GM Service Manual Online
For 1990-2009 cars only

Stop Lamps Inoperative Stop Lamps

Step

Action

Value(s)

Yes

No

1

Check the STOP LAMPS fuse.

Is the STOP LAMPS fuse open?

--

Go to Step 8

Go to Step 2

2

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

Is the test lamp on?

--

Go to Step 3

Go to Step 6

3

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

Is the test lamp on?

--

Go to Step 4

Go to Step 5

4

Repair poor connection or open in circuit 17 between the stop lamp switch and S413.

Is the repair complete?

--

Go to Exterior Lights System Check

--

5

Adjust/replace the stop lamp switch. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement in Hydraulic Brakes for service procedure.

Is the repair complete?

--

Go to Exterior Lights System Check

--

6

Repair poor connection or open in circuit 140.

Is the repair complete?

--

Go to Exterior Lights System Check

--

7

Repair a short to ground in circuit 140.

Is the repair complete?

--

Go to Exterior Lights System Check

--

8

Check for a short to ground in circuit 140.

Is there a short to ground in circuit 140?

--

Go to Step 7

Go to Step 9

9

Repair short to ground in circuit 17.

Is the repair complete?

--

Go to Exterior Lights System Check

--

Stop Lamps Inoperative One Stop Lamp Inoperative Only

Step

Action

Value(s)

Yes

No

1

  1. Check the suspect bulbs for damage or an open filament.
  2. Check the connectors to be sure the connector seals are not damaged or missing.

Are the bulbs and connectors OK?

--

Go to Step 2

Go to Step 9

2

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

Is the test lamp on?

--

Go to Step 4

Go to Step 3

3

Repair poor connection or open in circuit 17 between S413 and the inoperative stop lamp harness connector terminal A.

Is the repair complete?

--

Go to Exterior Lights System Check

--

4

Is the lamp that is inoperative the Center High Mounted Stop Lamp (CHMSL)?

--

Go to Step 6

Go to Step 5

5

Replace the tail/stop lamp. Refer to Tail Lamp Replacement for service procedure.

Is the repair complete?

--

Go to Exterior Lights System Check

--

6

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

Is the test lamp on?

--

Go to Step 8

Go to Step 7

7

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

Is the repair complete?

--

Go to Exterior Lights System Check

--

8

Replace the CHMSL. Refer to High Mount Stop Lamp Replacement or High Mount Stop Lamp Replacement for service procedure.

Is the repair complete?

--

Go to Exterior Lights System Check

--

9

Replace the damaged component.

Is the repair complete?

--

Go to Exterior Lights System Check

--