF supply lines with engine model year 2013 and

IMPORTANT: Ignoring the DEF warning lights

newer are designed to survive freezing conditions

and not refilling the DEF will result in limited en-

while containing DEF, so purging is not required.

gine power with a speed limit of 5 mph (8 km/h)

eventually being applied. See the Cummins Op-

DEF Tank

eration and Maintenance Manual for further in-

formation.

Engines that are compliant with EPA10 and newer

regulations are equipped with a DEF tank located

DEF Level Low—Initial and Critical

between the ATS and the fuel tank, or an optional

Warnings

location forward of the fuel tank. The DEF tank has a

19 mm filler neck inlet that prevents the hose from a

When the DEF level reads low the following warnings

diesel outlet from being inserted, and has a blue cap

strongly encourage the driver to refill the DEF tank.

for easy identification.

See Fig. 8.5.

The DEF tank will require filling a minimum of ap-

• The DEF warning lamp illuminates constantly

proximately every second diesel refuel depending on

(initial warning).

the DEF tank capacity. The Saf-T-Liner C2 School

Bus has an 11.5-gallon tank capacity. DEF consump-

• The DEF warning lamp flashes (critical warn-

tion is approximately 2% of fuel consumption, depen-

ing).

dent on vehicle operation. For every 50 gallons of

• DEF-level lightbar illuminates solid amber.

diesel fuel consumed, approximately 1 gallon of DEF

will be consumed.

DEF Empty

Fuel/DEF Gauge

When the DEF level reads empty, the following

lamps notify the driver. See Fig. 8.6.

The fuel and DEF levels are measured in a dual pur-

pose fuel/DEF gauge. See Fig. 8.4.

• One bar of the DEF-level indicator flashes red.

Fuel level is indicated at the top of the gauge. Below

• The DEF warning lamp flashes amber.

the fuel level, a low fuel warning lamp illuminates

• The CHECK engine lamp illuminates.

8.4

Exhaust Aftertreatment Systems

1/2

ULTRA LOW SULFUR

DIESEL FUEL ONLY

DEF

11/08/2010

f611037

A. Green bars—DEF level indicators.

C. One bar flashing red—DEF empty, refill DEF.

B. One bar illuminated amber—DEF very low, refill DEF.

1. Low Fuel Warning Lamp (amber at 1/8 tank of fuel)

2. Low DEF Warning Lamp

Fig. 8.4, Fuel/DEF Gauge

07/09/2009

f470537

07/09/2009

f470538

A. DEF Warning Lamp (solid amber)

NOTE: Engine power is limited.

B. DEF-Level Lightbar (1 bar solid amber)

A. DEF Warning Lamp (flashing amber)

B. DEF-Level Lightbar (1 bar flashing red)

Fig. 8.5, DEF Level Low Initial and Critical Warnings

Fig. 8.6, DEF Empty Warning

Engine performance is limited, with progressively

harsher engine power limits applied.

DEF Quality or SCR Tampering

The DEF tank must be filled to cancel the warning

sequence.

NOTICE

DEF Level Empty and Ignored

Once contaminated DEF or tampering has been

detected in the SCR system, the vehicle must be

If the empty warning is ignored and the DEF is not

taken to an authorized service center to check

refilled, the red STOP engine lamp illuminates in ad-

the SCR system for damage, and to deactivate

dition to the DEF warning lamp and the CHECK en-

the warning light and engine limits.

gine warning lamp. See Fig. 8.7.

If contaminated DEF or tampering is detected, the

If the DEF tank is not refilled, a 5 mph (8 km/h)

DEF warning light flashes, and engine power is lim-

speed limit will be applied after the next engine shut-

ited with progressively harsher limits applied. If the

down, or while parked and idling.

8.5

Drivetrain

When driving on icy or graveled surfaces, reduce

Driving Precautions

speed. Avoid sharp turning maneuvers.

The bus operator should use care when accelerating

or downshifting on slippery road surfaces. Sudden

Allison On-Highway

acceleration or engine braking, caused by shifting to

a lower gear range, can result in a loss of vehicle

Transmissions

control. This is very important on snow- or ice-

The Allison on-highway transmissions are fully auto-

covered roads. See Chapter 10 for brake operation.

matic and include the 2100 Series, 2200 Series,

If the bus is stuck in sand or mud, do not attempt to

2350 Series, 2500 Series, and 3000 Series. Refer to

pull the bus out under its own power. Request pro-

www.allisontransmission.com for additional infor-

fessional towing assistance.

mation.

Safety Precautions

NOTICE

2000 Series

Do not attempt to rock the vehicle. If rocking the

vehicle is necessary, even at low speeds, it may

WARNING

cause engine overheating, axle damage, trans-

mission damage or failure, or tire damage.

Do not leave the vehicle unattended with the en-

Do not coast the vehicle in neutral. Severe trans-

gine running. If you leave the vehicle and the en-

mission damage may result and the vehicle will

gine is running, the vehicle can move suddenly,

not have the benefit of engine braking.

which could result in personal injury or property

damage.

