SsangYong Rexton. Service manual - part 511

ABS AND TCS  4E-3

SSANGYONG  Y200

TRACTION CONTROL SYSTEM
(TCS) DESCRIPTION

General Information

The traction control system (TCS) is a traction system
by means of brake intervention only, available in a low
speed range (< 60 kph).

It works on µ-split roads with sidewise different friction
coefficients.

The spinning driven wheel is braked and the drive
torque can be transferred to the wheel on the high-µ
side. During TCS active, the TCS information lamp is
blinking.

System Failure (EBD,

ABS or TCS are Not

Distinguished)

ABS Warning

Lamp

Ignition ON

ABS

Operation

TCS

Operation

TCS Passive Due to
Temperature Model

2 second on

for lamp

check

OFF

OFF

ON

OFF

TCS Info

Lamp

2 second on

for lamp

check

OFF

Blinking

(FLASHING)

OFF

ON

EBD Warning

Lamp

2 second on

for lamp

check

EBD

operation/OFF

OFF

ON

OFF

The temperature of the brakes is calculated by a
mathematical model and TCS is switched passive if
the calculated temperature is greater than a threshold
value (500 °C). TCS is permitted again, when the
calculated temperature is less than 350 °C.

Lamp Concepts

The system is equipped with an TCS information lamp,
which is blinking during TCS operation.

The activation of the EBD, TCS warning lamp and the
TCS info lamp is summarized in the following table:

SSANGYONG  Y200

4E-4  ABS AND TCS

Automatic Brake Differential (ABD)

ABD (Automatic Brake Differential) system is a type
of the TCS (ASR) system and substitutes the function
of the mechanical LSD (Limited Slip Differential)
system.

ABD system operates by controlling the braking forces
only under 60km/h.

TCS System Function

Traction control does not have any effect on the
operation of the vehicle until the control module detects
one or both of the front wheels rotating faster than the
rear wheels. At this time, the electronic brake control
module (EBCM) requests the powertrain control module
to reduce the amount of torque applied to the drive
wheels. The powertrain control module does this by
retarding timing and selectively turning off fuel
injectors. The EBCM applies the front brakes, thus
reducing torque to the front wheels. Once the front
wheel begins to rotate at the same speed as the rear
wheels, the system returns full control to the driver.
During traction control mode, if the brake is applied to
only one front wheel, most of the torque from the engine
is directed to the other front wheel which improves the
traction of the vehicle.

Pressure Modulation

Depending on the control deviation and the wheel
acceleration of the spinning wheel, pressure increase,
hold and decrease are made.

The pressure modulation is done with the conventional
control with the valves. Prime valve, inlet valve and
outlet valve according to the following table:

YAD4E020

Control Algorithm

The input signals for the control algorithm are the
filtered wheel speed signals from the ABS speed
processing.

With the speed difference of the driven wheels, the

control deviation is calculated.

If the control deviation exceeds a certain threshold
value, the wheel with the greater slip is braked actively.

The threshold value depends on the vehicle speed:

It is reduced with increasing vehicle speed down to a
constant value.

Prime Valve

Pilot Valve

Inlet Valve

Outlet Valve

Increase

Open

Closed

Open

Closed

Hold

Open

Closed

Closed

Closed

Decrease

Open

Closed

Closed

Open

V = Faster rear wheel speed - Slower rear wheel

speed

V = Vehicle speed

  * TCS is switched passive if the calculated temperature

is greater than a threshold value (500 °C).

•

TCS (ABD) Indicator turns on but TCS is permitted
again, when the calculated temperature is less than
350 °C.

Temperature Model

TCS operation is a high thermal load for the brakes.

To avoid any damages at the brakes, the disk
temperature is calculated with a mathematical model
for each driven wheel separately, After ignition on, the
calculation starts with 30 ° C and then three different
phases are evaluated separately and added:

TCS operation, braking and cooling phase.

If the temperature is higher than 500 °C, TCS is disabled
for this wheel.

It is permitted again, if the model has calculated down
the 350 °C.

Speed Range

TCS is available in the speed range 

≤

 60 kph.

Above 60 kph vehicle speed, TCS is passive.

It is possible to initiate TCS operation up to a vehicle
speed of 55 kph.

ABS AND TCS  4E-5

SSANGYONG  Y200

EBD (ELECTRONIC BRAKE
FORCE DISTRIBUTION) SYSTEM

System Description

As an add-on logic to the ABS base algorithm, EBD
works in a range in which the intervention thresholds
for ABS control are not reached yet.

EBD ensures that the rear wheels are sensitively
monitored for slip with respect to the front axle. If slip
is detected, the inlet valves for the rear wheels are
switched to pressure hold to prevent a further increase
in pressure at the rear-wheel breaks, thus electronically
reproducing a pressure-reduction function at the rear-
wheel brakes.

ABS features an enhanced algorithm which includes
control of the brake force distribution between the front
and rear axles. This is called Electronic Brake
Distribution. In an unloading car condition the brake
efficiency is comparable to the conventional system
but for a fully loaden vehicle the efficiency of the EBD
system is higher due to the better use of rear axle
braking capability.

The Benefits of EBD

•

Elimination of conventional proportioning valve EBD
utilizes the existing rear axle wheel speed sensor
to monitor rear wheel slip.

•

Based on many variables in algorithm a pressure
hold, increase and/or decrease pulsetrain may be
triggered at the rear wheels insuring vehicle
stability.

•

Vehicle approaches the ideal brake force
distribution (front to rear).

•

Constant brake force distribution during vehicle
lifetime.

•

EBD function is monitored via ABS safety logic
( c o n v e n t i o n a l   p r o p o r t i o n i n g   v a l v e s   a r e   n o t
monitorable).

•

“Keep alive” function.

Service Precautions

Observe the following general precautions during any
A B S /T CS   se rv ic e.   F a ilur e  t o  a d her e   t o   t h ese
precautions may result in ABS/TCS system damage.

1. Disconnect the EBCM harness connector before

performing the electric welding procedures.

2. Carefully note the routing of the ABS/TCS wiring

and wring components during removal. The ABS/
TCS components are extremely sensitive to EMI
(eletromagnetic interference). Proper mounting is
critical during component service.

3. Disconnect the EBCM connector with the ignition

OFF.

4. Do not hang the suspension components from the

wheel speed sensor cables. The cables may be
damaged.

5. Do not use petroleum based fluids in the master

cylinder. Do not use any containers previously used
for petroleum based fluids. Petroleum causes
swelling and distortion of the rubber components
in the hydraulic brake system, resulting in water
entering the system and lowering the fluid boiling
point.

YAD4E030

SSANGYONG  Y200

4E-6  ABS AND TCS

Electronic Brake-Force Distribution (EBD) Failure Matrix

Y

AD4E040