2004 DAEWOO LACETTI Lamp

4A – 6IHYDRAULIC BRAKES
DAEWOO V–121 BL4
STOP LAMP WARNING CIRCUIT DIAGNOSIS
J3B14A03
10A30
F4
32
A19
A13 A14 A1 A2B15 C201
31C201IP/Fuse
Block C201
C202
C110C108 S301 WHT
BRN
BRN
Parking
Brake
SwitchBrake
Fluid
Switch
BLKBRN LT GRN
DK
GRN
DK
GRN LT GRN/
BLK
LT GRN/
BLKPPL/
WHT
PPL/
WHT
PPL/
WHTPPL/
WHT PPL/
WHT
PPL/
WHT ABS
Warning
Lamp TCS
Active
Warning
Lamp Parking
Brake
Warning
Lamp Charging
Warning
Hot in Run and Start
PNK
Cluster PNK
EBCM”L” Ter.
Generator 1 12
2
20 2222 16 41 13
3
4
11 1 215
8
21
G303
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. When the ignition is turned ON, the brake warning
lamp should initially illuminate and then dim for ABS
equipped vehicles. This is done as a bulb check.
On vehicles that are not equipped with ABS, the
brake warning lamp should only illuminate when
either the brake fluid reservoir is low or the parking
brake is applied.
7. The brake fluid level switch is a normally open
switch. If the brake warning lamp is off after discon-
necting the switch, the brake fluid level switch is
stuck closed.9. If the brake warning lamp is still on after discon-
necting the parking brake switch, there is a short to
ground in the wire to the parking brake switch.
12. If the other checks have been properly performed
and the brake warning lamp is off after disconnect-
ing the electronic brake control module (EBCM) J1
connector, the EBCM is faulty.
19. If the brake warning lamp does not operate while
performing any of the functions, the fault should be
in the ignition feed to the circuit.
24. This step determines if the problem is in the ignition
feed to the circuit or in the instrument cluster.
30. The brake warning lamp should illuminate when
jumpering the parking brake connector to ground.
32. If the brake warning lamp is on after jumpering the
brake fluid level switch terminals, the switch is
faulty.

HYDRAULIC BRAKES 4A – 7
DAEWOO V–121 BL4
Stop Lamp Warning Circuit Diagnosis
StepActionValue(s)YesNo
1Turn the ignition ON.
Is the brake warning lamp always on?–Go to Step 2Go to Step 18
2Check the ABS warning lamp.
Is the ABS warning lamp also on?–Go to Step 3Go to Step 4
3Use a scan tool to check for diagnostic trouble codes
(DTCs) and follow the procedures for any DTCs
found.
Is the lamp still on?–Go to Step 4System OK
4Release the parking brake fully.
Is the lamp off?–System OKGo to Step 5
5Check the brake fluid level.
Is the fluid level OK?–Go to Step 7Go to Step 6
61. Fill the brake fluid reservoir with clean DOT 3
equivalent hydraulic fluid.
2. Replace the cap on the fluid reservoir.
Is the lamp on?– Go to Step 7System OK
7Disconnect the harness connector from the brake
fluid level switch.
Is the lamp on?–Go to Step 9Go to Step 8
8Replace the brake fluid level switch.
Is the repair complete?–System OK–
91. Connect the brake fluid level switch.
2. Disconnect the parking brake switch.
Is the lamp on?–Go to Step 11Go to Step 10
10Replace the parking brake switch.
Is the repair complete?–System OK–
11Connect the parking brake switch.
Is the vehicle equipped with ABS?–Go to Step 12Go to Step 14
121. Turn the ignition OFF.
2. Disconnect the electronic brake control module
(EBCM) connector.
3. Turn the ignition ON.
Is the lamp on?–Go to Step 14Go to Step 13
13Replace the electronic brake control module
(EBCM).
Is the repair complete?–System OK–
141. Turn the ignition OFF.
2. Connect the EBCM connector.
3. Check for a short to ground in the wiring be-
tween the instrument cluster terminal A19(B15)
and the brake fluid level switch.
Is the problem found?–Go to Step 17Go to Step 15
15Check for a short to ground in the wiring between the
instrument cluster terminal A19(B15) and the park-
ing brake switch.
Is the problem found?–Go to Step 17Go to Step 16

