GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the marker lamps are inoperative.

Do the marker lamps operate normally?

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

Go to Step 3

3

Place the headlamp switch in the PARK position.

Do the park lamps operate normally?

Go to Step 4

Go to Symptoms - Lighting Systems

4

Inspect the inoperative bulb and socket for an open filament or poor terminal connections.

Does any lamp have an open filament or poor terminal connections?

Go to Step 6

Go to Step 5

5

Repair the open or high resistance in one of the following circuits. Refer to Wiring Repairs in Wiring Systems:

    • Marker lamp supply voltage
    • Front turn signal lamp supply voltage - domestic vehicle only
    • Ground - export vehicle only

Did you complete the repair?

Go to Step 7

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6

Replace the defective bulb or repair/replace the socket. refer to Wiring Repairs in wiring systems.

Did you complete the repair?

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3