DAEWOO LACETTI 2004 Service Repair Manual

4F – 50IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
J3B14F11
Left Front Left RearRight Front
Right Rear
EBCM
BRN LT
BLU1
2
6
7
PPL
GRYGRY GRY
YEL
C111
WHT 1
12
2
44
55WHT WHT1
1 2
43
89
Wheel Speed Sensors
BRNBRN DK
BLUBLK
BLK REDC302
C110 WHT
WHT1 2
2
110
33
DIAGNOSTIC TROUBLE CODE (DTC) C0245
WHEEL SPEED SENSOR FREQUENCY ERROR
Circuit Description
The toothed wheel generates a voltage pulse as it moves
past the wheel speed sensor. Each tooth–gap–tooth se-
ries on the wheel generates the pulses. The electronic
brake control module (EBCM) uses the frequency of these
pulses to determine wheel speed. The voltage generated
depends on the air gap between the wheel speed sensor
and the toothed wheel, and on the wheel speed.
Diagnosis
This DTC will set when the EBCM cannot identify which
wheel speed sensor is causing the malfunction. It is nec-
essary to check all wheel speed sensors and associated
wiring to determine the cause of the DTC.
Cause(s)
S Incorrect number of teeth on the toothed wheel.
S Damaged or broken teeth on the toothed wheel.
S Discontinuity or short in wheel speed sensor wiring.
Fail Action
Antilock brake system (ABS) action is disabled and the
ABS warning lamp is ON.Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This step begins the examination of the front wheel
speed sensors.
3. This step checks for a problem with one of the front
toothed rings.
5. This step checks the front wheel speed sensors.
7. This step checks for shorts in a front wheel speed
sensor harness.
9. This step checks for opens in a front wheel speed
sensor harness.
11. This step begins a check of the rear wheel speed
sensors.
13. This step checks for a problem with one of the rear
toothed rings.
15. This step checks the rear wheel speed sensors.
17. This step checks for shorts in a rear wheel speed
sensor harness.
19. This step checks for opens in a rear wheel speed
sensor harness.

ANTILOCK BRAKE SYSTEM 4F – 51
DAEWOO V–121 BL4
Diagnostic Aids
DTC C0245 may be set by running the scan tool auto test
if the throttle angle readings are not updating while in the
data list mode. If this is the case, clear the DTCs, discon-
nect the scan tool, and road test the vehicle to at least 12
km/h (7 mph) to see if the DTC resets.
Check the toothed wheels for any large grooves, gouges,
marks, etc. that might influence the tooth’s signal at the
wheel speed sensor. Also check for a buildup of foreignmaterial in the gaps between teeth in the toothed wheel,
this material may cause this malfunction.
A badly worn hub/bearing assembly may cause this mal-
function. The wheel speed sensor–to–toothed wheel air
gap may change excessively due to bearing play.
If an improper rear hub assembly or front outer constant
velocity joint is installed, one with a toothed wheel contain-
ing the incorrect number of teeth, this DTC can set. Be
sure that the front and the rear toothed wheel have 47 and
29 teeth.
DTC C0245 – Wheel Speed Sensor Frequency Error
StepActionValue(s)YesNo
1Visually inspect the wiring for the front wheel speed
sensors.
Is there any damage?–Go to Step 2Go to Step 3
2Check that the correct outer constant velocity (CV)
joints are installed on the vehicle. The front speed
rings have 47 teeth and the rear speed rings have 29
theeth.
Is the repair complete?–System OK–
3Check fuse EF2 in the engine fuse block.
Is one of these incorrect?–Go to Step 4Go to Step 5
4Replace the incorrect outer CV joint with the proper
unit.
Is the repair complete?–System OK–
51. Disconnect the wheel speed sensor harnesses
from the wheel speed sensor connectors.
2. Measure the wheel speed sensor resistance at
the wheel speed sensor connector terminals.
Does the resistance fall within the specified values
for both wheel speed sensors?1280–1920 WGo to Step 7Go to Step 6
6Replace the faulty wheel speed sensor.
Is the repair complete?–System OK–
71. Disconnect ABS control module connector.
2. Check each wheel speed sensor harness for a
short circuit between its wires with a digital
ohmmeter attached to the two terminals at the
harness side of the wheel speed sensor con-
nector.
3. Also check each wheel speed sensor harness
wire for a short to ground from the connector
terminals.
Is there any short circuit in either wheel speed sen-
sor harness?–Go to Step 8Go to Step 9
8Repair the short circuit in the wiring or from a wiring
harness to ground.
Is the repair complete?–System OK–

