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

  1. Expose the ambient light sensor to a bright incandescent lamp.
  2. Turn ON the ignition, with the engine OFF.
  3. Place the headlamp switch in the OFF position.
  4. Ensure the parking brake is disengaged.
  5. Block the wheels.
  6. Place the transaxle in neutral.

Do the daytime running lamps (DRL) illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Test the ground circuit of the DRL relay 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 6

Go to Step 4

4

Inspect for poor connections at the DRL relay. 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 6

Go to Step 5

5

Replace the DRL relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2