4A – 8IHYDRAULIC BRAKES
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
16Check for a short to ground in the wiring between the
instrument cluster terminal A19(B15) and the EBCM
connector terminal 21.
Is the problem found?–Go to Step 17Go to Step 18
17Repair the wiring as needed.
Is the repair complete?–System OK–
18Check the brake lamp after doing each of the follow-
ing functions:
S Apply the parking brake.
S Remove the cap from the brake fluid reservoir.
S On vehicles equipped with ABS, command the
lamp on using a scan tool.
Does the brake warning lamp operate for all of these
conditions?–System OKGo to Step 19
19When the operations listed in step 18 were per-
formed, the brake warning lamp did not function.
Did the brake warning lamp fail to light for all of the
operations listed in step 18?–Go to Step 20Go to Step 27
201. Turn the ignition OFF.
2. Inspect the kick panel fuse F4.
Is the fuse OK?–Go to Step 22Go to Step 21
21Replace the fuse.
Is the repair complete?–System OK–
22Inspect the brake warning lamp bulb.
Is the bulb OK?–Go to Step 24Go to Step 23
23Replace the bulb.
Is the repair complete?–System OK–
241. Disconnect the instrument cluster connector.
2. Turn the ignition ON.
3. Measure the voltage at the instrument cluster
connector terminal A19(B15).
Does the voltage measure within the value speci-
fied?11–14 vGo to Step 25Go to Step 26
251. Turn the ignition OFF.
2. Repair the open in the instrument cluster.
Is the repair complete?–System OK–
261. Turn the ignition OFF.
2. Repair the open in the wiring between the in-
strument cluster connector terminal A19(B15)
and the ignition switch.
Is the repair complete?–System OK–
27Apply the parking brake again.
Does the parking brake warning lamp operate with
the parking brake applied?–Go to Step 28Go to Step 30
28Remove the brake fluid reservoir cap.
Does the parking brake warning lamp operate with
the cap from the brake fluid reservoir removed?–Go to Step 29Go to Step 32
29Check for an open between the instrument cluster
connector terminal A1 and the EBCM connector ter-
minal 21.
Is the problem found?–Go to Step 17Go to Step 13

HYDRAULIC BRAKES 4A – 9
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
301. Turn the ignition ON.
2. Disconnect the parking brake switch.
3. Jumper the parking brake switch connector
terminal to ground.
Is the lamp on?–Go to Step 10Go to Step 31
311. Turn the ignition OFF.
2. Repair the open in the wire between the instru-
ment cluster connector terminal A1 and the
parking brake switch connector terminal.
3. Is the repair complete?
Is the repair complete?–System OK–
321. Disconnect the brake fluid level switch.
2. Turn the ignition ON.
3. Jumper the brake fluid level switch connector
terminals.
Is the lamp on?–Go to Step 8Go to Step 33
331. Turn the ignition OFF.
2. Connect a test light between battery positive
and the BRN/WHT wire terminal of the brake
fluid level switch.
Is the test light on?–Go to Step 34Go to Step 35
34Repair the open in the wiring between ground and
the brake fluid level switch.
Is the repair complete?–System OK–
35Repair the open in the wiring between the instrument
cluster connector terminal A1 and the brake fluid lev-
el switch.
Is the repair complete?–System OK–

HYDRAULIC BRAKES 4A – 15
DAEWOO V–121 BL4
Installation Procedure
1. Install the new disc brake hose to the caliper with
new seal rings and the bolt.
Tighten
Tighten the front disc brake hose–to–caliper bolt to 40
NSm (30 lb–ft).
2. Slide the brake hose on the steering knuckle shaft
”C” bracket.
3. Connect the brake pipe line to the brake hose on
the wheel housing bracket on each side of the ve-
hicle.
Tighten
Tighten the brake line to 16 NSm (12 lb–ft).
4. Lower the vehicle.
5. Bleed the brake system. Refer to ”Manual Bleeding
the Brakes” in this section.
6. Check the brake system for leaks.
STOPLAMP SWITCH
(Left–Hand Drive Shown, Right–Hand Drive
Similar)
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the stoplamp switch from the plug con-
nector.
3. Turn the switch. Remove the switch from the brake
pedal bracket.
Installation Procedure
1. Place the stoplamp switch into the plug connector.
2. Twist the stoplamp switch into the brake pedal
bracket hole.
3. Depress the brake pedal and pull the switch plung-
er to its maximum setting to adjust the switch.
4. Release the plunger and pull up on the pedal.
5. Connect the negative battery cable.

HYDRAULIC BRAKES 4A – 17
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
WARNING LAMP OPERATION
This brake system uses a BRAKE warning lamp located
in the instrument panel cluster. When the ignition switch
is in the START position, the BRAKE warning lamp should
illuminate. It should go off when the ignition switch returns
to the ON position.The following conditions will activate the BRAKE warning
lamp:
S The lamp should be on whenever the parking brake
is applied and the ignition switch is in the ON posi-
tion.
S A low fluid level in the master cylinder will turn the
BRAKE lamp on.

POWER BOOSTER 4C – 3
DAEWOO V–121 BL4
2. Remove the shaft and the rubber O–ring.
3. Remove the clip on the vacuum hose connection on
the booster.
4. Disconnect the brake stoplamp switch.
5. Remove the brake pedal spring.
6. Disconnect the clip and the pushrod pin from the
pedal bracket assembly. Refer to Section 4A, Hy-
draulic Brakes.
7. Remove the booster mounting nuts from the studs
protruding from the dash panel and remove the
booster.
8. Remove the rubber boot.
9. Holding the hex nut, twist off the pushrod clevis.
10. Remove the hex nut from the pushrod.

POWER BOOSTER 4C – 5
DAEWOO V–121 BL4
8. Install the new vacuum hose to the booster. Refer
to ”Vacuum Hose” in this section.
9. Install the hose clamps on the vacuum hose, and
snap the vacuum hose in the revolving clip.
10. Install the pushrod pin to the brake pedal bracket
assembly and connect the clip and the spring. Re-
fer to Section 4A, Hydraulic Brakes.
11. Install the brake stoplamp switch. Refer to Section
4A, Hydraulic Brakes.