Daewoo Nubira. Manual - part 50

HYDRAULIC BRAKES  4A – 7

DAEWOO V–121 BL4

Brake Lamp Warning Circuit Diagnosis

Step

Action

Value(s)

Yes

No

1

Turn the ignition ON.
Is the brake warning lamp always on?

Go toStep 2

Go toStep 18

2

Check the ABS warning lamp.
Is the ABS warning lamp also on?

Go toStep 3

Go toStep 4

3

Use a scan tool to check for diagnostic trouble codes
(DTCs) and follow the procedures for any DTCs
found.
Is the lamp still on?

Go toStep 4

System OK

4

Release the parking brake fully.
Is the lamp off?

System OK

Go toStep 5

5

Check the brake fluid level.
Is the fluid level OK?

Go toStep 7

Go toStep 6

6

1.  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 toStep 7

System OK

7

Disconnect the harness connector from the brake
fluid level switch.
Is the lamp on?

Go toStep 9

Go toStep 8

8

Replace the brake fluid level switch.
Is the repair complete?

System OK

9

1.  Connect the brake fluid level switch.
2.  Disconnect the parking brake switch.

Is the lamp on?

Go toStep 11

Go toStep 10

10

Replace the parking brake switch.
Is the repair complete?

System OK

11

Connect the parking brake switch.
Is the vehicle equipped with ABS?

Go toStep 12

Go toStep 14

12

1.  Turn the ignition OFF.
2.  Disconnect the electronic brake control module

(EBCM) connector.

3.  Turn the ignition ON.

Is the lamp on?

Go toStep 14

Go toStep 13

13

Replace the electronic brake control module
(EBCM).
Is the repair complete?

System OK

14

1.  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 A2 and
the brake fluid level switch.

Is the problem found?

Go toStep 17

Go toStep 15

15

Check for a short to ground in the wiring between the
instrument cluster terminal A2 and the parking brake
switch.
Is the problem found?

Go toStep 17

Go toStep 16

4A – 8

I

HYDRAULIC BRAKES

DAEWOO V–121 BL4

Step

No

Yes

Value(s)

Action

16

Check for a short to ground in the wiring between the
instrument cluster terminal A2 and the EBCM con-
nector terminal 21.
Is the problem found?

Go toStep 17

Go toStep 18

17

Repair the wiring as needed.
Is the repair complete?

System OK

18

Check 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 OK

Go toStep 19

19

When 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 toStep 20

Go toStep 27

20

1.  Turn the ignition OFF.
2.  Inspect the kick panel fuse F5.

Is the fuse OK?

Go toStep 22

Go toStep 21

21

Replace the fuse.
Is the repair complete?

System OK

22

Inspect the brake warning lamp bulb.
Is the bulb OK?

Go toStep 24

Go toStep 23

23

Replace the bulb.
Is the repair complete?

System OK

24

1.  Disconnect the instrument cluster connector.
2.  Turn the ignition ON.
3.  Measure the voltage at the instrument cluster

connector terminal A2.

Does the voltagemeasurewithin the value specified?

11–14 v

Go toStep 25

Go toStep 26

25

1.  Turn the ignition OFF.
2.  Repair the open in the instrument cluster.

Is the repair complete?

System OK

26

1.  Turn the ignition OFF.
2.  Repair the open in the wiring between the in-

strument cluster connector terminal A2 and the
ignition switch.

Is the repair complete?

System OK

27

Apply the parking brake again.
Does the parking brake warning lamp operate with
the parking brake applied?

Go toStep 28

Go toStep 30

28

Remove the brake fluid reservoir cap.
Does the parking brake warning lamp operate with
the cap from the brake fluid reservoir removed?

Go toStep 29

Go toStep 32

29

Check for an open between the instrument cluster
connector terminal B13 and the EBCM connector
terminal 21.
Is the problem found?

Go toStep 17

Go toStep 13

HYDRAULIC BRAKES  4A – 9

DAEWOO V–121 BL4

Step

No

Yes

Value(s)

Action

30

1.  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 toStep 10

Go toStep 31

31

1.  Turn the ignition OFF.
2.  Repair the open in the wire between the instru-

ment cluster connector terminal B13 and the
parking brake switch connector terminal.

Is the repair complete?

System OK

32

1.  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 toStep 8

Go toStep 33

33

1.  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 toStep 34

Go toStep 35

34

Repair the open in the wiring between ground and
the brake fluid level switch.
Is the repair complete?

System OK

35

Repair the open in the wiring between the instrument
cluster connector terminal B13 and the brake fluid
level switch.
Is the repair complete?

System OK

 

4A – 10

I

HYDRAULIC BRAKES

DAEWOO V–121 BL4

MAINTENANCE AND REPAIR

ON–VEHICLE SERVICE

MANUAL BLEEDING THE BRAKES

1.  Remove the booster reserve by applying the brakes

several times with the engine OFF until all the re-
serve is depleted.

Important : If the master cylinder is known or suspected
to have air in the bore, then it must be bled before any
wheel cylinder or caliper is bled.

2.  Fill the master cylinder reservoir with brake fluid.

Keep the master cylinder at least one–half full of
fluid during the bleeding operation.

3.  Disconnect the front brake line(s) at the master cyl-

inder.

4.  Allow the brake fluid to fill the master cylinder until it

begins to flow from the front pipe connector port.

5.  Connect the front brake line(s) to the master cylin-

der.

Tighten

Tighten the brake lines to 16 N

S

m (12 lb–ft).