WARNING

On vehicles with Allison 2000 series transmissions,

do the following steps if you have to leave the ve-

To reduce the risk of personal injury, before

hicle with the engine running (for example, when

going down a steep or long grade, reduce speed

checking the transmission fluid).

and downshift the transmission. Do not hold the

brake pedal down too long or too often while

Without Auto-Apply Parking Brake

going down a steep or long grade. This could

cause the brakes to overheat, reducing their ef-

1. Bring the vehicle to a complete stop using the

fectiveness. As a result, the vehicle will not slow

service brake.

down at the usual rate. Failure to take these

2. Ensure that the engine is at low idle rpm.

steps could result in loss of vehicle control.

3. Put the transmission in neutral.

To avoid skidding on slippery roads, do not downshift

into L (low) at speeds above 20 mph (32 km/h).

4. Apply the parking brake, and make sure it is

properly engaged.

On slippery surfaces, avoid quick movements of the

steering wheel. Decrease speed and allow for extra

5. Chock the rear tires and take any other steps

stopping distance required by these conditions. For

necessary to keep the vehicle from moving.

non-ABS brakes, apply the brakes by pumping the

pedal steadily and evenly to avoid wheel lock-up and

With Auto-Apply Parking Brake

loss of vehicle control.

1. Bring the vehicle to a complete stop using the

Avoid driving through flooded areas unless you are

service brake.

sure the water is no higher than the bottom of the

2. Ensure that the engine is at low idle rpm.

wheel rims. Drive through slowly. Allow adequate

stopping distance since wet brakes do not grip well.

3. Put the transmission in PB (auto-apply parking

After driving through water, gently apply the brakes

brake).

several times while the vehicle is moving slowly to

4. Apply the parking brake (if so equipped), and

dry the brakes.

make sure it is properly engaged.

9.1

Drivetrain

5. Chock the rear tires and take any other steps

necessary to keep the vehicle from moving.

Range Inhibit Indicator, 2000 Series

A RANGE INHIBIT indicator is a standard feature of

the 2000 series transmissions. The RANGE INHIBIT

indicator comes on to alert the driver that transmis-

sion operation is being inhibited and that the range

shifts being requested by the driver may not occur.

When certain operating conditions are detected by

the transmission control module (TCM), the controls

will lock the transmission in the current operating

range.

Shift inhibits occur under the following conditions:

• Shifts from neutral to reverse or from neutral to

a forward range when the engine is above idle,

greater than 900 rpm.

• Forward/reverse directional shifts are typically

not permitted if appreciable output shaft speed

is detected.

• When some types of unusual transmission op-

erating conditions are detected by the TCM,

the TCM temporarily limits transmission opera-

tion until the vehicle can be driven to a service

location. When this type of situation is de-

tected, the TCM will lock the transmission in a

safe gear range.

• The TCM will prevent shifts from park or neu-

tral to another range when auxiliary equipment

is in operation.

• If a shift from a higher to a lower gear causes

the engine to overspeed.

09/21/2012

f270165

Operating Instructions, 2000 Series

Fig.

9.1, T-Handle Shifter (standard)

Transmissions

NOTE: This does not apply the parking brake.

2000 series transmissions are electronically con-

trolled. The shift selector provides four forward

The park pawl is standard on the 2200 series

ranges and one reverse range. A T-handle shift con-

transmission. The park pawl effectively grounds

trol is used by the driver to select the ranges. See

the transmission output shaft, thereby prevent-

Fig. 9.1.

ing rotation of the driveline. Provided the vehicle

P (Park)

is stationary, selecting P (park) on the shift se-

lector, if so equipped, places the transmission in

Use park, if so equipped, when turning the engine on

neutral and engages the park pawl.

or off, to check vehicle accessories, or to operate the

engine in idle for longer than 5 minutes. This position

places the transmission in neutral and engages the

park pawl of the transmission.

9.2

Drivetrain

PB (Auto-Apply Parking Brake, optional

selected. However, during downhill operation, the

transmission may upshift to the next higher range, if

on 2000 Series)

the engine is exceeding its governed speed in the

The auto-apply parking brake places the transmis-

lower range.

sion in neutral and applies the parking brake.

NOTE: The shift into drive may not succeed if a

R (Reverse)

range inhibitor is active. Check for illumination

of the RANGE INHIBIT indicator.

Reverse is used to back the vehicle. When the selec-

tor is in reverse, the reverse warning signal will

3 and 2 (Third and Second Ranges)

sound. Always bring the vehicle to a complete stop

before shifting from a forward range to reverse, or

Use the third or second range for heavy city traffic

from reverse to a forward range.

and for braking on steep downgrades.

Do not idle in reverse for more than 5 minutes. When

L (Low Range)

time at idle exceeds 5 minutes, select N (neutral), or

if so equipped, P (park) or PB (auto-apply parking

Use low range when pulling through mud or deep

brake).

snow, when maneuvering in tight spaces, or when

driving up or down very steep grades. Low range

NOTE: The shift into reverse may not succeed if

provides the vehicle with its maximum driving torque

a range inhibitor is active. Check for illumination

and maximum engine braking effect.

of the RANGE INHIBIT indicator.

