GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the park brake warning switch connector.
  2. Turn the ignition switch to RUN.

Does the brake indicator remain on?

--

Go to Step  2

Go to Step  3

2

Disconnect the brake pressure warning switch connector.

Does the brake indicator remain on?

--

Go to Step  4

Go to Step  5

3

If the park brake warning switch is not properly adjusted, adjust the switch.

Is the repair complete?

--

Go to Brake Warning System Check

--

4

Disconnect electronic brake control module.

Does the brake indicator remain on?

--

Go to Step  6

Go to Step  7

5

Refer to brake system testing for diagnosis of the hydraulic brake system. Perform any repairs as necessary.

Is the repair complete?

--

Go to Brake Warning System Check

--

6

Disconnect the body control module.

Does the brake indicator remain on?

--

Go to Step 8

Go to Step  9

7

Refer to antilock brake system diagnosis. Perform any repairs as necessary.

Is the repair complete?

--

Go to Brake Warning System Check

--

8

  1. Disconnect the instrument cluster connector.
  2. Connect a DMM test lamp from instrument cluster cavity A6 to B+.
  3. Test for a short to ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

9

  1. Connect a DMM test lamp at the body control module connector C1 cavity  B10, CKT 1134 (LT BLU) and B+.
  2. Test for short to ground.

Does the test lamp light?

--

Go to Step  12

Go to Step  13

10

Locate and repair open in CKT 340 (ORN) between instrument cluster cavity  A10 and the IP fuse block.

Is the repair complete?

--

Go to Brake Warning System Check

--

11

Replace instrument cluster printed circuit board.

Is the repair complete?

--

Go to Brake Warning System Check

--

12

Locate and repair open in CKT 1134 (LT BLU) between body control module connector C1 cavity B10 and park brake warning switch cavity  A.

Is the repair complete?

--

Go to Brake Warning System Check

--

13

  1. Connect a DMM from the electronic brake control module connector C2 cavity  A to ground.
  2. Test for short to ground.

Does the test lamp light?

--

Go to Step  14

Go to Step  15

14

Locate and repair the open between the electronic brake control module connector C2 cavity A and the IP fuse block.

Is the repair complete?

--

Go to Brake Warning System Check

--

15

  1. Connect a DMM between the electronic brake control module connector C2 cavity H to ground.
  2. Test for short to ground.

Does the test lamp light?

--

Go to Step  16

Go to Step  17

16

Locate and repair open in CKT 680 (PPL) between the electronic brake control module connector C1 cavity H and the brake pressure warning switch cavity  B.

Is the repair complete?

--

Go to Brake Warning System Check

--

17

  1. Connect a DMM between the brake pressure warning switch CKT 350 (BLK) at cavity A to ground.
  2. Test for a short to ground.

Does the test lamp light?

--

Go to Step  18

Go to Step  19

18

Locate and repair open in CKT 350 (BLK) between brake pressure warning switch and ground G102.

Is the repair complete?

--

Go to Brake Warning System Check

--

19

Replace the brake pressure warning switch.

Is the repair complete?

--

Go to Brake Warning System Check

--