GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems in Wiring Systems.

2

  1. Turn the ignition to the ON position.
  2. Place the headlamp to the PARK position.

Do all of the park lamps and license lamps illuminate?

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

Go to Step 3

3

Using a test lamp, backprobe the inoperable license lamp between the park lamp switch signal circuit and a known good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Repair a poor connection or an open in the park lamp switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step  8

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5

Using a test lamp, backprobe the inoperable license lamp between the park lamp switch signal circuit and the ground circuit.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6

Repair a poor connection or an open in the ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

--

7

Replace the inoperable license lamp. Refer to Rear License Lamp Replacement .

Did you complete the repair?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

Go to Diagnostic System Check - Lighting Systems in Wiring Systems.

Go to Step 2