SsangYong Musso. Manual - part 450

ANTILOCK BRAKE SYSTEM 4F-7

ABD SYSTEM DESCRIPTION

General:

The Automatic Brake Differential Lock (ABD) is a traction system by means of brake intervention only, available in
a low speed range (< 60kph).

It workes on

-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-

side.

During ABD active, the ABD information lamp is blinking.

The temperature of the brakes is calculated by a mathematical model and ABD is switched passive if the calculated
temperature is greater than a threshold value(500

C).

ABD is permitted again, when the calculated temperature is less than 350

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.

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. ASV, USV, EV and AV according
the the following table:

Speed Range:

ABD is available in the speed range

≤

60 kph.

Above 60 kph vehicle speed, ABD is passive.

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

Increase

Open

ASV

Decrease

Hold

Closed

Open

Closed

USV

Speed difference driven wheels [kph]

ABD operation

Vehicle
speed
[kph]

4F-8 ANTILOCK BRAKE SYSTEM

Temperature Model:

ABD 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:

ABD operation, braking and coling phase.

If the temperature is highter than 500

C, ABD is disabled for this wheel.

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

Lamp Concepts:

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

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

Ignition

ABS

Operation

ABD

Operation

System failure

(EBD,ABS or ABD are

not distinguished)

ABD passive due

to temperature

model

ABS warning

lamp

ABD info

lamp

EBD warning

lamp

2s on for lamp

check

2s on for lamp

check

2s on for lamp

check

OFF

EBD operation

/ OFF

OFF

Dlinking

(Flashing)

OFF

ANTILOCK BRAKE SYSTEM 4F-9

SELF DIAGNOSIS

ABS, ABS/ABD 5.3

Initialization

1. Turn the ignition switch to "ON" position.

2. Using a service connector, ground the No.13 terminal of

diagnosis socket and No.1 ground terminal for 3 - 4 seconds.

Notice

If it is over 5 seconds, initialization will not be performed.

3. After completing the initialization, ABS warning lamp will be

turned on until the ignition switch is turned to "OFF" position.

Output of Fault Code

1. Normal : 1 pulse (normal code 01)

2. Abnormal : 1 pulse (fault code)

Notice

If appeared initial fault code and above 2 differnt fault

code, perform again initialization.

Fault code will be output the numbers of fault code with

a interval of 1 second.(turn on : 0.75 sec., turn off : 0.25
sec.)

Fault Code Elimination

After repairing the defect parts, eliminate the fault from ECU.

1. Ground the diagnosis No.13 terminal to No.1 ground terminal

for over 5 seconds.

2. Turn the igniotion switch to "OFF" position.

Notice

If not eliminate the fault code, the code will be maintained.

Check and find the other defect parts with performing

the imitialization again, if the fault code will be output,
repair the defect parts completely.

4F-10 ANTILOCK BRAKE SYSTEM

Diagnosis the Flash Code

[Ex]

Time Differences of Normal Code 01 : TW1<T<Te<TW2

Time Differences of Fault Code 15 : TW1<T<Te<TW2

Time Characteristics

1. Initialization

Tba < 5.0 sec.

Tba 1.8 - 2.2 sec.

2. Output of Fault Code

TW1 = 1.8 - 2.2 sec.

TW2 = 1.8 - 2.2 sec.

T = 0.75 sec., Te

≥

0.25 sec.

3. Elimination of Fault Code

Tb1 = 5.0 sec.

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