NOTE: To have the transmission select these

N (Neutral)

ranges automatically, leave the selector lever in

D (drive).

The neutral position places the transmission in neu-

tral. When neutral is selected, the vehicle service

Operating Instructions, 3000 Series

brakes, parking brake, or emergency brake must be

applied. Selecting neutral does not apply vehicle

The Allison 3000 series transmission is electronically

brakes unless an auxiliary system to apply the park-

controlled and comes with a push-button shift control

ing brake is installed.

that provides five or six forward ranges and one re-

verse range. The push-button shift selector has R

This position is used when starting the engine and

(reverse), N (neutral), and D (drive) ranges, up and

for stationary operation. It is also used to shut down

down arrows, a mode button, and a digital display.

the vehicle when P (park) or PB (auto-apply parking

See Fig. 9.2.

brake) are not available on the shifter. In this case,

the parking brake must be applied.

R (Reverse)

Do not let the vehicle coast in neutral. If the vehicle

Press the R button to select reverse. The digital dis-

is allowed to coast in neutral, the engine brake will

play will show R when reverse is selected. Always

not work and the driver could lose control of the ve-

bring the vehicle to a complete stop and let the en-

hicle.

gine return to idle before shifting from a forward

range to reverse, or from reverse to a forward range.

D (Drive)

In the drive position, the transmission will initially go

NOTICE

into first range when drive is selected. As vehicle

speed increases, the transmission will upshift auto-

Extended idling in reverse may cause transmis-

matically through each available range up to fourth or

sion overheating and damage.

fifth range. As the vehicle slows, the transmission will

downshift automatically.

Do not idle in reverse for more than 5 minutes. Se-

lect neutral when time at idle exceeds 5 minutes.

When going downhill, downshift to a lower transmis-

sion range to increase engine braking and to help

NOTE: The shift into reverse may not succeed if

maintain control. The transmission has a feature to

a range inhibitor is active. When reverse is se-

prevent automatic upshifting above the lower range

lected, always be sure that R is not flashing.

9.3

Drivetrain

WARNING

Do not coast in neutral. Coasting in neutral can

cause an accident, possibly resulting in severe

personal injury or death.

Do not let the vehicle coast in neutral. If the vehicle

is allowed to coast in neutral, the engine brake will

not work and the driver could lose control of the ve-

hicle.

Always select neutral before turning off the engine.

D (Drive)

When the D button is pushed, the highest forward

range will appear in the display. The transmission will

07/27/2006

f610804

normally go into first range when drive is selected

1. Digital Display

3. Mode Indicator LED

(except for those units programmed to start in sec-

2. Mode Identification

4. Mode Button

ond range). As vehicle speed increases, the trans-

Label

mission will upshift automatically through each range.

As the vehicle slows, the transmission will downshift

Fig. 9.2, Push-Button Shift Selector

automatically.

N (Neutral)

NOTICE

WARNING

Do not idle in drive for more than 5 minutes. Ex-

tended idling in drive may cause transmission

When starting the engine, make sure that the ser-

overheating and damage. Always select neutral if

vice brakes are applied. Failure to apply the ser-

time at idle is longer than 5 minutes.

vice brakes may result in unexpected vehicle

movement, which could cause severe personal

NOTE: The shift into drive may not succeed if a

injury or death. Failure to apply the vehicle park-

range inhibitor is active. When drive is selected

ing brakes when the transmission is in neutral

always be sure that D is not flashing.

may allow the vehicle to move unexpectedly, pos-

sibly causing property damage or personal injury.

5, 4, 3, and 2 (Fifth, Fourth, Third, and

Press the N button to select neutral. The digital dis-

Second Ranges)

play will show N when neutral is selected. It is not

Occasionally, road conditions, load, or traffic condi-

necessary to press neutral before starting the ve-

tions will make it desirable to restrict automatic shift-

hicle. The electronic control unit (ECU) or TCM auto-

ing to a lower range. Lower ranges provide greater

matically places the transmission in neutral at start-

braking for going down grades. The lower the range,

up.

the greater the braking effect.

When neutral is selected, the vehicle service brakes,

Push the up or down arrows on the push-button shift

parking brake, or emergency brake must be applied.

selector to select individual forward ranges. The digi-

Selecting neutral does not apply vehicle brakes un-

tal display will show the selected range. When a

less an auxiliary system to apply the parking brake is

lower range is selected, the transmission may not

installed.

downshift until the vehicle speed or engine RPM (en-

gine governed speed) is reduced.

9.4

Drivetrain

Mode Button

WARNING

The MODE button starts a specialized input or output

When going downhill, use a combination of

function that has been previously programmed into

downshifting, braking, and other retarding de-

the ECU or TCM. Pressing the MODE button

vices to control vehicle speed and the engine’s

changes transmission operation for a specific func-

rated governed speed. Failure to do so could re-

tion.

duce vehicle braking, possibly causing loss of

vehicle control and resulting in personal injury or

Mode Indicator LED

property damage.

