2004 DAEWOO LACETTI Ground

9B – 16ILIGHTING SYSTEMS
DAEWOO V–121 BL4
HEADLAMPS
Low–Beam Headlamps Are Inoperative, High–Beam Headlamps
Are OK
StepActionValue(s)YesNo
1Check fuses Ef20 (left side headlamps) and Ef27
(right side headlamps).
Is fuse Ef20 or Ef27 blown?–Go to Step 2Go to Step 3
21. Check for a short circuit and repair if neces-
sary.
2. Replace the fuse.
Is the repair complete?–System OK–
3Check the voltage at fuses Ef20 and Ef27.
Does the voltage available at fuses Ef20 and Ef27
equal the value specified?11–14 vGo to Step 4Go to Step 9
41. Disconnect both headlamp connectors.
2. Turn the headlamps ON.
3. Select the low beams.
Does the voltage at each headlamp connector termi-
nal 5 equal the value specified?11–14 vGo to Step 6Go to Step 5
5Repair the open circuit between fuses Ef20 or Ef27
and the low beam headlamps.
Is the repair complete?–System OK–
61. Disconnect the headlamp connectors.
2. Connect an ohmmeter between ground and
either headlamp connector terminal 6.
Is the resistance equal to the value specified?0 WGo to Step 8Go to Step 7
7Repair the ground circuit.
Is the repair complete?–System OK–
8Replace the faulty headlamps.
Is the repair complete?–System OK–
91. Disconnect the headlamp switch connector.
2. Select the low beams.
3. Use an ohmmeter to check the continuity be-
tween terminals 6 and 5 of the headlamp
switch.
Does the ohmmeter indicate the value specified?0 WGo to Step 10Go to Step 11
10Replace the headlamp combination switch.
Is the repair complete?–System OK–
11Repair the open circuit between fuses Ef20 and Ef27
and the headlamp switch connector terminal 5.
Is the repair complete?–System OK–

9B – 18ILIGHTING SYSTEMS
DAEWOO V–121 BL4
High–Beam and Low–Beam Headlamps Are Inoperative On Both
Left and Right Sides
StepActionValue(s)YesNo
1Check fuses F6, Ef2, Ef20, Ef27 and Ef15.
Is any fuse blown?–Go to Step 2Go to Step 3
21. Check for a short circuit and repair if neces-
sary.
2. Replace the fuse.
Is the repair complete?–System OK–
31. Turn the low–beam headlamps ON.
2. Check the voltage at fuses Ef20, Ef27 and
Ef15.
Does the voltage at the headlamps equal the value
specified?11–14 vGo to Step 4Go to Step 9
41. Turn the low–beam headlamps ON.
2. Check the voltage at the headlamp connector
terminal 5.
3. Turn the high–beam headlamps ON.
4. Check the voltage at headlamp connector ter-
minal 4.
Does the battery voltage available at the headlamps
equal the value specified?11–14 vGo to Step 6Go to Step 5
5Repair the open circuit between fuses Ef20, Ef27
and Ef15 and the headlamps.
Is the repair complete?–System OK–
6Use an ohmmeter to check between ground and
each headlamp connector terminal 6.
Is the resistance equal to the specified value?0 WGo to Step 8Go to Step 7
7Repair the ground circuit.
Is the repair complete?–System OK–
81. Replace the faulty headlamps.
2. Check the charging system to make sure that
charging voltage is not excessively high. Re-
pair if necessary.
Is the repair complete?–System OK–
9Temporarily substitute the illumination relay in place
of the headlamp relay.
Do the headlamps operate with the substituted
relay?–Go to Step 10Go to Step 11
10Install the illumination relay in its original position,
and install a new headlamp relay.
Is the repair complete?–System OK–
111. With the headlamp relay removed, turn the
headlamp switch to the low–beam position.
2. Use an ohmmeter to check the continuity be-
tween the connector for relay terminal 85 and
ground.
Does the ohmmeter indicate the specified value?
0 WGo to Step 17Go to Step 12

LIGHTING SYSTEMS 9B – 19
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
121. Reinstall the headlamp relay.
2. Check the voltage at the light switch connector
terminal 2.
Does the voltage equal the specified value?11–14 vGo to Step 14Go to Step 13
13Repair the open circuit between headlamp relay ter-
minal 85 and the light switch connector terminal 2.
Is the repair complete?–System OK–
141. Disconnect the light switch connector.
2. Turn the headlamps to the low–beam position.
3. Use an ohmmeter to check the continuity be-
tween terminals 2 and 3 of light switch.
Does the ohmmeter indicate the specified value?
0 WGo to Step 16Go to Step 15
15Replace the light switch.
Is the repair complete?–System OK–
16Repair the open circuit between terminal 3 of light
switch connector and ground.
Is the repair complete?–System OK–
17Check the voltage at headlamp switch connector
terminal 6.
Does the voltage equal the specified value?11–14 vGo to Step 19Go to Step 18
18Repair the open circuit between headlamp switch
connector and terminal 87 of the headlamp relay.
Is the repair complete?–System OK–
191. Disconnect headlamp switch connector.
2. Turn the headlamps to the low–beam position.
3. Connect an ohmmeter between terminals 5
and 6 of headlamp switch connector. Observe
the reading on the ohmmeter.
4. Turn the headlamps to the high–beam position.
5. Connect an ohmmeter between terminals 4
and 6 of the headlamp switch. Observe the
reading on the ohmmeter.
Does the ohmmeter show the specified value for
both of the tests?
0 WGo to Step 20Go to Step 15
20Repair the open circuit between the headlamp
switch and fuses Ef20, Ef27 and Ef15.
Is the repair complete?–System OK–

