GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Place the headlamp switch in the park lamps ON position.

Do all the park lamps illuminate correctly?

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

Go to Step 3

3

Are all of the park lamps inoperative?

Go to Step 5

Go to Step 4

4

  1. Disconnect the inoperative park lamp.
  2. Turn the headlamp switch to the park lamps ON position.
  3. Test the supply and ground circuits of the inoperative lamp for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

5

Test the park lamp switch signal of the body control module for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and fix the concern?

Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector of the inoperative lamp. 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 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the body control module (BCM). 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 10

Go to Step 9

8

Replace the inoperative lamp. Refer to Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement , Tail Lamp Assembly and /or Backup, Sidemarker, Stop, Turn Signal Bulb Replacement , or License Lamp Bulb Replacement .

Did you complete the replacement?

Go to Step 10

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9

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3