When the MODE button is pressed, the mode indica-

When going downhill, downshift to a lower transmis-

tor LED illuminates. A mode identification label, lo-

sion range to increase engine braking and to help

cated above the MODE button, identifies the function

maintain control. The transmission has a feature to

associated with a mode change.

prevent automatic upshifting above the lower range

selected. However, during downhill operation, if the

Digital Display

engine governed speed is exceeded in the lower

The dual digital display shows both the selected

range, the transmission may upshift to the next

range (SELECT) and actual range attained (MONI-

higher range.

TOR). The single digital display shows the selected

range.

1 (First Range)

Use the first range when pulling through mud or

Oil Level Sensor

deep snow, when maneuvering in tight spaces, or

Allison 3000 Series transmissions have an electronic

when driving up or down steep grades. First range

oil level sensor to read fluid level information. The

provides the vehicle with its maximum driving torque

fluid level diagnostic will display whether the oil level

and maximum engine braking effect. Push the down

is OK, too low, or too high. It will also display a de-

arrow until the first range appears on the display.

fault code and indicate if the preconditions (of receiv-

ing the fluid level information) are not met.

Up and Down Arrows

IMPORTANT: Maintain the proper fluid level at

When a lower range is desired, after D has been

all times. If the fluid level is too low, the con-

pressed, press the down arrow until the desired

range is shown on the display. Pressing the down

verter and clutch do not receive an adequate

arrow continuously causes the range position to con-

supply of fluid. If the level is too high, the trans-

tinue to go down until the button is released or the

mission may shift erratically or overheat.

lowest range is attained.

To access the oil level display mode, park the vehicle

When the transmission is in drive and the down

on a level surface, shift to N (neutral), apply the

arrow has the transmission in a lower range position,

parking brake, and idle the engine. Then simultane-

press the up arrow to shift to a higher selector posi-

ously press both the up and down arrows once. The

tion. Continuously pressing the up arrow causes the

oil level will display at the end of a two-minute count-

range position to continue to rise until the button is

down.

released or the highest available position is attained.

Diagnostic Codes

Continuously pressing the up or down arrows does

not override the transmission automatic shifting op-

Diagnostic codes are numerical indications relating to

eration. If a higher or lower position is selected, the

a malfunction in transmission operation. These codes

transmission continues shifting through the ranges

are logged in the TCM/ECU memory. The most se-

according to the vehicle operating characteristics

vere or most recent code is listed first. A maximum of

until the highest or lowest selection position is

five codes (numbered d1-d5) may be listed in

reached.

memory at one time. If the mode indicator LED is

illuminated, the displayed code is active. If it is not

illuminated, the displayed code is not active.

9.5

Drivetrain

NOTE: During normal operation, an illuminated

mode indicator LED signifies the specialized

mode operation is in use.

To enter diagnostics mode, first park the vehicle and

apply the parking brake. Then simultaneously press

both the up and down arrows twice.

Drive Axles, Detroit^™ and

Meritor^™

10/26/2001

f610596

For additional information regarding Meritor axles,

Fig. 9.3, Differential Lock Switch, Optional

visit the Meritor website at www.arvinmeritor.com.

switch begins to blink during normal operation,

Drive Axles With Differential Lock

when the switch has not been activated, an

error condition exists. Bring the vehicle to an

The optional driver-controlled differential lock should

authorized Freightliner service facility as soon

only be used under adverse road conditions where

as possible.

greater traction is needed. With the differential lock

on, the turning radius is increased and vehicle han-

When the differential lock switch is pressed, three

dling is affected. The red differential lock indicator

responses are possible: a normal response, a slow

light illuminates on the dash message center when

response, and an abnormal response.

the differential lock is engaged.

Normal Response: The LED in the switch blinks until

A differential lock provides maximum traction under

the axle has responded to the request to lock the

slippery conditions. When the differential lock is en-

wheels. At this point, the LED remains illuminated

gaged, the clutch collar completely locks the differen-

constantly. In normal operation, the wheels may lock

tial case, gearing, and axle shafts together, maximiz-

so quickly that the blinking of the switch is barely

ing the traction of both wheels and protecting against

noticeable.

spinout. Do not exceed 25 mph (40 km/h) when the

differential lock is engaged.

If operation of the switch is not possible for any rea-

son (ignition is turned off, vehicle is moving faster

Under normal traction conditions, do not use the dif-

than 25 mph, etc.), the LED will stop blinking and

ferential lock feature.

turn off.

Differential Lock Switch

Slow Response: If operation of the switch is slowed

for any reason (vehicle moving too fast, low air pres-

sure, etc.), the switch will continue to blink until the

NOTICE

wheels are able to lock. As in the normal response,

the LED remains illuminated when the differential

The differential lock should only be engaged

lock is engaged.

when the vehicle is stopped or moving slowly at

low throttle. This will prevent internal axle dam-

NOTE: If the vehicle is moving too fast, let up

age.

slightly on the accelerator. As the vehicle slows,

A two-position guarded rocker switch controls the

the wheels will lock.

differential lock. See Fig. 9.3. To lock the wheels to-

Abnormal Response: If the LED blinks for more than

gether, momentarily press the upper half of the

30 seconds, the lock mechanism may not be fully

switch. To unlock the wheels, press the upper half of

engaged/disengaged. Bring the vehicle to an autho-

the switch again.

rized Freightliner service facility for testing.

