GM Service Manual Online
For 1990-2009 cars only

Brake Warning Indicator Inoperative Base

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the connector at the daytime running lamp control module.
  2. Disconnect the connector at the instrument cluster.
  3. Connect a self-powered test lamp between daytime running lamp control module connector cavity E and instrument cluster connector cavity A13.
  4. Test for continuity.

Does the test lamp light?

--

Go to Step  2

Go to Step 4

2

  1. Connect a self-powered test lamp between daytime running lamp control module connector cavity H and ground.
  2. Test for continuity.

Does the test lamp light?

--

Go to Step  5

Go to Step  3

3

Repair the open in the BLK (150) wire between daytime running lamp control module and ground G201.

Does the brake indicator light?

--

System OK

--

4

Repair the open in the TAN/WHT (33) wire between daytime running lamp control module and the instrument cluster.

Does the brake indicator light?

--

System OK

--

5

Is the brake indicator lamp inoperative only when applying the parking brake, and operative with the ignition in the start position?

--

Go to Step  8

Go to Step  6

6

Is the brake indicator lamp inoperative only when you cycle the ignition switch from the LOCK position to the RUN? Normally, the lamp stays on for less than five seconds.

--

Go to Step  9

Go to Step  7

7

Is the brake indicator lamp inoperative when you cycle the ignition switch to the start position?

--

Go to Step  14

Go to Step  15

8

  1. Disconnect the park brake warning switch connector.
  2. Turn the ignition switch to RUN.
  3. Connect a fused jumper from park brake warning cavity A to ground.

Does the brake indicator light?

--

Go to Step  10

Go to Step  11

9

  1. Disconnect electronic brake control module connector C1.
  2. Turn the ignition switch to RUN.
  3. Connect a fused jumper from electronic brake control module connector C1 cavity H to ground.

Does the brake indicator light?

--

Go to Step  12

Go to Step  13

10

Is the park brake warning switch adjusted properly?

--

Go to Step  24

Go to Step  25

11

Repair the open in the TAN/WHT (33) wire between daytime running lamp control module and park brake warning switch.

Does the brake indicator light?

--

System OK

--

12

Refer to Diagnostic System Check

Does the brake indicator light?

--

System OK

--

13

  1. Disconnect the brake pressure differential switch connector.
  2. Turn the ignition switch to RUN.
  3. Connect a fused jumper from brake pressure differential switch connector cavity A to ground.

Does the brake indicator light?

--

Go to Step  16

Go to Step  17

14

  1. Backprobe the ignition switch connector from cavity B5 with a fused jumper to ground.
  2. Turn the ignition to START.

Does the brake indicator light?

--

Go to Step  18

Go to Step  19

15

  1. Disconnect the instrument cluster.
  2. Apply the parking brake
  3. Connect a self-powered test lamp from instrument cluster connector cavity A13 and ground.
  4. Turn the ignition switch to RUN.

Does the brake indicator light?

--

Go to Step  20

Go to Step  21

16

Repair the open in the BLK (150) wire between the brake pressure differential switch and ground G103.

Does the brake indicator light?

--

System OK

--

17

Repair the open in the TAN/WHT (33) wire between the daytime running lamp control module and brake pressure differential switch/electronic brake module.

Does the brake indicator light?

--

System OK

--

18

Test the ignition switch ground connection from the ignition switch to G201.

Is the connection OK?

--

Go to Step  22

Go to Step  23

19

Repair the open in TAN/WHT (33) wire between the daytime running lamp control module and the ignition switch.

Does the brake indicator light?

--

System OK

--

20

Replace the instrument cluster printed circuit.

Does the brake indicator light?

--

System OK

--

21

Replace the daytime running lamp control module.

Does the brake indicator light?

--

System OK

--

22

Replace the ignition switch.

Does the brake indicator light?

--

System OK

--

23

Repair the ignition switch ground connection from the ignition switch to G201

Does the brake indicator light?

--

System OK

--

24

Is the park brake warning switch properly connected?

--

Go to Step  26

Go to Step  27

25

Adjust the park brake warning switch.

Does the brake indicator light?

--

System OK

--

26

Replace the park brake warning switch.

Does the brake indicator light?

--

System OK

--

27

Properly connect the park brake warning switch.

Does the brake indicator light?

--

System OK

--

Brake Warning Indicator Inoperative Alarm Is Operative

Step

Action

Value(s)

Yes

No

1

  1. Apply the parking brake.
  2. Place the ignition switch in RUN.

Is the brake indicator illuminated?

--

Go to Step  5

Go to Step  2

2

  1. Disconnect the connector at the park brake warning switch.
  2. Connect a fused jumper wire between park bake warning switch connector cavity A for the TAN/WHT (33) wire and ground.

Is the brake indicator illuminated?

--

Go to Step  6

Go to Step  3

3

  1. Disconnect the connector at the instrument cluster.
  2. Connect an unpowered test lamp between instrument cluster connector cavity B17 and ground.

Does the test lamp light?

--

Go to Step  4

Go to Step  7

4

  1. Disconnect the daytime running lamp control module.
  2. Connect a self -powered test lamp at the instrument cluster connector cavity A13 for the TAN/WHT (33) wire and daytime running lamp control module connector cavity E.
  3. Test for continuity.

