GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1998 🢒 LSS 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Headlight System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the ignition switch to the OFF position.
  2. Place the twilight sentinel switch in the OFF position.
  3. Place the headlamp switch in the OFF position.

All of the exterior lamps are off.

2

Place the headlamp switch in the PARK position.

All of the park lamps turn on.

Exterior Lights System Check

3
  1. Place the headlamp switch in the ON position.
  2. Place the headlamp dimmer switch in the LOW position.
    • All of the parklamps remain on.
    • Both of the low beam headlamps light.

4

Place the headlamp dimmer switch in the HIGH position.
    • All of the park lamps remain on.
    • The headlamps switch from low beams to high beams.

5
  1. Place the headlamp dimmer switch in the LOW position.
  2. Place the headlamp switch in the OFF position.
  3. Turn the ignition switch to the RUN position.
  4. Shine a bright light (not fluorescent) on the ambient light sensor.
  5. Place the gear selector in the DRIVE position.
    • The Buick model has the following normal results:
       - Both of the high beam headlamps light at the reduced intensity.
       - The park lamps are off.
    • The Oldsmobile/Pontiac model has the following normal results:
       - Both of the low beam headlamps light at the reduced intensity.
       - The park lamps are off.

6
  1. Place the gear selector in the PARK position.
  2. Turn the ignition switch to the RUN position.

    3. Place the twilight sentinel switch in the MIN position.

  3. Cover the ambient light sensor.

The following components at full intensity light within 30 seconds:

    • All of the park lamps
    • Both low beam headlamps

7
  1. Place the twilight sentinel switch in the MAX position.
  2. Turn the ignition switch to the OFF position.

All of the exterior lamps turn off after approximately 3 minutes.

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