GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn ON the ignition.
  2. Place the transmission in neutral.
  3. Place the headlamp switch in the auto position.

(Day light conditions). DRL lamps on. All other exterior lamps off.

    • Headlamps on. Refer to Headlamps On in Daylight Conditions .
    • Parklamps on. Refer to Park Lamps Inoperative .
    •  Instrument panel on Refer to Instrument Panel Lamps Inoperative .

2

  1. Block the wheels.
  2. Turn ON the ignition.
  3. Set the park brake.
  4. Ensure the park brake is not set.
  5. Place the transmission in neutral.
  6. Place the headlamp switch in the auto position.

(Day light conditions). All exterior lamps off.

    • Headlamps on. Refer to Headlamps On in Daylight Conditions .
    • Parklamps on. Refer to Park Lamps Inoperative .
    • Instrument panel on. Refer to Instrument Panel Lamps Inoperative .

3

  1. Turn ON the ignition.
  2. Place the transmission in neutral.
  3. Place the headlamp switch in the auto position.
  4. Cover the ambient light sensor.

DRL lamps turn off. Headlamps and front and rear parklamps turn on.

    • Headlamps do not turn on. Refer to Headlamps Inoperative in Low Light Conditions .
    •  Parklamps do not turn on. Refer to Park Lamps Inoperative .

4

  1. Turn ON the ignition.
  2. Place the transmission in neutral.
  3. Place the headlamp switch in the auto position.
  4. Expose the ambient light sensor to a bright incandescent light.

After a few seconds all the exterior lamps turn off and the DRL lamps turn on.

    • Headlamps on. Refer to Headlamps On in Daylight Conditions .
    • Parklamps on. Refer to Park Lamps Inoperative .
    • Instrument panel on. Refer to Instrument Panel Lamps Inoperative .

5

  1. Turn ON the ignition.
  2. Turn the headlamp switch to the ON (head) position.

The headlamps turn ON. the DRL lamps turn OFF. The parklamps and the tail lamps turn ON.

    • Headlamps Refer to Daytime Running Lamps (DRL) Headlamps Inoperative .
    • Parklamps do not turn on. Refer to Park Lamps Inoperative .

6

  1. Turn ON the ignition.
  2. Turn the headlamp switch to the ON (head) position.
  3. Pull the dimmer switch toward the driver.

The headlamps turn ON. The DRL lamps turn OFF. The parklamps and the tail lamps turn ON. The headlamps switch from low beam to high beam.

    • Headlamps do not turn on. Refer to Daytime Running Lamps (DRL) Headlamps Inoperative .
    •  Headlamps do switch Intensity, both high beam and low beam on. Refer to Headlamps Do Not Switch Intensity .
    •  Parklamps do not turn on. Refer to Park Lamps Inoperative .