GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Interior Lights Dimming System Check

Interior Lights Dimming Diagnostic System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Install the scan tool.
  2. Turn the ignition switch to the ON position.
  3. Select BCM DTC with the scan tool.
  4. Check for any stored DTCs which may have an effect on serial data line communication.
  5. Turn ignition switch OFF.
  6. Remove the scan tool.

No DTCs are stored in memory.

Diagnostic System Check - Body Control System

2
  1. Turn the ignition switch to the ON position.
  2. Turn the I/P dimmer switch to the HIGH position.
  3. Turn the headlamp switch to the PARK position.

The following illumination lamps turn on inside the passenger compartment:

    • Radio faceplate.
    • Instrument cluster.
    • HVAC control head faceplate.
    • Fog lamp/rear compartment lid release switch (domestic) / fog lamp switch.
    • Electronic traction control and Ride Control (if equipped) switch faceplate.
    • MEMORY, MIRRORS, DOORLOCK, and WINDOW switch faceplate.
    • PRNDL.
    • Inside rearview mirror LED.

3
  1. Turn the I/P dimmer switch slowly to the LOW position.
  2. Return the I/P dimmer switch to the HIGH position.
    • The brightness of the I/P, radio, HVAC, doors, and PRNDL lamps slowly decrease.
    • The brightness of the I/P, radio, HVAC, doors, and PRNDL lamps slowly increase.

Instrument Panel Lamps Erratic with Dimmer Switch

4

Turn the headlamp switch to the OFF position.

The I/P lamps, HVAC, and radio illumination lamps turn OFF.

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