4F – 52IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
9Check the continuity of the wiring in both front wheel
speed sensor circuits between the ABS connector
and the wheel speed sensor wheel speed sensor
connector on each side of the vehicle.
1. The left side uses terminals 6 and 7 at the ABS
connector.
2. The right side uses terminals 4 and 5 at the
ABS connector.
Is continuity good for both harnesses?–Go to Step 11Go to Step 10
10Repair the discontinuity found in the front wheel
speed sensor harness.
Is the repair complete?–System OK–
111. Visually inspect the wiring for the rear wheel
speed sensors.
2. Check that the wheel speed sensors are prop-
erly mounted and that the retaining bolts are
properly tightened.
Is there any damage?–Go to Step 12Go to Step 13
12Repair or replace components as required.
Is the repair complete?–System OK–
13Remove each wheel speed sensor from the rear
knuckles and inspect the toothed ring through the
wheel speed sensor mounting holes.
1. Check for any damaged or missing teeth.
2. Check that the ring is properly positioned under
the wheel speed sensor.
Is there any damage or other fault with either speed
ring?–Go to Step 14Go to Step 15
14Replace the rear wheel hub with the proper unit.
Is the repair complete?–System OK–
151. Disconnect the rear wheel speed sensor har-
nesses from the wheel speed sensor connec-
tors.
2. Measure the wheel speed sensor resistance at
the wheel speed sensor connector terminals.
Does the resistance fall within the specified values
for both wheel speed sensors?1280–1920 WGo to Step 17Go to Step 16
16Replace the faulty wheel speed sensor.
Is the repair complete?–System OK–
171. The ABS control module connector should still
be disconnected. Disconnect it now if it is not.
2. Check each wheel speed sensor harness for a
short circuit between its wires with a digital
ohmmeter attached to the two terminals at the
harness side of the wheel speed sensor con-
nector.
3. Also check each wheel speed sensor harness
wire for a short to ground from the connector
terminals.
Is there any short circuit in either wheel speed sen-
sor harness?–Go to Step 18Go to Step 19

ANTILOCK BRAKE SYSTEM 4F – 53
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
18Repair the short circuit in the wiring or from a wire to
ground.
Is the repair complete?–System OK–
19Check the continuity of the wiring in both rear wheel
speed sensor circuits between the ABS connector
and the wheel speed sensor wheel speed sensor
connector on each side of the vehicle.
1. The left side uses terminals 8 and 9 at the ABS
connector.
2. The right side uses terminals 1 and 3 at the
ABS connector.
Is continuity good for both harnesses?–Go to Step 21Go to Step 20
20Repair the discontinuity found in the rear wheel
speed sensor wheel speed sensor harness or con-
nector C110.
Is the repair complete?–System OK–
21Replace the ABS unit.
Is the repair complete?–System OK–

4F – 54IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
J3B14F04
60A Ef230A Ef5
2
42
C107 C105
2
C110
G106
A19
A13 A1 A14
C110 C202
C202WHT LT GRN
DK
GRN LT GRN/
BLK
BLK
DK BLUDK BLU
PPL/WHT
PPL/WHT ABS
TCS Parking
Brake
Hot at all times
RED REDRED/WHT
Ignition
Switch
RED
RED
I/P Cluster
EBCM8
20
22 2216 41
1211
18 1621
1
C107
10A F410AF11
32 31
43
6 62 C201
C201 C201C201
C110 C202
Hot in Run and Start
30
4
1711
C202
15
B15
DLC
(Data Link
Connector)12
G106
BLK/WHTOil Feeding
Connector
”2” Ter.
BRNBRN BRN
BRN PNK PNK PNK
19J1
59B1
ONStart Lock
Acc
IG1
19
DIAGNOSTIC TROUBLE CODE (DTC) C0550
ABS CONTROL MODULE INTERNAL FAULT
Circuit Description
The ABS control module performs various diagnostic
checks on itself. If it finds a problem, it sets DTC C0550.
Diagnosis
This procedure checks whether there is a poor ground
connection for the electronic brake control module
(EBCM).
Cause(s)
S A connector terminal is corroded.
S The EBCM is malfunctioning.
Fail Action
ABS is disabled, and the ABS warning lamp is turned ON.EBD is disabled. If the failure is intermittent, the control
module will enable the system at the next ignition cycle
and will store a history DTC C0550.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
3. This step begins the testing for a poor voltage or
ground connection.
Diagnostic Aids
It is very important to perform a thorough inspection of the
wiring and the connectors. Failure to inspect the wiring
and the connectors carefully and completely may result in
misdiagnosis, causing part replacement with the reap-
pearance of the malfunction.

