SECTION : 4C
POWER BOOSTER
TABLE OF CONTENTS
SPECIFICATIONS4C–1 . . . . . . . . . . . . . . . . . . . . . . . . . .
Fasrener Tightening Specifications 4C–1. . . . . . . . . .
DIAGNOSIS4C–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Booster Functional Check 4C–1. . . . . . . . . . . .
MAINTENANCE AND REPAIR4C–2 . . . . . . . . . . . . . . . ON–VEHICLE SERVICE 4C–2. . . . . . . . . . . . . . . . . . . . .
Vacuum Hose 4C–2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Booster Assembly 4C–2. . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION4C–6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Booster 4C–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS
FASRENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Booster–to–Bracket Nuts (Right–Hand Drive)2216–
Booster–to–Dash Panel Nut (Left–Hand
Drive)2216–
Booster Hex Nut and Pushrod Clevis1813–
Brake Line Fittings1612–
DIAGNOSIS
POWER BOOSTER FUNCTIONAL
CHECK
1. With the engine stopped, eliminate vacuum in the
booster by pumping the brake pedal several times.
2. Push the pedal down and hold in this position.
3. Start the engine.4. The booster is OK if the pedal drops further be-
cause of extra force produced.
If the brake pedal does not drop, the vacuum system (vac-
uum hoses, check valve, etc.) is probably defective and
should be checked.
If no defect is revealed by checking the vacuum system,
the defect is in the booster itself.
ANTILOCK BRAKE SYSTEM 4F – 11
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
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.
Does the voltage match 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.
Does the voltage match 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
28Repair the open or the high resistance.
Is the repair complete?–System OK–
291. Remove the instrument cluster.
2. Check circuit PNK from fuse F4 to terminal
A19 of the I/P cluster connector B.
3. Repair any open or high resistance found in a
wiring harness, splice pack, or connector.
Is the repair complete?–System OK–
ANTILOCK BRAKE SYSTEM 4F – 13
DAEWOO V–121 BL4
Power Supply to Control Module, No DTCs Stored
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 8
41. Replace fuse EF2.
2. Turn the ignition to ON.
Does the fuse blow again?–Go to Step 6Go to Step 5
5Check the ABS function.
Is the repair complete?–System OK–
61. Turn the ignition to OFF.
2. Remove fuse EF2.
3. Disconnect the ABS connector from the
EBCM.
4. Measure the resistance to ground at terminals
17 and 18.
Does the ohmmeter show the specified value?0 WGo to Step 7Go to Step 25
7Repair the short to ground in circuit RED between
terminal 1 of engine fuse block connector C107 and
the ABS harness EBCM connector.
Is the repair complete?–System OK–
8Check fuse EF5 in the engine fuse block.
Is the fuse blown?–Go to Step 9Go to Step 13
91. Replace fuse EF5.
2. Turn the ignition to ON.
Does the fuse blow again?–Go to Step 11Go to Step 10
10Check the ABS function.
Is the repair complete?–System OK–
111. Turn the ignition to OFF.
2. Remove fuse EF5.
3. Disconnect ABS connector from the EBCM.
4. Measure the resistance to ground at terminal
15.
Does the ohmmeter show the specified value?0 WGo to Step 12Go to Step 25
121. Examine circuit RED between terminal 4 of en-
gine fuse block connector C105 and terminal 2
of the ignition switch.
2. Examine circuit PNK from terminal 4 of the
ignition switch to fuse F11 in the I/P fuse block.
3. Examine circuit PNK from fuse F11 in the I/P
fuse block to terminal 15 of the ABS EBCM
connector.
4. Repair any short to ground found in the wiring
or the ignition switch.
Is the repair complete?–System OK–
13Check fuse F11 in the I/P fuse block.
Is the fuse blown?–Go to Step 14Go to Step 18
4F – 14IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
141. Replace fuse F11.
2. Turn the ignition to ON.
Does the fuse blow again?–Go to Step 16Go to Step 15
15Check the ABS function.
Is the repair complete?–System OK–
161. Turn the ignition to OFF.
2. Remove fuse F11.
3. Disconnect ABS connector from the EBCM.
4. Measure the resistance to ground at terminal
15.
Does the ohmmeter show the specified value?0 WGo to Step 17Go to Step 25
17Repair the short to ground in circuit PNK fuse F11 of
the I/P fuse block and terminal 15 of the ABS har-
ness EBCM connector.
Is the repair complete?–System OK–
181. 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 20Go to Step 19
191. Turn the ignition switch to OFF.
2. Trace the RED wires between terminals 17 and
18 of the EBCM connector to terminal 1 of con-
nector C107 at the engine fuse block.
3. Repair the open in this circuit.
Is the repair complete?–System OK–
20Check the voltage between ground and terminal 15
of the EBCM connector.
Is the voltage within the specified value?11–14 vGo to Step 22Go to Step 21
211. Turn the ignition switch to OFF.
2. Trace circuit PNK between terminal 15 of the
ABS harness EBCM connector to fuse F11 in
the I/P fuse block.
3. Trace circuit PNK from fuse F11 of the I/P fuse
block to terminal 4 (IG1) of the ignition switch.
4. Trace circuit RED from terminal 2 (B1) of the
ignition switch to terminal 4 of connector C105
at the engine fuse block and to fuse EF5.
5. Repair the open in the wiring or possibly bad
connector terminal, defective ignition switch, or
blown fuse EF5.
Is the repair complete?–System OK–
221. Turn the ignition to OFF.
2. Check the resistance between ground and ter-
minals 19 and 16 of the EBCM connector.
Does the ohmmeter show the specified value?0 WGo to Step 23Go to Step 26
23Examine terminals 15, 19, 17, 18, and 16 of the
EBCM connector.
Is there a defective terminal?–Go to Step 24Go to Step 25
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 – 48IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
DTC C0161 – ABS Brake Switch Circuit Malfunction
StepActionValue(s)YesNo
1Step on the brake pedal.
Do the brake lights come on at all?–Go to Step 3Go to Step 2
2Remove your foot from the brake pedal.
Do the lights stay on continuously?–Go to Step 8Go to Step 11
3Check fuse EF13 in the engine compartment fuse
block.
Is fuse EF13 blown?–Go to Step 4Go to Step 6
41. Replace fuse EF13.
2. Check the new fuse.
Does the new fuse blow?–Go to Step 5Go to Step 7
51. Repair the short to ground in the brake light
circuitry.
2. Install a new fuse EF13.
Is the repair complete?–System OK–
6Repair the open in the brake light switch circuit ORN/
BLK from terminal 6 of connector C102 at the engine
fuse block to the brake light switch and circuit LT
BLU from terminal 11 of splice S301.
Is the repair complete?–System OK–
7Check for functioning of the brake lights and the ABS
system.
Is the repair complete?–System OK–
8Check the brake light switch on the brake pedal.
Is the switch faulty?–Go to Step 9Go to Step 10
9Repair the brake light switch.
Is the repair complete?–System OK–
10Repair the short to positive in the circuit YEL be-
tween the brake light switch, splice S301, the brake
lights, the center high–mounted stoplamp, and the
ABS wiring harness connector at the EBCM terminal
14.
Is the repair complete?–System OK–
111. Disconnect the EBCM connector.
2. Use a digital voltmeter (DVM) to measure volt-
age between pins 14 and 19 of the ABS har-
ness connector at the EBCM.
3. Have an assistant step on the brake pedal.
Does the DVM indicate the specified value?11–14 vGo to Step 13Go to Step 12
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–
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