GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) 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

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the high beam indicator on the instrument cluster.

Does the indicator illuminate during the bulb check?

Go to Step 3

Go to Step 4

3

  1. Place the headlamp switch in the headlamps ON position.
  2. Place the headlamp dimmer switch in the HIGH BEAM position.

Does the indicator illuminate?

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

Go to Step 6

4

Inspect for poor connections at the harness connector of the instrument panel cluster (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 9

Go to Step 7

5

Test the headlamp high beam signal circuit for high resistance or open between the body control module (BCM) and the instrument panel (I/P) fuse block.

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 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 9

Go to Step 8

7

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

Did you complete the replacement?

Go to Step 9

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8

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 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 2