GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics in Instrument Panel, Gauges and Console

1

Did you perform the Lighting Diagnostic System Check?

Go to Step 3

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition with the engine OFF.
  2. Turn ON the headlamp switch.
  3. Turn ON the high beams.

Does the high beam indicator operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Do the high beam headlamps function properly?

Go to Step 4

Go to Headlamps Inoperative - High Beams

4

  1. Turn ON the ignition with the engine OFF.
  2. Turn ON the headlamps.
  3. Turn ON the high beams.
  4. With the scan tool, observe the high beam switch parameter under the BCM.

Does the scan tool display ON?

Go to Step 5

Go to Step 7

5

Test the head lamp dimmer switch high beam signal circuit of the IPC for high resistance or an open. 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

6

Inspect for poor connections at the IPC. 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 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 IPC or lamp as necessary. Refer to Instrument Cluster Replacement or Instrument Cluster Bulb Replacement in Instrument Panel, Gages, and Console.

Did you complete the replacement?

Go to Step 10

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9

Important: Perform the setup procedure for the BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

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