GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect fuse F5-F6.

Is the fuse open?

--

Go to Step 2

Go to Step 3

2

Repair a short to ground in circuit 140 or circuit 17.

Is the repair complete?

--

Go to Diagnostic System Check - Lighting Systems

--

3

Using a test light, backprobe between the stop lamp switch harness connector C1 between terminal A and ground.

Does the test light illuminate?

--

Go to Step 4

Go to Step 7

4

  1. Using a test light, backprobe the stop lamp switch harness connector C1 terminal B and ground.
  2. Depress and hold the brake pedal.

Does the test light illuminate?

--

Go to Step 5

Go to Step 6

5

Repair a poor connection or an open in circuit 17 between the stop lamp switch harness connector C2 terminal B and S205.

Is the repair complete?

--

Go to Diagnostic System Check - Lighting Systems

--

6

Adjust/replace the stop lamp switch. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes.

Is the repair complete?

--

Go to Diagnostic System Check - Lighting Systems

--

7

Repair a poor connection or an open in circuit 140.

Is the repair complete?

--

Go to Diagnostic System Check - Lighting Systems

--