GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Jimmy - 2WD 🢒 Body and Accessories 🢒 Body Rear End 🢒 Interior Lights Dimming 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. Inspect for any stored DTCs that may affect the serial data line communication.
  5. Turn the ignition switch to the OFF position.
  6. Remove the scan tool.

No DTCs are stored in memory.

Go to applicable DTC table

2
  1. Turn the ignition switch to the ON position.
  2. Turn the IP dimmer switch to the HIGH position.
  3. Turn the headlamp switch to the PARK position.

The following components illuminate inside the passenger compartment:

    • The radio/steering wheel controls (utility)
    • The instrument cluster lamp
    • The rear wiper/washer and endgate/liftgate release switch (utility)
    • The HVAC control head faceplate lamp
    • The fog lamp switch
    • The rear window defogger switch (utility)
    • The transfer case select switch

3
  1. Turn the IP dimmer switch slowly to the LOW position.
  2. Return the IP dimmer switch to the HIGH position.
    • The brightness of the illuminated lamps slowly decreases.
    • The brightness of the illuminated lamps slowly increases.

Instrument Panel Lamps Inoperative

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