Page 569 of 1184

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”.
Page 570 of 1184
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.
Page 571 of 1184
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
Page 572 of 1184
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
Page 573 of 1184
4F–14 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
ABS (Cont’d)
D17E402A
Page 574 of 1184
ANTILOCK BRAKE SYSTEM 4F–15
DAEWOO M-150 BL2
BLANK
Page 575 of 1184

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
Page 576 of 1184

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
–