ignition DAEWOO LACETTI 2004 Service Repair Manual

4F – 20IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
13Repair the contact at the I/P cluster connector termi-
nal A1.
Is the repair complete?–System OK–
14Check the wiring harnesses and connectors in cir-
cuit PPL/WHT from the I/P cluster terminal A1 to ter-
minal 21 of the EBCM connector.
Does the ohmmeter show the specified value?Go to Step 15Go to Step 16
15Repair the open or high resistance found.
Is the repair complete?–System OK–
16Check for continuity between terminal 19 of the ABS
connector and ground G106.
Does the ground connection match the specified val-
ue?0 WGo to Step 17Go to Step 18
17Replace the ABS unit.
Is the repair complete?–System OK–
18Repair the continuity problem between terminal 19
of the EBCM connector and ground G106.
Is the repair complete?–System OK–
191. Turn the ignition switch to LOCK.
2. Check fuse F4 in the I/P fuse block.
Is this fuse blown?–Go to Step 20Go to Step 21
20Replace fuse F4.
Is the repair complete?–System OK–
21Check fuse EF5 in the engine fuse block.
Is this fuse blown?–Go to Step 22Go to Step 23
22Replace fuse EF5.
Is the repair complete?–System OK–
23Measure the voltage at terminal 2 of the ignition
switch connector by backprobing.
Is the voltage within the specified value?11–14 vGo to Step 25Go to Step 24
241. Check circuit RED between terminal 4 of C105
at the engine fuse block and terminal 2 of the
ignition switch for continuity.
2. Repair any open or high resistance found.
Is the repair complete?–System OK–
251. Turn the ignition switch to ON.
2. Backprobe terminal 4 (PNK) of the ignition
switch connector.
Is the voltage within the specified value?11–14 vGo to Step 27Go to Step 26
26Replace the ignition switch.
Is the repair complete?–System OK–
271. Turn the ignition switch to LOCK.
2. Check circuit PNK from terminal 4 of the igni-
tion switch to fuse F4 in the I/P fuse block.
Does the ohmmeter show the specified value?Go to Step 28Go to Step 29

4F – 22IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
SELF–DIAGNOSTICS
Important : The electronic brake control module (EBCM)
turns the valve relay off when a diagnostic trouble code
(DTC) is set. The scan tool will indicate that the valve relay
is off when it is used to monitor the data list. This is normal
and should not be considered a malfunction.
Important : For safety reasons it is recommended that the
vehicle not be driven with test equipment connected. Ex-
ception : for testing of wheel speeds provided the test reg-
ulations are met.
The EBCM performs system self–diagnostics and can de-
tect and often isolate system malfunctions. When it de-
tects a malfunction, the EBCM sets a DTC that represents
the malfunction, turns ON the ABS and/or the EBD indica-
tors in most instances, and may disable the ABS and/or
the EBD functions as necessary for the duration of the igni-
tion cycle.
Once each ignition cycle, the EBCM performs an automat-
ic test when the vehicle speed > 6 km/h and the brake ped-
al is not actuated or when the vehicle speed > 15 km/h and
the brake pedal is actuated. In the course of this test, the
system cycles each valve solenoid and the pump motor,
along with the necessary relays, to check component op-
eration. If the EBCM detects any malfunctions, it will set
a DTC as described above.
DISPLAYING DTCS
Tools Required
Scan Tool
DTCs can be read through the use of the scan tool.
CLEARING DTCS
Tools Required
Scan Tool
The diagnostic trouble codes (DTCs) in the electronic
brake control module (EBCM) memory are erased:S Use the scan tool ”Clear DTCs” selection.
The method is detailed below. Be sure to verify proper sys-
tem operation and absence of DTCs when the clearing
procedure is completed.
The EBCM will not permit DTC clearing until all DTCs have
been displayed. Also, DTCs cannot be cleared by discon-
necting the EBCM, disconnecting the battery cables, or
turning the ignition switch to LOCK.
Scan Tool Method
The scan tool can clear ABS system DTCs using the mass
storage cartridge.
1. Install the scan tool and the mass storage cartridge.
2. Select ”Fault Memory.”
3. Select ”Clear Fault Memory.”
Clearing the fault memory cannot reset a valve relay which
was shut down when the fault was recognized. Changes
are possible only after the fault has been eliminated and
the next ignition cycle has begun.
INTERMITTENTS AND POOR
CONNECTIONS
As with most electronic systems, intermittent malfunctions
may be difficult to diagnose accurately. The following is a
method to try to isolate an intermittent malfunction, espe-
cially in wheel speed circuitry.
If an ABS malfunction occurs, the ABS indicator will illumi-
nate during the ignition cycle in which the malfunction was
detected. If it is an intermittent problem which seems to
have corrected itself (ABS indicator off), a history DTC will
be stored. Also stored will be the history data of the DTC
at the time the malfunction occurred. Use the scan tool
modular diagnostic system to read ABS history data.
Most intermittents are caused by faulty electrical connec-
tions or wiring, although a sticking relay or solenoid can oc-
casionally be at fault.

