1997 SSANGYONG KORANDO wheel

ABS AND TCS 4F-3
SSANGYONG MY2002
GENERAL DESCRIPTION AND SYSTEM OPERATION
BASIC KNOWLEDGE REQUIRED
Before using this section, it is important that you have
a basic knowledge of the following items. Without this
knowledge, it will be difficult to use the diagnostic
procedures contained in this section.
•Basic Electrical Circuits - You should understand
the basic theory of electricity and know the meaning
of voltage, current (amps), and resistance (ohms).
You should understand what happens in a circuit
with an open or shorted wire. You should be able to
read and understand a wiring diagram.
Use of Circuit Testing Tools - You should know
how to use a test light and how to bypass
components to test circuits using fused jumper
wires. You should be familiar with a digital
multimeter. You should be able to measure voltage,
resistance, and current, and be familiar with the
controls and how to use them correctly.
ABS SYSTEM COMPONENTS
The ABS 5.3 Antilock Braking System (ABS) consists
of a conventional hydraulic brake system plus antilock
components. The conventional brake system includes
a vacuum booster, master cylinder, front disc brakes,
rear disc brakes, interconnecting hydraulic brake pipes
and hoses, brake fluid level switch and the BRAKE
indicator.
The ABS components include a hydraulic unit, an elec-
tronic brake control module (EBCM), two system fuses,
four wheel speed sensors (one at each wheel), intercon-
necting wiring, the ABS indicator, the EBD indicator
and the TCS indicator. See “ABS Component Locator”
in this section for the general layout of this system.
The hydraulic unit with the attached EBCM is located
between the surge tank and the bulkhead on the left
side of the vehicle.
The basic hydraulic unit configuration consists of hy-
draulic check valves, two solenoid valves for each
wheel, a hydraulic pump, and two accumulators. The
hydraulic unit controls hydraulic pressure to the front
calipers and rear calipers by modulating hydraulic
pressure to prevent wheel lockup.
Units equipped with TCS add two more valves for each
drive wheel for the purpose of applying the brake to a
wheel that is slipping. This is done with pressure from
the hydraulic pump in the unit. There is also a TCS
indicator lamp on the instrument panel to alert the driver
to the fact that the TCS system is active. The
components identified in the drawing are those added
to the basic ABS 5.3 system to provide traction control.
Nothing in the hydraulic unit or the EBCM is serviceable.
In the event of any failure, the entire ABS unit withattached EBCM must be replaced. For more
information, refer to “Base Braking Mode” and
“Antilock Braking Mode” in this section.
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 (< 60kph).
It workes 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.
The temperature of the brakes is calculated by a mathe-
matical model and TCS is switched passive if the calcu-
lated temperature is greater than a threshold value (500
°C).
TCS is permitted again, when the calculated tempera-
ture 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.
KAA4F010

SSANGYONG MY2002
4F-4 ABS AND TCS
Pressure Modulation
Depending on the control deviation and the wheel accel-
eration 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, pilot valve, inlet
valve and outlet valve according to the following table:
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.
Prime Valve
Pilot Valve
Inlet Valve
Outlet Valve
Increase
Open
Closed
Open
ClosedHold
Open
Closed
Closed
ClosedDecrease
Open
Closed
Closed
Open
System Failure (EBD,
ABS or TCS are Not
Distinguished)
ABS Warning
LampIgnition ONABS
OperationTCS
OperationTCS Passive Due to
Temperature Model
2 second on
for lamp
checkOFF OFF ON OFF
TCS Info
Lamp2 second on
for lamp
checkOFFBlinking
(FLASHING)OFF ON
EBD Warning
Lamp2 second on
for lamp
checkEBD
operation/OFFOFF ON OFF
Temperature Model
TCS operation is a high thermal load for the brakes.
To avoid any damages at the brakes, the disk tempera-
ture 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 coling phase.
If the temperature is highter than 500°C, TCS is dis-
abled for this wheel.
It is permitted again, if the model has calculated down
the 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 issummarized in thefollowing table:

ABS AND TCS 4F-5
SSANGYONG MY2002
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
(conventional proportioning valves are not
monitorable).
“Keep alive” function.Service Precautions
Observe the following general precautions during any
ABS/TCS service. Failure to adhere to these
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.
KAA4F020

SSANGYONG MY2002
4F-8 ABS AND TCS
1 Master Cylinder
2 Hydraulic Modulator
3 Damper
4 Pump
5 Pump Motor
HYDRAULIC CIRCUIT
ABS 5.3
Pressure Increased
KAA4F040
6 Accumulator
7 Inlet Valve for Each Wheel
8 Outlet Valve for Each Wheel
9 Front Wheel
10 Rear Wheel

ABS AND TCS 4F-9
SSANGYONG MY2002
Pressure Maintained
1 Master Cylinder
2 Hydraulic Modulator
3 Damper
4 Pump
5 Pump Motor
KAA4F050
6 Accumulator
7 Inlet Valve for Each Wheel
8 Outlet Valve for Each Wheel
9 Front Wheel
10 Rear Wheel

SSANGYONG MY2002
4F-10 ABS AND TCS
Pressure Maintained
1 Master Cylinder
2 Hydraulic Modulator
3 Damper
4 Pump
5 Pump Motor
KAA4F060
6 Accumulator
7 Inlet Valve for Each Wheel
8 Outlet Valve for Each Wheel
9 Front Wheel
10 Rear Wheel

ABS AND TCS 4F-11
SSANGYONG MY2002
1 Master Cylinder
2 Hydraulic Modulator
3 Damper
4 Pump
5 Pump Motor
6 Accumulator
7 Inlet Valve for Each Wheel
ABS/TCS 5.3
Pressure Increased
KAA4F070
8 Outlet Valve for Each Wheel
9 Wheel
10 Prime Valve
11 Pilot Valve
12 Check Valve
13 ISD (Integrated Suction Damper)

SSANGYONG MY2002
4F-12 ABS AND TCS
Pressure Maintained
1 Master Cylinder
2 Hydraulic Modulator
3 Damper
4 Pump
5 Pump Motor
6 Accumulator
7 Inlet Valve for Each Wheel
KAA4F080
8 Outlet Valve for Each Wheel
9 Wheel
10 Prime Valve
11 Pilot Valve
12 Check Valve
13 ISD (Integrated Suction Damper)