IMPORTANT: The differential lock rocker switch

is guarded to prevent unintentional switch acti-

vation. If the light emitting diode (LED) in the

9.6

Drivetrain

Differential Lock Operation

Fig. 9.4. Drive cautiously and do not exceed 25 mph

(40 km/h).

WARNING

Locking the wheels when the vehicle is traveling

down steep grades or when the wheels are slip-

ping could damage the differential and/or lead to

loss of vehicle control, causing personal injury

and property damage.

NOTICE

The differential lock should be engaged when the

02/09/96

f350079a

vehicle is stopped or moving at a low, constant

speed and the wheels are not spinning, slipping,

A. Turning Radius When the Differential Lock is

or losing traction. Engagement at high speed or

Engaged (understeer condition)

power can damage the axle(s).

B. Turning Radius When the Differential Lock is

Disengaged

Do not permit rear wheels to spin freely for more

than ten seconds when traction is lost. Shift into

Fig. 9.4, Turning Radii

lock to prevent damage to interaxle and main

To disengage the differential lock after leaving poor

differentials.

road conditions, press the upper half of the switch,

Lock the wheels only when the vehicle is standing

while maintaining vehicle speed. Let up momentarily

still or moving at very low speed, less than 5 mph (8

on the accelerator to allow the wheels to fully unlock,

km/h). Never lock the wheels when the vehicle is

then resume driving at normal speed.

traveling down steep grades or when the wheels are

NOTE: If the differential lock system is con-

slipping.

nected with the transmission in its low speed

NOTE: On some vehicles, the differential lock

range, shifting out of the low speed range will

system is connected through the low speed

also disengage the differential lock function. The

range of the transmission. If this system is used,

switch will blink until the wheels unlock, and

the transmission must be in the low speed

then go out.

range for the wheels to fully lock.

WARNING

A vehicle with locked wheels can still slip side-

ways, causing possible loss of vehicle control,

personal injury, and property damage.

Be especially careful when driving under slippery

conditions with the wheels locked. Though forward

traction is improved, the vehicle can still slip side-

ways.

If the vehicle is moving, maintain a constant vehicle

speed when the differential lock is turned on. Briefly

let up on the accelerator to relieve torque on the

gearing, allowing the wheels to lock completely.

When the wheels are fully locked, the turning radius

will increase because the vehicle understeers. See

9.7

Hydraulic and Air Brake Systems

Dual Air Brake System

A dual air brake system consists of two independent

air brake systems that use a single set of brake con-

trols. Each system has its own reservoir, plumbing,

and brake chambers. The primary air system oper-

ates the service brakes on the rear axle; the second-

ary air system operates the service brakes on the

front axle.

12/10/2003

f430360

Primary Air Brake System

1. Parking Brake Control Valve

Loss of air pressure in the primary air system causes

the rear service brakes to become inoperative. The

Fig. 10.1, Parking Brake Control Valve

front brakes will continue to be operated by the sec-

control, resulting in property damage or personal

ondary air system.

injury.

Secondary Air Brake System

Before driving the vehicle, secure all loose items in

the bus so that they will not fly forward during a full

Loss of air pressure in the secondary air system

brake application.

causes the front axle brakes to become inoperative.

The rear service brakes will continue to be operated

Parking Brake Interlock, Optional

by the primary air system.

Emergency Braking System

NOTICE

When air pressure is lost in one air system, the air

Do not continually push down on the parking

compressor will operate, but the air supply in the

brake control valve without pressing down on the

leaking system will not be replenished. There will be

service brake pedal. This will damage the safety

enough air in the working system to stop the vehicle

interlock.

safely. The dual air brake system thus provides

The service brakes and parking brakes have a safety

emergency braking capability. When the low air pres-

interlock that prevents the unintentional release of

sure warning light and emergency buzzer first come

the parking brake. These instructions need to be fol-

on, stop the vehicle immediately. Do not drive the

lowed for the appropriately equipped vehicle to re-

vehicle until the cause of the problem is corrected.

lease the parking brake interlock.

Parking Brakes

Parking Brake Interlock Release

Pulling out the yellow diamond-shaped knob (parking

1. Depress the brake pedal.

brake control valve) on the auxiliary dash panel ap-

plies the parking brakes (spring brakes). See

2. Push the parking brake control valve in.

Fig. 10.1.