4F – 24IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
DTC C0035 – Left Front Wheel Speed Sensor Circuit Malfunction
StepActionValue(s)YesNo
1Examine the wheel speed sensor.
Are there any signs of physical damage?–Go to Step 3Go to Step 2
21. Turn the ignition switch to LOCK.
2. Disconnect the left front wheel speed sensor
connector.
3. Use a digital voltmeter (DVM) to measure the
resistance between the sensor terminals.
Is the resistance within the specified value at
approximately 25°C (77°F)?1280–1920 WGo to Step 4Go to Step 3
3Replace the wheel speed sensor.
Is the repair complete?–System OK–
41. Switch the DVM to the AC millivolt range.
2. Measure the voltage output of between the
wheel speed sensor terminals while rotating
the wheel about 1 revolution every 2 seconds.
Is the output within the specified value?
120 vGo to Step 6Go to Step 5
5Replace the speed sensor or the toothed wheel as
required.
Is the repair complete?–System OK–
61. Disconnect the harness from the EBCM.
2. Connect a DVM between ground and one ter-
minal of the wheel speed connector.
3. Turn the ignition to ON.
4. Repeat the above test for the other terminal of
the wheel speed connector.
Is the voltage for either of these terminals within the
specified value?> 1 vGo to Step 7Go to Step 8
7Repair the short to voltage in the affected circuit.
Is the repair complete?–System OK–
81. Turn the ignition switch to LOCK.
2. Measure the resistance to ground from termi-
nal 6 at the harness EBCM connector.
3. Measure the resistance to ground from termi-
nal 7 at the harness EBCM connector.
Is the resistance at either circuit less than the speci-
fied value?Go to Step 9Go to Step 10
9Repair the short to ground in the affected circuit.
Is the repair complete?–System OK–
101. Measure the resistance between terminal 6 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the WHT wire.
2. Measure the resistance between terminal 7 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the ORN wire.
Is the resistance on either circuit within the specified
value?> 5 WGo to Step 11Go to Step 12

ANTILOCK BRAKE SYSTEM 4F – 27
DAEWOO V–121 BL4
DTC C0040 – Right Front Wheel Speed Sensor Circuit Malfunction
StepActionValue(s)YesNo
1Examine the wheel speed sensor.
Are there any signs of physical damage?–Go to Step 3Go to Step 2
21. Turn the ignition switch to LOCK.
2. Disconnect the right front wheel speed sensor
connector.
3. Use a digital voltmeter (DVM) to measure the
resistance between the sensor terminals.
Is the resistance within the specified value at
approximately 25°C (77°F)?1280–1920 WGo to Step 4Go to Step 3
3Replace the wheel speed sensor.
Is the repair complete?–System OK–
41. Switch the DVM to the AC millivolt range.
2. Measure the voltage output of between the
wheel speed sensor terminals while rotating
the wheel about 1 revolution every 2 seconds.
Is the output within the specified value?
120 vGo to Step 6Go to Step 5
5Replace the speed sensor or the toothed wheel as
required.
Is the repair complete?–System OK–
61. Disconnect the harness from the EBCM.
2. Connect a DVM between ground and one ter-
minal of the wheel speed connector.
3. Turn the ignition to ON.
4. Repeat the above test for the other terminal of
the wheel speed connector.
Is the voltage for either of these terminals within the
specified value?> 1 vGo to Step 7Go to Step 8
7Repair the short to voltage in the affected circuit.
Is the repair complete?–System OK–
81. Turn the ignition switch to LOCK.
2. Measure the resistance to ground from termi-
nal 4 at the harness EBCM connector.
3. Measure the resistance to ground from termi-
nal 5 at the harness EBCM connector.
Is the resistance at either circuit less than the speci-
fied value?Go to Step 9Go to Step 10
9Repair the short to ground in the affected circuit.
Is the repair complete?–System OK–
101. Measure the resistance between terminal 4 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the WHT wire.
2. Measure the resistance between terminal 5 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the GRY wire.
Is the resistance on either circuit within the specified
value?> 5 WGo to Step 11Go to Step 12

