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Audi A4. Body repair manual - part 64

Cruise control On Board Diagnostic (OBD)

Gasoline engines with electronically-

operated throttle valve only

Testing cruise control system

control module.

The engine should be idling.

Except for the control lever, there are no system

components for the cruise control system. All

functions are carried out by the engine control

module.

Initiating "Read Measuring Value Block" scan

tool function 08

Rapid data transfer

HELP

Indicated on display

Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block"

function 08.

Cruise control On Board Diagnostic (OBD)

Rapid data transfer

Indicated on display

08 - Read Measuring Value Block

- Press -Q- button to confirm input.

Read Measuring Value Block

HELP

Indicated on display

Input display group number XXX

- Enter display group number 066.

The engine should be idling.

- Press -Q- button to confirm input.

The measured value block which has been selected will appear in the

standard format.

Display group overview

Display group

Display fields

number

066

Actual vehicle speed km/h

Switch positions of brake, clutch and cruise

control (open or closed)

Desired vehicle speed km/h

Control lever switch positions

Cruise control On Board Diagnostic (OBD)

Display group 066

Read Measuring Value Block 66

Indicated on display

km/h

X X X X

km/h

X X X X

Control lever switch positions

0 0 0 0 = Cruise control off (switch engaged)

0 0 1 1 = Cruise control on

0 0 0 1 = Cruise control off before engagement position

0 1 1 1 = Fix button pushed

1 0 1 1 = Record button pulled

Desired vehicle speed (speed last saved is displayed until):

Cruise control is switched off at control lever, i.e. switch is engaged on "OFF" or

Engine is stopped.

Switch positions for brakes, clutch and cruise control released.

1 0 0 0 = Cruise control released

1 0 1 1 = Brake applied (brake pedal switch)

1 1 0 0 = Clutch applied

Actual vehicle speed

Cruise control On Board Diagnostic (OBD)

Read Measuring Value Block 66

Indicated on display

0 km/h

1 0 0 0

0km/h

0 0 0 0

Checking displays in display fields 2 and 4

Read Measuring Value Block 66

Display check, display field 2

0 km/h

1 0 0 0

0km/h

0 0 0 0

Test conditions

Display field 2

Cruise control released (activated)

1000

Brake applied (brake pedal switch)

1011

Clutch applied

1100

If the nominal value in display field 2 for "cruise control released" (1000) is

not attained:

- Check engine control module identification.

Repair Manual, Fuel Injection & Ignition, Repair Group 01

- If "G" is not displayed after component name, cruise control is not

Cruise control On Board Diagnostic (OBD)

Read Measuring Value Block 66

Display check, display field 4

0 km/h

1 0 0 0

0km/h

0 0 0 0

Test conditions

Display field

Switch -B- in "OFF" (AUS) position

0000

Switch -B- to "ON" (EIN) position

0011

Memory set, switch -B- to "OFF" (AUS) before

0001

engaging

Button -A- pressed, "SET" (FIX)

0111

Switch -B- to "RES" (AUFN)

1011

If the nominal values in display field 4 are not attained even though switch

-B- is set to "ON" (0011):

- Connect VAG1598/31 breakout box to engine control module harness

Cruise control On Board Diagnostic (OBD)

Activating cruise control

- Connect VAG1551 scan tool (VAG1552)

module.

Rapid data transfer

HELP

Indicated on display

Select function XX

- Press button -1- twice for "Login procedure" function 11 and press -Q-

button to confirm input.

HELP

Indicated on display

Input code number XXXXX

- Input code 11463 and press -Q- button to confirm input.

Deactivate cruise control

Rapid data transfer

HELP

Indicated on display

Select function XX

- Press button -1- twice for "Login procedure" function and press -Q-

button to confirm input.

HELP

Indicated on display

Input code number XXXXX

Cruise control On Board Diagnostic (OBD)

Cruise control On Board Diagnostic (OBD)

Testing wiring and components using

VAG1598/31 breakout box

Notes:

VAG1598/31 breakout box is designed to be

connected to the engine control module

harness and to the engine control module

simultaneously.

The effect of this design is that the electronic

engine controls remain fully functional while the

breakout box is connected (for e.g. measuring

signal strengths while the engine is running).

Look in the respective test descriptions to see if

it is necessary to connect the engine control

module to the breakout box.

Use multimeter (Fluke 83 or equivalent) or

VAG1715 Multimeter in addition to VAG1527B

voltage tester.

Always use test leads from VW1594 connector

test kit when connecting test equipment to

VAG1598/31 breakout box.

Once the engine control module has been

reconnected, adapt the engine control module

Cruise control On Board Diagnostic (OBD)

Repair Manual, Fuel Injection & Ignition,

Repair Group 24

CAUTION!

Before connecting the test leads, switch the

test equipment to the appropriate measuring

range and observe the test requirements to

prevent damage to electronic components.

Cruise control On Board Diagnostic (OBD)

- Switch ignition off.

- Remove control module protective housing

cover.

- Using screwdriver, carefully pry off retainer (arrow).

- Release and disconnect harness connectors from control module.

- Connect VAG1598/31 breakout box to harness connector. Connect

breakout box Ground clip (not visible in illustration) to battery negative

terminal. Check respective test descriptions to see if it is necessary to

connect engine control module to breakout box.

- Perform tests as described in respective repair instructions.

Cruise control On Board Diagnostic (OBD)

- Disconnect 15-pin harness connector for cruise

control switch, clutch vacuum vent valve switch -

F36- and to brake vacuum vent valve switch -

F47- for cruise control.

- Check the following connections for a short to

positive, short to Ground (GND) or an open

circuit:

Gasoline engine: 2.7 liter/184 kW V6 twin-

turbo

Terminals on 15-pin

VAG1598/31 breakout

harness connector

box, socket

- If necessary, repair open or short circuit.

Cruise control On Board Diagnostic (OBD)

Terminals on 15-pin

VAG1598/31

harness connector

breakout box,

socket

to clutch vacuum vent valve

switch -F36- (terminal 1)

to brake vacuum vent valve

switch -F47- for cruise

control (terminal 2)

to brake vacuum vent valve

switch -F47- for cruise

control (terminal 4)

- If necessary, repair open or short circuit.

Battery

The battery is one of the most important

electrical components in the vehicle. If it

functions properly, the battery will make a

significant contribution to customer satisfaction.

To ensure a long service life, the battery must be

checked, serviced and maintained as described

in this section.

In addition to starting the engine, the battery has

additional functions as a buffer and supplier of

electrical power for the entire vehicle electrical

system.

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