GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition OFF.
  2. Disconnect the stoplamp switch.

Do the brake lamps go out?

--

Go to Step 2

Go to Step 3

2

Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

--

System OK

--

3

Remove the center high mounted stop lamp (CHMSL) fuse.

Do the brake lamps go out?

--

Go to Step 4

Go to Step 5

4

Locate and repair the short to voltage in CKT 1620 (LT BLU)e

Is the repair complete?

--

System OK

--

5

Remove the VEH STOP fuse.

Does the brake lamps go out?

--

Go to Step 6

Go to Step 7

6

Locate and repair the short to voltage in CKT 17 (WHT).

Is the repair complete?

--

System OK

--

7

Locate and repair the short to voltage in CKT 1320 (LT BLU).

Is the repair complete?

--

System OK

--