Does the test lamp light?

--

Go to Step  5

Go to Step  8

5

  1. Reconnect all components.
  2. Position the vehicle safely for the release of the parking brake.
  3. Release the parking brake.
  4. Start the engine while observing the instrument cluster.

Is the brake indicator illuminated while the ignition switch is in START?

--

Go to Step  9

Go to Step  10

6

Adjust the park brake warning switch.

Is the brake indicator illuminated?

--

System OK

Go to Step  24

7

Repair the open in the PNK (39) wire between the IP fuse block and the instrument cluster.

Is the brake indicator illuminated?

--

System OK

--

8

Repair the open in the TAN/WHT (33) wire between the instrument cluster and the daytime running lamp control module connector cavity E.

Is the brake indicator illuminated?

--

System OK

--

9

  1. Connect a self-powered test lamp between connector C200 pin B2 for the BLK (150) wire and ground.
  2. Test for continuity.

Does the test lamp light?

--

Go to Step  11

Go to Step  23

10

  1. Stop the engine.
  2. Backprobe ignition switch connector C200 from cavity B5 with a fused jumper to ground.
  3. Turn the ignition switch to START.

Does the brake indicator light?

--

Go to Step  12

Go to Step  13

11

  1. Disconnect the connector at the park brake warning switch.
  2. Disconnect the connector at the P/B booster fluid flow and pressure alarm delay module.
  3. Connect a self-powered test lamp between the park brake warning switch connector cavity A for the TAN/WHT (33) wire and P/B booster fluid flow and pressure alarm delay module connector cavity E for the YEL/BLK (965) wire.
  4. Test for continuity.

Does the test lamp light?

--

Go to Step  14

Go to Step  15

12

Test the ignition switch ground connection from the ignition switch to G201.

Is the connection OK?

--

Go to Step  25

Go to Step  26

13

Repair the open in the TAN/WHT (33) wire between the daytime running lamp control module connector cavity B and the ignition switch.

Does the brake indicator light?

--

System OK

--

14

  1. Disconnect the connector at the brake pressure differential switch.
  2. Disconnect the daytime running lamp control module.
  3. Connect a self-powered test lamp between brake pressure differential switch connector cavity A for the TAN/WHT (33) wire and daytime running lamp control module connector cavity F.
  4. Test for continuity.

Does the test lamp light?

--

Go to Step  16

Go to Step  17

15

Is there an open in the TAN/WHT (33) wire or in the YEL/BLK (965) wire between the Park Brake Warning Switch and the P/B booster fluid flow pressure alarm delay module?

--

Go to Step  27

Go to Step  28

16

  1. Connect a self-powered test lamp between brake pressure differential switch connector cavity B for the BLK (150) wire and ground.
  2. Test for continuity.

Does the test lamp light?

--

Go to Step  18

Go to Step  19

17

Repair the open in the TAN/WHT (33) wire between daytime running lamp control module connector cavity F and the brake pressure differential switch.

Is the brake indicator illuminated?

--

System OK

Go to Step  29

18

Check the operation of the brake pressure differential switch per combination valve warning switch test. Refer to Combination Valve Circuit .

Does the brake pressure differential switch operate as designed?

--

Go to Step  20

Go to Step  21

19

Repair the open in the BLK (150) wire between the brake pressure differential switch and ground G103.

Is the brake indicator illuminated?

--

System OK

--

20

  1. Disconnect connector C1 at the electronic brake control module.
  2. Connect a self-powered test lamp between electronic brake control module connector C1 cavity H for the TAN/WHT (33) wire and the daytime running lamp control module cavity F.
  3. Test for continuity.

Does the test lamp light?

--

Go to Step  21

Go to Step  22

21

Perform diagnostic testing of the electronic brake control module. Refer to Diagnostic System Check

Is the condition repaired?

--

System OK

Go to Step  30

22

Repair the open in the TAN/WHT (33) wire between splice S156 and the electronic brake control module.

Is the brake indicator illuminated?

--

System OK

--

23

  1. Locate the open in the BLK (150) wire between connector C200 and ground G201
  2. Repair the open.

Is the brake indicator illuminated?

--

System OK

--

24

Replace the park brake warning switch.

Is the brake indicator illuminated?

--

System OK

--

25

Replace the ignition switch.

Does the brake indicator light?

--

System OK

--

26

Repair the ignition switch ground connection from the ignition switch to G201.

Is the ground connection repaired?

--

System OK

--

27

Repair the open in the TAN/WHT (33) wire or in the YEL/BLK (965) wire between the Park Brake Warning Switch and the P/B booster fluid flow and pressure alarm delay module.

Is the brake indicator illuminated?

--

System OK

--

28

Replace the in-line diode D202.

Is the brake indicator illuminated?

--

System OK

--

29

Verify diode D101 at the underhood fuse-relay center is also not open.

Is the brake indicator illuminated?

--

System OK

--

30

Replace the electronic brake control module.

Refer to Electronic Brake Control Module Replacement

Is the brake indicator illuminated?

--

System OK

--