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 Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Place the headlamp dimmer switch in the Flash-to-Pass position.

Do the high beam headlamps illuminate when the headlamp dimmer switch is in the Flash-to-Pass position?

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

Go to Step 3

3

  1. Turn the headlamp switch to the HEAD position.
  2. Place the headlamp dimmer switch in the HIGH position.

Do the high beam headlamps illuminate?

Go to Step 4

Go to Headlamps Inoperative - High Beams

4

  1. Disconnect connector C201.
  2. Probe the DRL control module flash-to-pass signal circuit at connector C201 with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

Test for a open or a high resistance in the headlamp high beam supply voltage circuit at the instrument panel cluster connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Inspect for a poor connection at the harness connection of the headlamp dimmer switch. 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

Repair an open or a high resistance in the DRL control module flash-to-pass signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

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8

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column.

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