lock DAEWOO MATIZ 2003 Service Repair Manual

4F–8 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low
Pressure
Accumulator
Low Pressure
Accumulator
RRFL FR
RL
D17E206A
RR
Isolation ValveFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
ISOLATION MODE (PRESSURE MAINTAIN)
If the information from the wheel speed sensors indicate excessive wheel deceleration (imminent lockup), the first step
in the antilock sequence is to isolate the brake pressure being applied by the driver. The EBCM sends a voltage to the
coil to energize and close the isolation valves by pulling down on the armature. This prevents any additional fluid pres-
sure applied by the driver from reaching the wheel. Though each channel of the 4-channel system can operate inde-
pendently, once any front channel (brake) sees excessive deceleration, both front isolation valves are energized and
close thus, with the isolation valves closed, further unnecessary increases in the brake pressure will be prohibited.

ANTILOCK BRAKE SYSTEM 4F–9
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low
Pressure
Accumulator
Low Pressure
Accumulator
RRFL FR
RL
D17E207A
RR
Isolation ValveFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
DUMP MODE (PRESSURE DECREASE)
Once the pressure is isolated, it must be reduced to get the wheels rolling once again. This is accomplished by dump-
ing a portion of the brake fluid pressure into a low pressure accumulator (LPA).
The EBCM energizes the dump cartage coil(s) to open the dump cartridge, allowing fluid from the wheels to be
dumped into the LPA. This done with very short activation pulses opening and closing the dump cartridge passageway.
Brake pressure is lowered at the wheel and allows the wheel to begin spinning again.
The fluid taken from the wheels forces the spring back and is stored in the LPA. A portion of the fluid also primes the
pump. The dump cartridges are operated independently to control the deceleration of the wheel.

4F–10 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low Pressure
Accumulator
RRFL FR
RL
D17E208A
RR
Isolation Valve
Low
Pressure
AccumulatorFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve High Pressure Attenuator
REAPPLY MODE (PRESSURE INCREASE)
This reapply sequence is initiated to obtain optimum braking. The isolation valve is momentarily pumped open to allow
master cylinder and pump pressure to reach the brakes. This controlled pressure rise continues unitl the wheel is at
optimum brake output or until the brake pressure is brough up to the master cylinder output pressure.
If more pressure is required, more fluid is drawn from the master cylinder and applied to the brakes. The driver may
feel slight pedal pulsations, or pedal drop, this is normal and expected.
As fluid is reapplied to the wheel, they begin to slow down. If they approach imminent lockup again, the EBCM will
isolate, dump and reapply again. The control cycle (isolation, dump, reapply) occurs in milli-second intervals, allowing
seveal cycles to occur each second.
It is a much faster and more controlled way of “pumping the pedal”.

ANTILOCK BRAKE SYSTEM 4F–11
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low Pressure
Accumulator
RRFL FR
RL
D17E209A
RR
Isolation Valve
Low
Pressure
AccumulatorFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
PROPORTIONING FUNCTION
If the rear wheels lock formerly during braking, the vehicle may lose the stability. Therefore to prevent this, the ECM
processes the speed sensor signal and brake signal to determine when the rear wheels are tending to lock up. The
EBCM then actuates the rear wheel isolation valves to reduce the rear brake pressure and keep the wheels rolling.

4F–12 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
VISUAL IDENTIFICATION
EBCM CONNECTOR FACE VIEW
Terminal 9 is identified as they appear from the wire entry end of the harness connector.
EBCM Connector
D107E204
 
 Pin
 
 Signal Name
 
 Color
 
 Circuit
 2 ROUGH ROAD GRY/YEL Buffered Wheel Speed Signal : to ECM–55
(Sirius D3)
 
9
 
RRWSHI
 
BRN
 
Right Rear Wheel Speed High 
 10
 
 RRWSLO
 
 WHT
 
 Right Rear Wheel Speed Low
 11 SDLUART BRN/DK GRN Serial Data Link
 12 RFWSHI DK GRN/BLK Right Front Wheel Speed High
 13 RFWSLO BRN/DK GRN Right Front Wheel Speed Low
 14 LFWSHI DK BLU Left Front Wheel Speed High
 15 IGN RED/YEL Switched Ignition
 16 GND BLK Negative Battery Terminal 17 BATT RED Battery 18 BATT RED Battery 
 19
 
 GND
 
 BLK
 
 Negative Battery Terminal
 20 ABSWARN DK GRN/GRY ABS Warning Indicator
 22 LRWSHI BLK Left Rear Wheel Speed High
 23 LRWSLO RED Left Rear Wheel Speed Low
 24 BRAKESW YEL Brake Switch
 25 LFWSLO YEL Left Front Wheel Speed Low

ANTILOCK BRAKE SYSTEM 4F–13
DAEWOO M-150 BL2
COMPONENT LOCATOR
ABS
D17E401A
1. Hydraulic Modulator Unit
2. Electronic Brake Control Module (EBCM)
3. Bolt
4. Upper Mounting Bracket
5. Grommet6. Lower Mounting Bracket
7. Bracket Grommet
8. Rear Wheel Speed Sensor
9. Front Wheel Speed Sensor

