GM Service Manual Online
For 1990-2009 cars only

Automatic Day-Night Mirrors System Check W/ IGN and Mirror Switch Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Place the ignition switch in the RUN position.
  2. Place the shift lever in the PARK position.
  3. Place the mirror switch in the MAX position.
  4. Cover the ambient light sensor (windshield side) with a dark cloth.
  5. Shine a light on the headlamp sensor (mirror side).

The following mirrors gradually darken:

    • The inside rear view mirror
    • The left outside mirror (Buick)

2

Place the shift lever in the REVERSE position.

The mirror(s) gradually lighten(s) to a clear state.

Mirrors - Automatic Day-Night Inoperative in Reverse

3

Place the gear selector lever into the PARK position.

The mirror(s) gradually darken(s).

4

Remove the cloth and the light.

The mirror(s) gradually lighten(s) to a clear state.

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

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Cover the ambient light sensor (windshield side) with a dark cloth.
  2. Shine a light on the headlamp sensor (mirror side).
  3. Set the gear selector lever to the REVERSE position.
  1. The mirror gradually darkens.
  2. The mirror gradually lightens to a clear state.
  1. Go to Outside Mirrors Automatic Day-Night Feature Inoperative .
  2. Go to Mirrors - Automatic Day-Night Inoperative in Reverse .

2

  1. Set the gear selector lever to the PARK position.
  2. Remove the cloth and the light.
  1. The mirror gradually darkens.
  2. The mirror gradually lightens to a clear state.
  1. Go to Outside Mirrors Automatic Day-Night Feature Inoperative .
  2. Go to Mirrors - Automatic Day-Night Inoperative in Reverse .

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

Automatic Day-Night Mirrors System Check W/O IGN and Mirror Switch Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Cover the ambient light sensor (windshield side) with a dark cloth.
  2. Shine a light on the headlamp sensor (mirror side).
  3. Set the gear selector lever to the REVERSE position.
  1. The mirror gradually darkens.
  2. The mirror gradually lightens to a clear state.
  1. Go to Outside Mirrors Automatic Day-Night Feature Inoperative .
  2. Go to Mirrors - Automatic Day-Night Inoperative in Reverse .

2

  1. Set the gear selector lever to the PARK position.
  2. Remove the cloth and the light.
  1. The mirror gradually darkens.
  2. The mirror gradually lightens to a clear state.
  1. Go to Outside Mirrors Automatic Day-Night Feature Inoperative .
  2. Go to Mirrors - Outside Automatic Day-Night Inoperative .

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