GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect fuse 23.

Is the fuse open?

--

Go to Step 8

Go to Step 2

2

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 3

Go to Step 6

3

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

Does the test light illuminate?

--

Go to Step 4

Go to Step 5

4

Repair the poor connection or an open in circuit 17 between the stop lamp switch and S205.

Has the repair been made?

--

Go to Exterior Lights System Check

--

5

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

Has the repair been made?

--

Go to Exterior Lights System Check

--

6

Repair the poor connection or an open in circuit 140.

Has the repair been made?

--

Go to Exterior Lights System Check

--

7

Repair a short to ground in circuit 140.

Has the repair been made?

--

Go to Exterior Lights System Check

--

8

Check circuit 140 for a short to ground.

Is there a short to ground in circuit 140?

--

Go to Step 7

Go to Step 9

9

Repair a short to ground in circuit 17.

Has the repair been made?

--

Go to Exterior Lights System Check

--