ANTILOCK BRAKE SYSTEM 4F – 55
DAEWOO V–121 BL4
DTC C0550 – ABS Control Module Internal Fault
StepActionValue(s)YesNo
1Use the scan tool to determine if any other DTCs are
set.
Are other DTCs set?–Go to the
tables for the
other DTCsGo to Step 2
2Clear all DTCs and road test the vehicle.
Does DTC C0550 set again?–Go to Step 4Go to Step 3
31. Check all wiring harness connectors and termi-
nals, especially those at the EBCM, for any
condition that could cause an intermittent.
2. Repair any problems found.
Is the repair complete?–System OK–
41. Turn the ignition switch to OFF.
2. Disconnect EBCM connector J1.
3. Turn the ignition switch to ON.
4. Measure the voltage between ground and ter-
minals 15, 17, and 18 of the EBCM harness
connector J1.
Is the voltage equal to the specified value?11–14 vGo to Step 6Go to Step 5
51. Check the voltage supply and the ground con-
nections to the EBCM.
2. Repair any open or high resistance found.
Is the repair complete?–System OK–
6Check the EBCM connector J1 for any ineffective
terminals.
Are there any problems?–Go to Step 7Go to Step 8
7Repair any connector problem found.
Is the repair complete?–System OK–
8Clear all DTCs and road test the vehicle.
Does DTC C0550 set again?–Go to Step 9System OK
9Replace the ABS unit.
Is the repair complete?–System OK–

4F – 56IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
J3B14F04
60A Ef230A Ef5
2
42
C107 C105
2
C110
G106
A19
A13 A1 A14
C110 C202
C202WHT LT GRN
DK
GRN LT GRN/
BLK
BLK
DK BLUDK BLU
PPL/WHT
PPL/WHT ABS
TCS Parking
Brake
Hot at all times
RED REDRED/WHT
Ignition
Switch
RED
RED
I/P Cluster
EBCM8
20
22 2216 41
1211
18 1621
1
C107
10A F410AF11
32 31
43
6 62 C201
C201 C201C201
C110 C202
Hot in Run and Start
30
4
1711
C202
15
B15
DLC
(Data Link
Connector)12
G106
BLK/WHTOil Feeding
Connector
”2” Ter.
BRNBRN BRN
BRN PNK PNK PNK
19J1
59B1
ONStart Lock
Acc
IG1
19
DIAGNOSTIC TROUBLE CODE (DTC) C0800
LOW VOLTAGE FAULT
Circuit Description
Proper operation of the electronic brake control module
(EBCM) requires a certain minimum voltage. The EBCM
monitors the ignition feed circuit to determine if the voltage
falls below a minimum level.
Diagnosis
This test checks for battery output, proper grounding,
blown fuses, faulty ignition switch, and problems in the cir-
cuitry.
Cause(s)
S The battery is defective.
S There is a defective ground connection.
S A connector is damaged.
S A wire is broken or shorted.
S A fuse is blown.
S The ignition switch is malfunctioning.
Fail Action
ABS action is disabled during the period of low voltage,and the ABS warning lamp is ON for the remainder of the
ignition cycle. If the failure is intermittent, the EBCM will
enable the system at the next ignition cycle and set a histo-
ry DTC C0800.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This step determines whether there is voltage at
the battery and at the high current source.
7. This step checks for voltage at the ignition 1
source.
11. This step begins the check for voltage at the EBCM
end of the ABS harness.
15. This step checks for a defective ground connection.
16. This is a check for a defective EBCM connector.
Diagnostic Aids
It is very important to perform a thorough inspection of the
wiring and the connectors. Failure to do so may result in
misdiagnosis, causing part replacement with a reappear-
ance of the malfunction.