9B – 20ILIGHTING SYSTEMS
DAEWOO V–121 BL4
HEADLAMP LEVELING
Headlamps Leveling System Does Not Work
StepActionValue(s)YesNo
1Check the headlamps.
Do the headlamps work?–Go to Step 3Go to Step 2
2Repair the headlamp system before completing this
diagnostic table.
Has the headlamp system been repaired?–Go to Step 3–
3Check fuses Ef20 and Ef27.
Is either of the fuses blown?–Go to Step 5Go to Step 4
41. Check for a short circuit and repair if neces-
sary.
2. Replace the blown fuse.
Is the repair complete?–System OK–
51. Turn the headlamps ON.
2. Check the voltage at fuses Ef20 and Ef27.
Is the specified voltage available at the fuses?11–14 vGo to Step 7Go to Step 6
6Repair the open circuit between the headlamp
switch and fuses Ef20 and Ef27.
Is the repair complete?–System OK–
71. Disconnect the electrical connectors at the
headlamp leveling motors.
2. Turn the headlamps ON.
3. Check the voltage at terminal 5 of the head-
lamps.
Is the specified voltage available at both headlamp
leveling motors?11–14 vGo to Step 9Go to Step 8
8Repair the open circuit between fuses Ef20 and Ef27
and the headlamps.
Is the repair complete?–System OK–
9With the headlamp leveling motors disconnected,
check the resistance between ground and terminal
6 of the headlamps.
Is the resistance equal to the specified value?
0 WGo to Step 11Go to Step 10
10Repair the ground circuit for the headlamps.
Is the repair complete?–System OK–
111. Turn the headlamps ON.
2. With the headlamps, check the voltage at ter-
minal 3 of the headlamp connector.
Is the voltage approximately equal the specified val-
ue?6.2–10.6 vGo to Step 16Go to Step 12
121. Disconnect the headlamp leveling switch.
2. Turn the headlamps ON.
3. Check the voltage at the connector 3 wire at
the headlamp leveling switch connector.
Is the voltage equal to the specified value?11–14 vGo to Step 14Go to Step 13
13Repair the open circuit between the headlamp relay
and the headlamp leveling switch.
Is the repair complete?–System OK–

9B – 22ILIGHTING SYSTEMS
DAEWOO V–121 BL4
DAYTIME RUNNING LAMPS
Diagnostic Aids
The daytime running lamp (DRL) system will not work if the
parking brake is applied. The system is designed to work
only when the engine is running and the parking brake isreleased. If the parking brake circuit is shorted to ground
or the switch stays closed when the engine is running, the
DRL system will not work.
Daytime Running Lamps (DRL) Do Not Turn ON
StepActionValue(s)YesNo
1Turn the headlamps ON with the headlamp switch.
Do the headlamps work?–Go to Step 3Go to Step 2
2Repair the regular headlamp system before com-
pleting this diagnostic table.
Does the DRL system work after the headlamps
have been repaired?–System OKGo to Step 3
3With the DRL module still disconnected, use an
ohmmeter to check the resistance between ground
and terminal 5 of the DRL module connector.
Is the resistance equal to the specified value?
0 WGo to Step 5Go to Step 4
4Repair the circuit between ground and terminal 5 of
the DRL module connector.
Is the repair complete?–System OK–
51. Release the parking brake.
2. Turn the ignition switch ON.
3. Observe the parking brake indicator lamp.
Is the parking brake indicator lamp ON?–Go to Step 6Go to Step 9
6Disconnect the electrical connector to the parking
brake lever switch.
Is the parking brake indicator lamp still ON?–Go to Step 7Go to Step 8
7Repair the short to ground in the parking brake cir-
cuit.
Is the repair complete?–System OK–
8Replace the parking brake lever switch.
Is the repair complete?–System OK–
91. Make sure the headlamps are turned OFF.
2. With the DRL module disconnected, turn the
ignition ON.
3. Check the voltage at terminal 6 of the DRL
module.
Is the voltage equal to the specified value?0 vGo to Step 11Go to Step 10
10Repair the open between fuse F4 and terminal 6 of
the DRL module.
Is the repair complete?–System OK–
11Replace the DRL module.
Is the repair complete?–System OK–

