GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Results

Abnormal Result(s)*

1

  1. Turn the light switch to the HEAD position.
  2. Move the dimmer switch to the LO position.

The left and the right low beam filaments illuminate at the normal low beam intensity.

Headlamps Inoperative - Low Beams

2

Move the dimmer switch forward to the HI position.

    • The left and the right low beam filaments turn OFF.
    • The high beam filaments remain illuminated.
    • The high beam indicator is illuminated

Headlamps Inoperative - High Beams

3

  1. Turn the light switch to the OFF position or to the PARK position.
  2. Start the engine.
  3. Disengage the parking brake.
    • Both low beam filaments of the DRL indicator remain illuminated.
    • The left and the right low beam filaments illuminate to 80 percent of full intensity.
    • The DRL indicator is lit.

4

  1. Shut the engine OFF.
  2. Engage the parking brake.

All the headlamps turn OFF.

Daytime Running Lamps (DRL) Headlamps Always On

5

  1. Engage the parking brake.
  2. Turn the ignition to the ON position.

All the headlamps stay OFF.

Headlamps, Daytime Running Lamps (DRL) On With Park Brake Applied

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.