Parking Brake and Ignition Key Release

Air Brake Operation

1. Turn the ignition key to the ON position.

2. Depress the brake pedal.

WARNING

3. Push the parking brake control valve in.

Do not operate the vehicle with the front brakes

Parking Brake, Ignition Key, Wheel Chair

backed off or disconnected. Backing off or dis-

connecting the front brakes will not improve ve-

Lift Interlock Release

hicle handling and may lead to loss of vehicle

1. Turn the ignition key to the ON position.

10.1

Hydraulic and Air Brake Systems

2. Check to see that the wheel chair lift is in the

3.3

Bring the vehicle to a safe stop and have

stowed position.

the air system repaired before continuing.

3. Confirm that the wheel chair lift switch is in the

4. During normal brake stops, depress the service

OFF position.

brake until braking action slows down the ve-

hicle. Increase or decrease the pressure on the

4. Depress the brake pedal.

pedal so that the vehicle comes to a smooth,

5. Push the parking brake control valve in.

safe stop.

IMPORTANT: In the event of a total loss of ser-

Transmission Shifter Interlock Release

vice brakes, use the parking brake control valve

1. If the vehicle is equipped with a wheel chair lift,

to bring the vehicle to a complete stop in the

make sure the lift is in the stowed position, and

safest location possible.

that the wheel chair lift switch is in the OFF posi-

tion.

5. When the forward speed of the vehicle has de-

creased almost to the idling speed of the engine,

2. Depress the service brake pedal to move the

shift the transmission to neutral. Apply the park-

vehicle shifter out of the park position.

ing brakes, if the vehicle is to be parked.

Operating the Brakes

NOTICE

To ensure safe operation and minimum brake wear,

follow the steps below when operating the brakes.

Do not use the spring parking brakes if the ser-

vice brakes are hot, such as after descending a

When the ignition switch is turned on, the low air

steep grade. Also, do not use the spring parking

pressure warning light (pressure circle icon) illu-

brakes during freezing temperatures if the ser-

minates and the emergency buzzer sounds.

vice brakes are wet. To do so could damage the

brakes if hot, or cause them to freeze during cold

1.1

Monitor the air pressure system by ob-

weather.

serving the low air pressure warning light,

the emergency buzzer, and both the pri-

If the brakes are wet, drive the vehicle in low

mary and secondary air pressure gauges.

gear and lightly apply the brakes to heat and dry

them. Allow hot brakes to cool before using the

1.2

The warning light and buzzer shut off

spring parking brakes. Always chock the tires.

when air pressure in both systems

reaches 65 to 75 psi (448 to 517 kPa).

Caging the Parking Brakes

Before driving the vehicle, continue to monitor

the air pressure system until the air compressor

WARNING

has built up a minimum pressure of 95 psi (655

kPa) in both the primary and secondary air sys-

Do not drive the vehicle with the parking brakes

tems.

caged. If the vehicle is driven with the parking

While driving, the low air pressure warning light

brakes caged, there would be no means of stop-

and buzzer come on if air pressure drops below

ping the vehicle if a complete loss of air pressure

65 to 75 psi (448 to 517 kPa) in either system.

occurred. This could result in serious personal

injury or vehicle damage.

3.1

If this happens, check the air system pres-

sure gauges to determine which system

To move a vehicle with insufficient system air pres-

has low air pressure.

sure, it is necessary to release the parking brake

springs. Do this by caging (manually releasing) the

3.2

Although vehicle speed can be reduced

parking brakes.

using the service brake, either the front or

rear service brakes will not be operating,

IMPORTANT: Before caging the parking brakes,

causing a longer stopping distance.

make the connection to a towing vehicle or

chock the tires.

10.2

Hydraulic and Air Brake Systems

After correcting the brake system problem, uncage

During normal braking stops, depress the brake

the parking brakes before resuming normal vehicle

pedal until braking action slows down the vehicle.

operation.

Increase or decrease the pressure on the pedal so

that the vehicle comes to a smooth, safe stop. Apply

the hand parking brake if the vehicle is to be parked.

Bosch Hydraulic Pin Slide

IMPORTANT: Make sure that the brake fluid in

Brakes

the master cylinder reservoirs is up to the level

General Information

of the ridge that surrounds the reservoir. See

Fig. 10.2. Use only DOT 3 or 4 brake fluid in

The Bosch hydraulic pin slide disc brake is a two-

the Bosch hydraulic pin slide brake system.

piston sliding caliper brake and is used at both the

front and rear wheel locations. Each pin slide caliper

disc brake wheel installation is made up of a caliper

Meritor Cam-Master® Q Plus

assembly, anchor plate assembly, and disc brake

Brakes

pads.

Cam-Master brakes are air-actuated, cam-operated,

Caliper Assembly

foundation brakes. The Q Plus increases service life

and mileage between relines by providing more lining

The caliper assembly has two hydraulic piston bores.

thickness. A specially designed S-cam and heavy-

The piston bores contain pistons, piston seals, and

duty shoe return spring allow additional shoe travel

piston boots. The caliper assembly attaches and

required to fully wear the thicker lining blocks. An

slides on sealed pins located in the anchor plate.

improved camshaft bushing contributes to longer ser-

The caliper housing is the main component of the

vice life.

caliper assembly. The material of the caliper housing

is ductile iron and has a protective coating to provide

additional environmental protection. The disc brake

Cam-Master Q Plus Operation

caliper housing straddles the rotor, the inner pad,

When the brake pedal is depressed, compressed air

and the outer pad.

enters the brake chamber, causing the diaphragm to

move a pushrod assembly.

