GM Service Manual Online
For 1990-2009 cars only

Brake Warning Indicator Inoperative During Bulb Test

Step

Action

Value(s)

Yes

No

1

Was the instrument cluster diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the Electronic Brake Traction Control Module (EBTCM) connector C1.
  3. Turn the ignition switch to the RUN position.
  4. Connect a fused jumper from the EBTCM connector C1 terminal B5 (circuit 209) to ground.

Is the BRAKE warning indicator light on?

--

Go to Step 6

Go to Step 3

3

Check for a poor connection or open between the instrument cluster harness connector terminal B3 (circuit 209) and the EBTCM harness connector C1 terminal B5.

Is there a poor connection or open in circuit 209?

--

Go to Step 5

Go to Step 4

4

  1. Check the BRAKE warning indicator lamp bulb for an open filament.
  2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement

Is the repair complete?

--

Go to Step 7

--

5

Repair poor connection or open in circuit 209 between the instrument cluster harness connector terminal B3 and the EBTCM harness connector C1 terminal B5.

Is the repair complete?

--

Go to Step 7

--

6

Refer to Diagnostic System Check - ABS (RPO L36) or Diagnostic System Check - ABS (RPO LX5)

Is the action complete?

--

Go to Step 7

--

7

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect connectors/components removed.

Is the action complete?

--

Go to Diagnostic System Check - Instrument Cluster

--

Brake Warning Indicator Inoperative with Park Brake Applied

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Turn the ignition switch to RUN position.

Did the BRAKE warning indicator on for 3 seconds during bulb test?

--

Go to Step 3

Go to Brake Warning Indicator Inoperative

3

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the park brake indicator switch connector.
  3. Connect a 3A fused jumper between the park brake indicator switch harness connector terminal A (circuit  1830) and ground. Refer to Audible Warnings Schematics .
  4. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 4

Go to Step 5

4

Replace the park brake indicator switch. Refer to Parking Brake Indicator Switch Replacement .

Is the repair complete?

--

System OK

--

5

  1. Turn the ignition switch to the LOCK position.
  2. Using a 3A fused jumper, backprobe from the daytime running lights (DRL) control module connector C2 terminal E to ground.
  3. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 6

Go to Step 7

6

Repair poor connection or open in circuit  1830 between the DRL control module connector C2 terminal E and the park brake indicator switch connector terminal A.

Is the repair complete?

--

System OK

--

7

  1. Turn the ignition switch to the LOCK position.
  2. Using a 3A fused jumper, backprobe between the DRL control module connector C2 terminal D and ground.
  3. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 8

Go to Step 9

8

Replace the DRL control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Is the repair complete?

--

System OK

--

9

  1. Turn the ignition switch to the LOCK position.
  2. Using a fused jumper, backprobe between the body control module (BCM) connector C1 terminal D5 and ground.
  3. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 10

Go to Step 11

10

Repair the poor connection or open in circuit 233 between DRL control module connector C2 terminal D and the BCM connector C1 terminal D5.

Is the repair complete?

--

System OK

--

11

Refer to Diagnostic System Check - Body Control System .

Is the action complete?

--

System OK

--

12

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect connectors/components removed.

Is the action complete?

--

Go to Diagnostic System Check - Instrument Cluster

--

Brake Warning Indicator Inoperative with Low Brake Fluid

Step

Action

Value(s)

Yes

No

1

Turn the ignition switch to RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 2

Go to Brake Warning Indicator Inoperative

2

  1. Disconnect the brake fluid level indicator switch.
  2. Connect a 3A fused jumper between the brake fluid level indicator switch terminal A (circuit 209) and B (circuit 1650).
  3. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 3

Go to Step 4

3

Replace the brake fluid level indicator switch. Refer to Brake Fluid Level Indicator Switch Replacement

Is the repair complete?

--

System OK

--

4

Check for a poor connection or open between the brake fluid level indicator switch connector terminal B (circuit 1650) and ground.

Is a poor connection or open in circuit 1650?

--

Go to Step 5

Go to Step 6

5

Repair poor connection or open in circuit  1650.

Is the repair complete?

--

System OK

--

6

Repair poor connection or open in circuit 209.

Is the repair complete?

--

System OK

--

Brake Warning Indicator Inoperative during ABS Malfunctioin

Step

Action

Value(s)

Yes

No

1

Was the ABS diagnostic system check performed?

--

Go to Step 2

Go to (RPO) L36 Diagnostic System Check - ABS or Diagnostic System Check - ABS (RPO) LX5 for futher diagnosis and testing.

2

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the EBTCM connector C1.
  3. Using a 3A fused jumper, connect between the EBTCM harness connector C1 terminal B5 (circuit 209) and ground.
  4. Turn the ignition switch to the RUN position.

Is the BRAKE warning indicator on?

--

Go to Step 3

Go to Step 4

3

Refer to General System Description

Is the action complete?

--

Go to Step 5

--

4

Repair poor connection or open in circuit 209 between the EBTCM connector C1 terminal B5 and the instrument cluster connector terminal B3.

Is the repair complete?

--

Go to Step 5

--

5

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect connector/components removed.

Is the action complete?

--

Go to Diagnostic System Check - Instrument Cluster

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