GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Turn ON the park lamps.

Do the clearance lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are the park lamps illuminated?

Go to Step 4

Go to Park, License, and Tail Lamps Inoperative

4

Are all clearance lamps inoperative?

Go to Step 7

Go to Step 5

5

Test the clearance lamp supply voltage and ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Inspect for poor connections at the harness connector of the clearance lamp. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Repair the interior park lamps supply voltage circuit of the clearance lamps for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs.

Did you complete the repair?

Go to Step 9

--

8

Replace the affected clearance lamp bulb. Refer to Roof Marker Lamp Replacement.

Did you complete the replacement?

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3