Anchor Plate Assembly

The pushrod turns the slack adjuster and brake cam-

The anchor plate assembly includes lubricated float-

shaft. As the camshaft turns, the S-type cam head

ing guide pins sealed by rubber boots. The anchor

forces the brake shoes against the brake drum and

plate abutments are protected by stainless steel slip-

braking occurs.

pers.

When the brakes are released and air is exhausted

Disc Brake Pads

from the brake chamber, the actuator return spring

(within the brake chamber) and the brake shoe return

There are two pads per caliper assembly, and they

spring return the camshaft, brake shoes, slack ad-

are the inner and outer pads. The inner pad is lo-

juster, and pushrod to their released positions.

cated between the caliper piston and rotor. The outer

pad is located between the rotor and caliper housing

Meritor WABCO® Pneumatic

legs. The pads are made of friction material and a

stamped steel backing plate.

Antilock Braking System (ABS)

Operation

Pneumatic ABS is an electronic wheel speed moni-

toring and control system that works with the air

Before driving the vehicle, secure all loose items in

brake system. It passively monitors vehicle wheel

the bus so that they will not fly forward during a full

speed at all times, but controls wheel speed during

brake application. Check that the brake system warn-

an emergency or reduced-traction stop. In normal

ing light is off after releasing the hand brake. If the

braking applications, the standard air brake system is

warning light does not go off, correct the problem

in effect.

before continuing operation of the vehicle.

10.3

Hydraulic and Air Brake Systems

05/24/2012

f420477a

A. Fill level for brake fluid.

Fig. 10.2, Master Cylinder Reservoir

the existing traffic and road conditions. For example,

Pneumatic ABS Operation

the ABS cannot prevent an accident if the driver is

The Meritor WABCO ABS is a four-sensor system. It

speeding or following too closely on slippery road

combines one front-axle control channel with one

surfaces.

rear-axle control channel to form one control circuit.

Even if the ABS is partially or completely inoperative,

Example: The sensor and solenoid control valve at

normal braking ability is usually maintained.

the left front wheel form a control circuit with the sen-

IMPORTANT: If a solenoid control valve (or

sor and solenoid valve at the right rear axle.

combination solenoid control valve) is damaged

ABS includes signal-generating tone wheels and sen-

and inoperative, normal braking may be im-

sors located in the wheel hubs of each sensed axle.

paired.

The sensors transmit vehicle wheel speed informa-

tion to an electronic control unit.

Automatic Traction Control

IMPORTANT: For proper ABS operation, do not

Vehicles with electronic engines and ABS may have

change tire sizes. The sizes of the tires installed

Automatic Traction Control (ATC). On these vehicles,

during production are programmed into the elec-

the ATC system automatically limits wheel spin dur-

tronic control unit. Installing different sized tires

ing reduced-traction situations. In normal braking ap-

could result in a reduced braking force, leading

plications, the standard air brake system is in effect.

to longer stopping distances.

During reduced-traction situations, the ATC solenoid

During emergency or reduced traction stops, fully

valve controls air pressure to the modulator valves

depress the brake pedal until the vehicle comes to a

and they in turn increase, hold, or reduce pressure to

safe stop. Do not pump the brake pedal. With the

the appropriate brake chambers to provide better

brake pedal fully depressed, the ABS will control all

traction whenever wheel spin occurs.

wheels to provide steering control and a reduced

When the ATC system is in the NORMAL mode, it

braking distance.

will apply gentle braking to the spinning wheel, to

Although the ABS improves vehicle control during

feed power to the wheel(s) with better traction. If

emergency braking situations, the driver still has the

responsibility to change driving styles depending on

10.4

Hydraulic and Air Brake Systems

both wheels are spinning, the system will signal the

Automatic Slack Adjusters

engine to reduce power.

ATC may include a deep snow and mud option to

NOTICE

increase available traction on extra soft surfaces like

snow, mud, or gravel. If so equipped, a momentary

Manually adjusting an automatic slack adjuster to

contact rocker switch labeled ATC will be located on

bring the pushrod stroke within legal limits is

the dash. Pressing the switch will temporarily allow

likely masking a mechanical problem. Adjustment

more wheel spin. The activation of the deep snow

is not repairing. In fact, continual adjustment of

and mud option is indicated by a flashing WHEEL

automatic slack adjusters may result in prema-

SPIN lamp. Pressing the switch again will cycle the

ture wear of the adjuster itself. Further, the im-

system back to normal operation.

proper adjustment of some automatic slack ad-

justers may cause internal damage to the

NOTICE

adjuster, thereby preventing it from properly

functioning.