LIGHTING SYSTEMS 9B – 23
DAEWOO V–121 BL4
PARKING LAMPS AND TAILLAMPS
Parking Lamps and Taillamps Do Not Work
StepActionValue(s)YesNo
1Check the headlamps.
Do the headlamps work?–Go to Step 3Go to Step 2
2Repair the headlamps before continuing with this
chart.
After the headlamps have been repaired, are the
parking lamps and taillamps still inoperative?–Go to Step 3System OK
31. Turn the parking lamps on.
2. Use a voltmeter to check voltage at the bulb
socket positive terminal.
Does voltage at the bulb socket equal the specified
value?11–14 vGo to Step 4Go to Step 7
4Connect an ohmmeter between ground and the
lamp socket negative terminal.
Is the resistance equal to the specified value?
0 WGo to Step 6Go to Step 5
5Repair the ground circuit for the lamps.
Is the repair complete?–System OK–
6Replace the faulty bulbs.
Is the repair complete?–System OK–
7Check fuses Ef23 and Ef28.
Are any of the fuses blown?–Go to Step 8Go to Step 9
81. Check for a short circuit and repair it, if neces-
sary.
2. Replace the fuse.
Is the repair complete?–System OK–
91. Turn the headlamps on.
2. Check the voltage at fuses Ef23 (left–side illu-
mination lamp) and Ef28 (right–side illumination
lamp).
Does the voltage at the fuses equal the specified val-
ue?11–14 vGo to Step 10–
10Repair the open circuit between the fuses Ef23 and
Ef28 and the illumination lamps.
Is the repair complete?–System OK–

9B – 24ILIGHTING SYSTEMS
DAEWOO V–121 BL4
Stoplamps Do Not Work
Notice : When probing a bulb socket with a voltmeter or a test lamp, do not contact the side of the socket (ground) when
you are testing the positive contact at the bottom of the socket. If the voltage and the ground are both available at the bulb
socket, contacting both at the same time with a test probe will cause a blown fuse.
Step
ActionValue(s)YesNo
1Check fuse Ef13.
Is fuse Ef13 blown?–Go to Step 2Go to Step 3
21. Check for a short circuit and repair it, if neces-
sary.
2. Replace the fuse.
Is the repair complete?–System OK–
3Use a voltmeter to check the voltage at fuse Ef13.
Is the voltage at Ef13 equal to the specified value?11–14 vGo to Step 5Go to Step 4
4Repair the power supply circuit for fuse Ef13.
Is the repair complete?–System OK–
51. Press the brake pedal.
2. Check the positive terminals of the bulb sock-
ets with a test lamp.
Does the test lamp illuminate?–Go to Step 6Go to Step 8
6Connect an ohmmeter between ground and the sto-
plamp ground terminal.
Is the resistance equal to the specified value?0 WGo to Step 8Go to Step 7
7Repair the ground circuit.
Is the repair complete?–System OK–
81. Disconnect the wiring connector from the brake
switch.
2. Press the brake pedal.
3. Use an ohmmeter to check continuity between
terminals 2 and 4.
Is the resistance equal to the specified value?0 WGo to Step 10Go to Step 9
9Replace the brake switch.
Is the repair complete?–System OK–
101. Disconnect the brake switch electrical connec-
tor.
2. Check the voltage at terminal 2.
Does the voltmeter show the specified value?11–14 vGo to Step 12Go to Step 11
11Repair the open circuit between the fuse Ef13 and
the brake switch.
Is the repair complete?–System OK–
12Repair the open circuit between the brake switch
and the stoplamps.
Is the repair complete?–System OK–

LIGHTING SYSTEMS 9B – 25
DAEWOO V–121 BL4
Center High–Mounted Stoplamp (CHMSL) Does Not Work
StepActionValue(s)YesNo
1Check the stoplamps.
Do the stoplamps work?–Go to Step 3Go to Step 2
2Repair the stoplamps before completing this diag-
nostic table.
Does the CHMSL work after the stoplamps have
been repaired?–System OKGo to Step 3
31. Remove the CHMSL lamp bulb.
2. Visually and physically check the CHMSL lamp
bulb.
Is the lamp bulb defective?–Go to Step 4Go to Step 5
4Replace the CHMSL lamp bulb.
Is the repair complete?–System OK–
51. Disconnect the CHMSL connector.
2. Use an ohmmeter to measure the resistance
between ground and the BLK wire in the
CHMSL connector.
Is the resistance equal to the specified value?0 WGo to Step 7Go to Step 6
6Repair the open circuit between ground and the BLK
wire in the CHMSL connector.
Is the repair complete?–System OK–
7Repair the open circuit between the stoplamp switch
and the CHMSL.
Is the repair complete?–System OK–