4F–14 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
ABS (Cont’d)
D17E402A

ANTILOCK BRAKE SYSTEM 4F–15
DAEWOO M-150 BL2
BLANK

4F–16 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION AND PROCEDURES
D17E301A
DIAGNOSTIC TROUBLE CODE (DTC) 0354
LEFT FRONT WHEEL SPEED SENSOR CIRCUIT OPEN OR SHORTED
Circuit Description
As a toothed ring passes by the wheel speed sensor,
changes in the electromagnetic field cause the wheel
speed sensor to produce a sinusoidal (AC) voltage sig-
nal whose frequency is proportional to the wheel speed.
The magnitude of this signal is directly related to wheel
speed and the proximity of the wheel speed sensor to
the toothed ring often referred to as the air gap.
Diagnosis
This test detects a short to battery, ground, or open in
the left front wheel speed sensor circuit.
Cause(s)

The wheel speed circuit is open or shorted to the bat-
tery or ground.

There is a loose connection in the wheel speed cir-
cuit.

The wheel speed sensor resistance is very high.

The EBCM is malfunctioning.Fail Action
This is a critical operational fault. The ABS is disabled
and the ABS warning lamp is turned on. The proportion-
ing is operation.
Diagnostic Aids
An ‘‘intermittent’’ malfunction may be caused by a poor
connection, rubbed through wire insulation, or a wire
that is broken inside the insulation.
Thoroughly check any circuitry suspected of causing the
intermittent complaint. Look for backed out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, poor terminal to wiring connections,
or physical damage to the wiring harness.
Wheel speed sensor resistance will increase as the sen-
sor temperature increases.
When replacing a wheel speed sensor, inspect the sen-
sor terminals and harness connector for corrosion and/
or water intrusion. If evidence of corrosion or water

ANTILOCK BRAKE SYSTEM 4F–17
DAEWOO M-150 BL2
intrusion exists, replace the wheel speed sensor har-
ness. If replacing a wheel speed sensor harness, in-
spect the sensor terminals. If you find evidence of
corrosion or water intrusion, replace the wheel speed
sensor. Refer to “Front Wheel Speed Sensor” in this
section.Important: Wheel speed sensor intermittent malfunc-
tions may be difficult to locate. Take care not to disturb
any electrical connections before performing an indi-
cated step of this table. That will ensure that an intermit-
tent connection will not be corrected before the source
of the malfunction is found.
DTC 0354 – Left Front Wheel Speed Sensor Circuit Open or Shorted
 Step Action Value(s) Yes No
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
1. Turn the ignition switch to OFF.
2. Disconnect the EBCM harness connector from
the EBCM.
3. Use a digital voltmeter (DVM) to measure the
resistance between terminals 14 and 25 of
connector on the EBCM harness.
Is the resistance within the specified value? 
 
 
 
 
 
 
1.0 k
to
1.5 k

 
 
 
 
 
 
 
Go to Step 4
 
 
 
 
 
 
 
Go to Step 2
 
 
 
 
 
2
 
 
 
 
 
1. Disconnect the harness from the left front wheel
speed sensor.
2. Use a DVM to measure the resistance between
terminals 1 and 2 of the left front wheel speed
sensor connector.
Is the resistance within the specified value? 
 
 
 
 1.0 k
to
1.5 k

 
 
 
 
 Go to Step 4
 
 
 
 
 Go to Step 3
 
 3
 
 Replace the wheel speed sensor.
Is the repair complete?
 
 –
 
 System OK
 
 –
 
 
 
 
4
 
 
 
 
Use a DVM to measure the resistance between ter-
minal 14 of the EBCM harness connector, and termi-
nal 1 of the left front wheel speed sensor harness
connector.
Is the resistance within the specified value? 
 
 
 
less than 1

 
 
 
 
Go to Step 6
 
 
 
 
Go to Step 5 
 
 
 
5
 
 
 
 
1. Repair the high resistance in circuit DK BLU.
2. If the wheel speed sensor harness is damaged,
replace it.
Is the repair complete?
 
 
 
 
–
 
 
 
 System OK
 
 
 
 
–
 
 
 
 
6
 
 
 
 
Use a DVM to measure the resistance between ter-
minal 25 of the EBCM harness connector, and termi-
nal 2 of the left front wheel speed sensor harness
connector.
Is the resistance within the specified value? 
 
 
 less than 1

 
 
 
 Go to Step 8
 
 
 
 Go to Step 7 
 
 
 
7
 
 
 
 
1. Repair the high resistance in circuit YEL.
2. If the wheel speed sensor harness is damaged,
replace it.
Is the repair complete? 
 
 
 
–
 
 
 
 System OK
 
 
 
 
–
 
 8
 
 
Use a DVM to measure the resistance between
ground and terminal 14 of the EBCM connector.
Does the DVM show the specified value? 
 

 
 Go to Step 10
 
 Go to Step 9 
 9
 
 Repair the short to ground in circuit DK BLU.
Is the repair complete? 
 –
 
 System OK
 
 –