GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Automatic Day-Night Mirrors System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Cover the ambient light sensor on the windshield side with a dark cloth.
  2. Shine a light on the headlamp sensor on the mirror side.
  3. Set the gear selector lever to the reverse position.
    • The mirror gradually darkens.
    • The mirror gradually lightens to a clear state.

2
  1. Set the gear selector lever to the park position.
  2. Remove the cloth and the light.
    • The mirror gradually darkens.
    • The mirror lightens to a clear state.

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