GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

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

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn OFF the twilight sentinel delay.
  3. Observe the headlamp lights ON indicator.
  4. Turn ON and OFF the headlamps.

Does the headlamp lights ON indicator operate properly?

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

Go to Step 3

3

Do the headlamps operate properly?

Go to Step 4

Go to Headlamps Inoperative - Low Beams

4

  1. Turn OFF the ignition.
  2. Disconnect the dash integration module (DIM).
  3. Connect a 3-amp fused jumper between the LED dimming signal circuit of the headlamp lights ON indicator and a good ground.
  4. Turn ON the ignition, with the engine OFF.

Does the lights ON indicator illuminate?

Go to Step 8

Go to Step 5

5

Test the positive battery voltage circuit of the headlamp lights ON indicator for an open, high resistance or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Test the LED dimming signal circuit for an open or short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Inspect for poor connections at the harness connector of the headlamp 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 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the DIM. 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 11

Go to Step 10

9

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 11

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10

Important:: After replacement perform the setup procedure for the DIM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the DIM. Refer to Dash Integration Module Replacement in Body Control System.

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 2