ANTILOCK BRAKE SYSTEM 4F – 57
DAEWOO V–121 BL4
DTC C0800 – Low Voltage Fault
StepActionValue(s)YesNo
1Check the voltage at the battery.
Is the voltage within the specified value?11–14 vGo to Step 3Go to Step 2
2Charge or replace the battery as required.
Is the repair complete?–System OK–
3Check fuse EF2 in the engine fuse block.
Is the fuse blown?–Go to Step 4Go to Step 7
41. Replace fuse EF2.
2. Turn the ignition to ON.
Does the fuse blow again?–Go to Step 5Go to Step 6
51. Turn the ignition to OFF.
2. Trace the RED wires in the ABS wiring harness
from terminal 1 of C107 at the engine fuse
block to terminals 17 and 18 of the EBCM con-
nector.
3. Repair any short circuit found along this path.
Is the repair complete?–System OK–
61. Turn the ignition switch to OFF.
2. Install the scan tool.
3. Clear all DTCs.
4. Road test the vehicle.
Does DTC C0800 reset?–System OK–
7Check fuse F11 in the I/P fuse block.
Is the fuse blown?–Go to Step 8Go to Step 11
81. Replace fuse F11.
2. Turn the ignition to ON.
Does the fuse blow again?–Go to Step 9Go to Step 10
91. Turn the ignition to OFF.
2. Trace the BRN wire from fuse F11 to terminal
43 of connector C201, from terminal 62 of con-
nector C202 to terminal 6 of connector C110,
and from there to terminal 15 of the EBCM
connector.
3. Repair any short circuit found along this path.
Is the repair complete?–System OK–
101. Turn the ignition switch to OFF.
2. Install the scan tool.
3. Clear all DTCs.
4. Road test the vehicle.
Does DTC C0800 reset?–System OK–
111. Disconnect the EBCM connector from the
EBCM.
2. Turn the ignition to ON.
3. Check for the presence of battery voltage be-
tween ground and terminal 17, and between
ground and terminal 18.
Is the voltage within the specified value?11–14 vGo to Step 13Go to Step 12

4F – 58IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
121. Turn the ignition switch to OFF.
2. Trace the orange wires between terminals 17
and 18 of the EBCM connector to terminal 1 of
connector C107 at the engine fuse block.
3. Repair the open in this circuit.
Is the repair complete?–System OK–
13Check the voltage between ground and terminal 15
of the EBCM connector.
Is the voltage within the specified value?11–14 vGo to Step 17Go to Step 14
141. Turn the ignition switch to OFF.
2. Check fuse EF5 in the engine fuse block.
Is the fuse blown?–Go to Step 15Go to Step 16
15Replace fuse EF5.
Is the repair complete?–System OK–
161. Examine circuit BRN between terminal 15 of
the EBCM connector to terminal 6 of connector
C110 to terminal 62 of C202, to F11 in the I/P
fuse block.
2. Examine the PNK wire from the I/P fuse block
to terminal 4 (IG1) of the ignition switch.
3. Examine the RED wire from terminal 2 (B1) of
the ignition switch to terminal 59 of connector
C202 to terminal 4 of connector C105 at the
engine fuse block.
4. Repair the open in the wiring or possibly bad
connector terminal, or defective ignition switch.
Is the repair complete?–System OK–
171. Turn the ignition to OFF.
2. Check the resistance between ground and ter-
minals 16 and 19 of the ABS harness EBCM
connector.
Is the resistance equal to the specified value?0 WGo to Step 18Go to Step 20
18Examine terminals 15, 16, 17, 18, and 19 of the
EBCM connector.
Is there a defective terminal?–Go to Step 19Go to Step 21
19Repair the defective terminal or replace the connec-
tor or wiring harness as required.
Is the repair complete?–System OK–
20Repair the defective ground connection.
Is the repair complete?–System OK–
211. Install the scan tool.
2. Clear all DTCs.
3. Road test the vehicle.
Does DTC C0800 set again?–Go to Step 23Go to Step 22
221. Examine the wiring harness and connectors for
causes of intermittent problems.
2. Repair any intermittent problem found.
Is the repair complete?–System OK–
23Replace the ABS unit.
Is the repair complete?–System OK–

ANTILOCK BRAKE SYSTEM 4F – 59
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) C0931
OVERHEATED
DTC Description
The brake can be overheated when the TCS controls the
brake system to reduce the velocity of driving wheel. At
this moment, the EBCM calculates the brake application
time and frequency and shows the warning sign of over
heated driving wheel to the driver.Cause(s)
S EBCM show the driving wheel temperature over
400 °C.
Fail Action
TCS dose not functioning when the DTC C0931 is de-
tected.