4F – 30IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
DTC C0045 – Left Rear Wheel Speed Sensor Circuit Malfunction
StepActionValue(s)YesNo
1Examine the wheel speed sensor.
Are there any signs of physical damage?–Go to Step 3Go to Step 2
21. Turn the ignition switch to LOCK.
2. Disconnect the left rear wheel speed sensor
connector.
3. Use a digital voltmeter (DVM) to measure the
resistance between the sensor terminals.
Is the resistance within the specified value at
approximately 25°C (77°F)?1280–1920 WGo to Step 4Go to Step 3
3Replace the wheel speed sensor.
Is the repair complete?–System OK–
41. Switch the DVM to the AC millivolt range.
2. Measure the voltage output of between the
wheel speed sensor terminals while rotating
the wheel about 1 revolution every 2 seconds.
Is the output within the specified value?
120 vGo to Step 6Go to Step 5
5Replace the speed sensor or the toothed wheel as
required.
Is the repair complete?–System OK–
61. Disconnect the harness from the EBCM.
2. Connect a DVM between ground and one ter-
minal of the wheel speed connector.
3. Turn the ignition to ON.
4. Repeat the above test for the other terminal of
the wheel speed connector.
Is the voltage for either of these terminals within the
specified value?> 1 vGo to Step 7Go to Step 8
7Repair the short to voltage in the affected circuit.
Is the repair complete?–System OK–
81. Turn the ignition switch to LOCK.
2. Measure the resistance to ground from termi-
nal 8 at the harness EBCM connector.
3. Measure the resistance to ground from termi-
nal 9 at the harness EBCM connector.
Is the resistance at either circuit less than the speci-
fied value?Go to Step 9Go to Step 10
9Repair the short to ground in the affected circuit.
Is the repair complete?–System OK–
101. Measure the resistance between terminal 8 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the RED wire.
2. Measure the resistance between terminal 9 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the BLK wire.
Is the resistance on either circuit within the specified
value?> 5 WGo to Step 11Go to Step 12

ANTILOCK BRAKE SYSTEM 4F – 33
DAEWOO V–121 BL4
DTC C0050 – Right Rear Wheel Speed Sensor Circuit Malfunction
StepActionValue(s)YesNo
1Examine the wheel speed sensor.
Are there any signs of physical damage?–Go to Step 3Go to Step 2
21. Turn the ignition switch to LOCK.
2. Disconnect the left rear wheel speed sensor
connector.
3. Use a digital voltmeter (DVM) to measure the
resistance between the sensor terminals.
Is the resistance within the specified value at
approximately 25°C (77°F)?1280–1920 WGo to Step 4Go to Step 3
3Replace the wheel speed sensor.
Is the repair complete?–System OK–
41. Switch the DVM to the AC millivolt range.
2. Measure the voltage output of between the
wheel speed sensor terminals while rotating
the wheel about 1 revolution every 2 seconds.
Is the output within the specified value?
120 vGo to Step 6Go to Step 5
5Replace the speed sensor or the toothed wheel as
required.
Is the repair complete?–System OK–
61. Disconnect the harness from the EBCM.
2. Connect a DVM between ground and one ter-
minal of the wheel speed connector.
3. Turn the ignition to ON.
4. Repeat the above test for the other terminal of
the wheel speed connector.
Is the voltage for either of these terminals within the
specified value?> 1 vGo to Step 7Go to Step 8
7Repair the short to voltage in the affected circuit.
Is the repair complete?–System OK–
81. Turn the ignition switch to LOCK.
2. Measure the resistance to ground from termi-
nal 1 at the harness EBCM connector.
3. Measure the resistance to ground from termi-
nal 2 at the harness EBCM connector.
Is the resistance at either circuit less than the speci-
fied value?Go to Step 9Go to Step 10
9Repair the short to ground in the affected circuit.
Is the repair complete?–System OK–
101. Measure the resistance between terminal 1 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the WHT wire.
2. Measure the resistance between terminal 2 at
the harness EBCM connector and the harness
wheel speed sensor connector terminal con-
nected to the GRY wire.
Is the resistance on either circuit within the specified
value?> 5 WGo to Step 11Go to Step 12

ANTILOCK BRAKE SYSTEM 4F – 35
DAEWOO V–121 BL4
J3B14F09
DLC
(Data Link
Connector)
EBCM
DK BLUDK BLU
BLK/WHTC202
C110
11 2
1912 19
G106
DIAGNOSTIC TROUBLE CODE (DTC) C0060/C0065
LEFT FRONT INLET AND OUTLET VALVE SOLENOID
FAULT
Circuit Description
The solenoid valve coil circuits are supplied with power
from the battery when the valve relay is energized.
Switched ground is provided by the electronic brake con-
trol module (EBCM) to each coil.
Diagnosis
This procedure checks whether the left front inlet and out-
let valves are functioning.
Cause(s)
S A valve has failed.S A solenoid coil is open or shorted.
Fail Action
ABS is disabled, and the ABS warning lamp is turned ON
for the remainder of the ignition cycle. EBD is disabled. If
the failure is intermittent, the EBCM will enable the system
at the next ignition cycle and set a history DTC.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This step begins the test of the inlet valve.
3. This step tests the outlet valve.

