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

2

  1. Place the headlamp switch in the OFF position.
  2. Expose the ambient light sensor to a bright incandescent light.
  3. Turn ON the ignition, with the engine OFF.
  4. Ensure the parking brake is disengaged.
  5. With the brake pedal pressed, place the gear selector in the REVERSE position.

Does the daytime running lamps (DRL) indicator illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are the DRL illuminated?

Go to Step 4

Go to Diagnostic System Check - Vehicle

4

With a scan tool, select Instrument Panel Cluster (IPC), Special Functions, Lamp and Gauge Test, turn ON the IPC lamps.

Does the DRL indicator illuminate?

Go to Step 7

Go to Step 5

5

Check for a burned filament in the DRL indicator bulb.

Is the bulb OK?

Go to Step 6

Go to Step 8

6

Inspect for poor connections at the harness connector of the IPC harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

Inspect for poor connections at the harness connector of the body control module (BCM) harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Replace the bulb. Refer to Instrument Cluster Bulb Replacement .

Did you complete the replacement?

Go to Step 11

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9

Replace the IPC. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

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10

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3