GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Firebird 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Daytime Running Lights (DRL) System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the headlamp switch OFF.
  2. Apply a bright light to the daytime running lamps (DRL) ambient light sensor.
  3. Turn the ignition to RUN.

The high beam headlamps turn on at a reduced intensity in approximately 30 seconds.

2

Cover the DRL ambient light sensor with a dark cloth.

The following conditions occur in approximately 15 seconds:

    • The high beam headlamps turn off.
    • The low beam headlamps turn on.
    • The exterior lamps turn on.

3
  1. Turn the ignition OFF.
  2. Apply the park brake.
  3. Apply a bright light to the DRL ambient light sensor.
  4. Turn the ignition to the RUN position.
    • The headlamps are off.
    • The exterior lamps are off.

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

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