GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

1

Did you review the daytime running lamps (DRL) operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the headlamps.
  3. Turn ON the high beam headlamps.
  4. Turn OFF the headlamps.
  5. Set the park brake.
  6. Release the park brake.

Does the DRL system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Are the DRLs and the DRL indicator always ON?

Go to Step 5

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the DRL relay.
  3. Turn ON the ignition, with the engine OFF.

Are the DRL illuminated?

Go to Step 7

Go to Step 8

5

Test the DRL relay control circuit for a short to ground. 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 harness connector of the DRL control module. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

7

Repair the short to voltage in the headlamp low beam supply voltage circuit.

Did you complete the repair?

Go to Step 10

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8

Replace the DRL relay. Refer to Daytime Running Lamps (DRL) Relay Replacement .

Did you complete the replacement?

Go to Step 10

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9

Replace the DRL control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

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