GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

Turn the dimmer switch to the LOW position and the headlamp switch to the PARK position on the headlamp and the instrument panel (IP) lamp dimmer switch.

    • The following components are activated:
       - The steering wheel radio control switches
       - The headlamp switch
       - The door lock switches
       - The window switches
       - The heater and A/C control
       - The instrument cluster
       - The ashtray lamp
       - The interior lamp
       - The multi-function switches
       - The rear window wiper/washer
       - The multi-function switches
       - The driver information switch
       - The rear door latch release actuator
    • The following vacuum fluorescent (VF) displays step dim:
      • The radio display
      • The radio rear seat audio control display
      • The driver information display
      • The instrument cluster display

Refer to Instrument Panel Lamps or Vacuum Fluorescent Displays Inoperative

Refer to Instrument Panel Lamps Inoperative - One

Refer to Vacuum Fluorescent Display Do Not Dim with Park Lamps On

Refer to Radio Switch Illumination Inoperative

2

Turn the dimmer switch slowly to the HIGH position on the headlamp and the IP dimmer switch.

    • The brightness of the IP lamps slowly increase to HIGH.
    • The brightness of the VF displays slowly increase to HIGH.

Refer to Instrument Panel Lamps Erratic with Dimmer Switch

Refer to Vacuum Fluorescent Displays Do Not Change Intensity - All

3

  1. Turn the dimmer switch to the OFF position.
  2. Turn the park lamp switch to the OFF position.
    • The IP lamps turn to the OFF position.
    • The VF displays turn to the OFF position.

Refer to Instrument Panel Lamps Erratic with Dimmer Switch

Refer to Vacuum Fluorescent Displays Do Not Change Intensity - All

*Refer to appropriate Symptom Diagnosis for the applicable results.