4F – 36IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
DTC C0060/C0065 – Left Front Inlet and Outlet Valve Solenoid
Fault
StepActionValue(s)YesNo
11. Raise and suitably support the vehicle at the
corner being tested.
2. Turn the ignition switch to ON.
3. Install the scan tool to the Data Link Connector
(DLC) and select “Wheel front left” to begin the
solenoid tests at that wheel. This will test both
the inlet and the outlet valves.
4. When the scan tool indicates ”Pressure hold,”
depress and hold the brake pedal until the end
of the test.
5. Have an assistant attempt to rotate the wheel.
Can the wheel be rotated?–Go to Step 2Go to Step 6
21. Maintain pressure on the brake pedal.
2. When the scan tool indicates ”Pressure in-
crease,” have an assistant attempt to rotate the
wheel again.
Can the wheel be rotated now?–Go to Step 6Go to Step 3
31. Maintain pressure on the brake pedal.
2. When the scan tool indicates ”Pressure release
on,” have an assistant attempt to rotate the
wheel again.
Can the wheel be rotated?–Go to Step 4Go to Step 6
41. Release brake pedal pressure when the scan
tool indicates ”Pressure release off.”
2. Clear all DTCs.
3. Road test the vehicle.
Does the DTC set again?–Go to Step 6Go to Step 5
51. Check the wiring harness and connector termi-
nals for an intermittent problem.
2. Repair any problem found.
Is the repair complete?–System OK–
6Replace the ABS unit.
Is the repair complete?–System OK–

ANTILOCK BRAKE SYSTEM 4F – 37
DAEWOO V–121 BL4
J3B14F09
DLC
(Data Link
Connector)
EBCM
DK BLUDK BLU
BLK/WHTC202
C110
11 2
1912 19
G106
DIAGNOSTIC TROUBLE CODE (DTC) C0070/C0075
RIGHT FRONT INLET AND OUTLET VALVE SOLENOID
FAULT
Circuit Description
The solenoid valve coil circuits are supplied with power
from the battery when the valve relay is energized.
Switched ground is provided by the electronic brake con-
trol module (EBCM) to each coil.
Diagnosis
This procedure checks whether the right front inlet and
outlet valves are functioning.
Cause(s)
S A solenoid coil is open or shorted.Fail Action
ABS is disabled, and the ABS warning lamp is turned ON
for the remainder of the ignition cycle. EBD is disabled. If
the failure is intermittent, the EBCM will enable the system
at the next ignition cycle and set a history DTC.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This begins the test of the inlet valve.
3. This tests the outlet valve.

4F – 38IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
DTC C0070/C0075 – Right Front Inlet and Outlet Valve Solenoid
Fault
StepActionValue(s)YesNo
11. Raise and suitably support the vehicle at the
corner being tested.
2. Turn the ignition switch to ON.
3. Install the scan tool to the Data Link Connector
(DLC) and select ”Wheel front right” to begin
the solenoid tests at that wheel. This will test
both the inlet and the outlet valves.
4. When the scan tool indicates ”Pressure hold,”
depress and hold the brake pedal until the end
of the test.
5. Have an assistant attempt to rotate the wheel.
Can the wheel be rotated?–Go to Step 2Go to Step 6
21. Maintain pressure on the brake pedal.
2. When the scan tool indicates ”Pressure in-
crease,” have an assistant attempt to rotate the
wheel again.
Can the wheel be rotated now?–Go to Step 6Go to Step 3
31. Maintain pressure on the brake pedal.
2. When the scan tool indicates ”Pressure release
on,” have an assistant attempt to rotate the
wheel again.
Can the wheel be rotated?–Go to Step 4Go to Step 6
41. Release brake pedal pressure when the scan
tool indicates ”Pressure release off.”
2. Clear all DTCs.
3. Road test the vehicle.
Does the DTC set again?–Go to Step 6Go to Step 5
51. Check the wiring harness and connector termi-
nals for an intermittent problem.
2. Repair any problem found.
Is the repair complete?–System OK–
6Replace the ABS unit.
Is the repair complete?–System OK–