1998 SSANGYONG MUSSO Workshop Repair Manual

4F-6 ANTILOCK BRAKE SYSTEM
ABS,ABS/ABD
COMPONENT LOCATOR
1 ABS Hydraulic Unit
2 ABS/ABD Hydraulic Unit
3 Diagnosis Socket
4 Front Wheel Speed Sensor
5 Front Impulse Ring6 Rear Wheel Speed Sensor
7 Rear Impulse Ring
8 ABS Warning Indicator Light
9 TCS Indicator Light
1 0 ABS/ABD ECU

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 m-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- m 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°C.
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 Open Open ASVDecrease Hold
Closed Closed Closed
Closed Closed Open
Open Closed Closed USV
EV
AV
Speed difference driven wheels [kph]
18
6
1260ABD 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°C.
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
ONABS
OperationABD
OperationSystem failure
(EBD,ABS or ABD are
not distinguished)ABD passive due
to temperature
model
ABS warning
lamp
ABD info
lamp
EBD warning
lamp2s on for lamp
check
2s on for lamp
check
2s on for lamp
checkOFF
EBD operation
/ OFFOFFOFF
Dlinking
(Flashing)
OFFON
OFF
ONOFF
OFF
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
lIf appeared initial fault code and above 2 differnt fault
code, perform again initialization.
lFault 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
lIf not eliminate the fault code, the code will be maintained.
lCheck 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]
lTime Differences of Normal Code 01 : TW1 lTime Differences of Fault Code 15 : TW1 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 ³ 0.25 sec.
3. Elimination of Fault Code
Tb1 = 5.0 sec.

ANTILOCK BRAKE SYSTEM 4F-11
ABS, ABS/ABD 5.0
Initializing
1. Set the ignition switch n “ON” position.
2. Connect the No.1 terminal (Ground) and the No.13 (ABS)
from diagnosis socket located in E/G room by use of service
connector for 3 - 4 seconds and initialize the flash code.
Notice
Be careful not to connect over 5 seconds.
3. ABS indicator warning light continuously comes on until the
ignition switch is “OFF”.
Dignosis Table
1. When the system is normal
lOne pulse (normal code 01) indicates.
2. When the system is abnormal
lOne pulse (defect code) indicates.
Notice
Repeat the initializing procedure when checking the
defect code Defect code is indicated once for 1 sec (light
on : 0.75 sec, light off : 0.25 sec).
Removal the Defect Code
1. Repair the defect code and remove the memorized defect
code in the ECU.
2. Connect the No. 13 terminal (ABS) from diagnosis socket
and No. 1 terminal (ground) for over 5 seconds.
3. Set the ignition switch in the “OFF” position.
Notice
lDefect code will be memorized in ECU unless the defect
code is not removed.
lRepeat the initializing procedure and check the other
defects.

4F-12 ANTILOCK BRAKE SYSTEM
Diagnosis the Flash Code
[ex]
lTime differences of nromal code 01 : TW1 lTime differences of fault code 15 : TW1 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 ³ 0.25 sec.
3. Elimination of fault code
Tb1 = 5.0 sec.

ANTILOCK BRAKE SYSTEM 4F-13
DEFECT CODES
Description
-
Replace the ECU
lCheck resistance of the wheel speed sensor :
1.280KW - 1.920KW
lCheck wire for ground and open.
lReplace the sensor.
lCheck resistance of the wheel speed sensor :
1.280KW - 1.920KW
lCheck wire for ground and open.
lReplace the sensor.
lCheck resistance of the wheel speed sensor :
1.280KW - 1.920KW
lCheck wire for ground and open.
lReplace the sensor.
lCheck resistance of the wheel speed sensor :
1.280KW - 1.920KW
lCheck wire for ground and open.
lReplace the sensor.
lCheck wire for ground and open.
lCheck connection of the wheel speed sensor connec-
tor and ECU side connector.
lMeasure air gap between wheel teeth and wheel speed
sensor and check installation of wheel tooth.
(Standard air gap : 0.35 - 1.60 mm)
lCheck output voltage of the sensor by rotating the
wheel 1/2 - 1 revolution per second and shaking sen-
sor wire.
- When measured by multi - meter (AC) :
output voltage > 70 mV
- When measured in oscilloscope :
output voltage ³ 120 mV/P-P
lReplace the sensor.
lCheck wire for ground and open.
lCheck connection of the wheel speed sensor. con-
nector and ECU side connector.
lMeasure the air gap between wheel teeth and wheel
speed sensor and check installation of wheel tooth.
(Standard air gap : 0.35 - 1.60 mm)
lCheck output voltage of the sensor by rotating the
wheel 1/2 - 1 revolution per second and shaking sen-
sor wire. Defect Code
01
02
03
04
05
06
07
08Application
Normal
Defective ECU
Front/left Wheel Speed
Sensor (Wire)
Front/right Wheel Speed
Sensor (Wire)
Rear/left Wheel Speed
Sensor (Wire)
Rear/right Wheel Speed
Sensor (Wire)
Front/left Wheel Speed
Sensor (Signal)
Front/right Wheel Speed
Sensor (Signal)