The deep snow and mud option is intended to be

Automatic slack adjusters should never be manually

used under specific slippery conditions that re-

adjusted except during routine maintenance of the

quire momentary increased wheel spin. Using

foundation brakes (e.g., replacing shoes), during

this option for an extended period of time may

slack adjuster installation, or in an emergency situa-

damage the vehicle brake system.

tion.

After the ignition switch is turned on, the ABS indica-

When the brake pushrod stroke exceeds the legal

tor light and the WHEEL SPIN indicator light illumi-

brake adjustment limit on a vehicle, there is likely a

nate for about three seconds. After three seconds,

mechanical problem with the foundation brake com-

the warning lights go out if all of the ABS compo-

ponents or the adjuster is improperly installed.

nents are working.

Visit a repair facility as soon as possible when

During vehicle operation, solid illumination of the

brakes equipped with automatic slack adjusters are

ABS light indicates a problem with the vehicle ABS.

determined to be out of adjustment.

Repair the ABS immediately to ensure full braking

capability.

Exhaust Brake

If equipped with ATC, an amber WHEEL SPIN indica-

tor light illuminates if one of the drive wheels spins

General Information

during acceleration. When the light illuminates, par-

An exhaust brake is an optional auxiliary braking sys-

tially release the throttle pedal to stop the spinning

tem that assists, but does not replace, the service

wheel. The light goes out when the wheel stops spin-

brake system. The driver can use the exhaust brake,

ning.

in combination with the accelerator and clutch pedal

If slippery road conditions continue, turn on the differ-

(if so equipped), to make maximum use of the ex-

ential lock switch. See Chapter 9 for axle switch in-

haust brake in off-highway and mountain driving as

structions.

well as in traffic or high-speed highway driving.

The exhaust brake is controlled by a dash-mounted

NOTICE

rocker switch, shown in Fig. 10.3, to help slow the

vehicle when the accelerator is released.

Do not turn the differential lock switch on while

the WHEEL SPIN indicator light is on. To do so

To turn the exhaust brake on, press on the upper

could damage the rear axle.

part of the rocker switch. When the exhaust brake

switch is on, an amber light emitting diode (LED) illu-

minates inside the switch. When the panel lights are

on, the EXHST BRK legend is backlit in green.

The exhaust brake is only active when engine speed

is between 1100 and 2700 rpm. Depressing the ac-

celerator deactivates the exhaust brake. The ABS

10.5

Hydraulic and Air Brake Systems

haust brake is applied. The following conditions

should exist if the brake is operating properly:

• A slight change in the sound of the engine may

be noticed when the exhaust brake is applied.

• Exhaust smoke should appear as normal.

• Engine temperature should remain in the nor-

mal operating range.

• Road speed usually decreases when the ex-

haust brake is applied during a descent. When

the vehicle is carrying a heavy load or the

11/28/2001

f610589

grade is extremely steep, the driver may need

to apply the service brakes occasionally.

Fig. 10.3, Exhaust Brake Switch

• Do not expect a retarding effect similar to sud-

system, when active, also deactivates the exhaust

den hard application of the service brakes. The

brake.

exhaust brake retards the vehicle with a

The exhaust brake is a butterfly valve mounted in the

smooth braking effect.

exhaust pipe. When the driver’s foot is not on the

• During a descent, the tachometer usually

accelerator pedal and the upper half of the exhaust

shows a drop in rpm depending on the grade

brake switch is pressed in, with the amber light on

and the vehicle load.

the switch illuminated, an air cylinder shuts the but-

terfly valve, which restricts the flow of exhaust gases

• Depending on the grade and vehicle load, you

and retards the engine. This retarding action is car-

may or may not feel the retarding force acting

ried through the engine and drivetrain, slowing the

against your body when the brake is applied.

vehicle and reducing the need for frequent service

The retarding force of the brake may not al-

brake applications.

ways be noticed, but it is actually preventing

the vehicle from going much faster.

Exhaust brakes are not intended for use as the pri-

mary braking system during vehicle operation.

Driving Downhill

Starting the Engine

While approaching a steep grade, make sure that the

upper half of the exhaust brake switch is pressed in,

Before starting the engine, make sure that the lower

with the amber LED illuminated. The exhaust brake

half of the exhaust brake switch is pressed in and

comes on as soon as you remove your foot from the

the amber light is not illuminated. Do not turn the ex-

accelerator pedal. While going down the grade, use

haust brake on until the engine has reached normal

a low enough gear to safely descend with a minimum

operating temperatures.

application of the service brakes. As a general guide-

line, use the same gear as you would to ascend the

Operating Characteristics

hill.

WARNING

NOTICE

Do not use the exhaust brake when driving on

Do not allow the engine to exceed its governed

slippery or low-traction road surfaces. Failure to

speed, or serious engine damage could result.

follow this precaution could result in a loss of

vehicle control and possible personal injury or

Apply the service brakes to reduce the engine rpm or

property damage.

make a slower descent by using a lower gear.

When you remove your foot from the accelerator,

and the upper half of the exhaust brake switch is

pressed in with the amber LED illuminated, the ex-

10.6

Saf-T-Liner C2 School Bus. Driver’s Manual (2012) - page 1