GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Inspect the suspect bulbs for damage or for an open filament.
  2. Verify that the connector seals are not damaged or missing.

Are the bulbs and connectors OK?

--

Go to Step 2

Go to Step 7

2

Is the inoperative lamp the center high mounted stop lamp (CHMSL)?

--

Go to Step 4

Go to Step 3

3

  1. Using a test light, backprobe between the inoperative stop lamp harness connector terminal A to ground.
  2. Press the brake pedal.

Does the test light illuminate?

--

Go to Step 11

Go to Step 9

4

  1. Using a test light, to backprobe the CHMSL harness connector terminal A to ground.
  2. Press the brake pedal.

Does the test light illuminate?

--

Go to Step 5

Go to Step 8

5

  1. Using a test light, backprobe the CHMSL harness connector terminal A to terminal B.
  2. Press the brake pedal.

Does the test light illuminate?

--

Go to Step 6

Go to Step 10

6

Replace the CHMSL. Refer to High Mount Stop Lamp Replacement

Has the repair been made?

--

Go to Exterior Lights System Check

--

7

Replace the damaged component.

Has the repair been made?

--

Go to Exterior Lights System Check

--

8

Repair the poor connection or an open in circuit 17 between S205 and the CHMSL harness connector terminal A.

Has the repair been made?

--

Go to Exterior Lights System Check

--

9

Repair the poor connection or an open in circuit 17 between S205 and connector C201 terminal A6.

Has the repair been made?

--

Go to Exterior Lights System Check

--

10

Repair the poor connection or an open in circuit 350 between the CHMSL harness connector terminal B and G302.

Has the repair been made?

--

Go to Exterior Lights System Check

--

11

Replace the tail/stop/turn lamp. Refer to Tail Lamp Bulb Replacement

Has the repair been made?

--

Go to Exterior Lights System Check

--