GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the stop lamp operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

  1. Depress the brake pedal.
  2. Release the brake pedal.

Do the stop lamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Disconnect the stop lamp switch.

Are the stop lamps illuminated?

Go to Step 4

Go to Step 6

4

Remove the stop lamp relay.

Are the stop lamps illuminated?

Go to Step 8

Go to Step 5

5

Test the stop lamp relay control circuit of the stop lamp relay for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

Inspect for poor connections at the harness connector of the stop lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections , and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair the short to voltage in the stop lamp voltage supply circuit between the stop lamp relay and the stop lamps.

Did you complete the repair?

Go to Step 11

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9

Replace the stop lamp switch.

Did you complete the replacement?

Go to Step 11

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10

Replace the stop lamp relay.

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3