GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting Systems Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

Verify that the stop lamps are always on.

Do the stop lamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Disconnect the stop lamp switch.

Do the stop lamps remain illuminated?

Go to Step 4

Go to Step 5

4

Repair the short to voltage in one of the following circuits. Refer to Wiring Repairs in Wiring Systems.

    • CHMSL supply voltage
    • Stop lamp switch signal

Did you complete the repair?

Go to Step 6

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5

Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement .

Did you complete the repair?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3