Grand Cherokee 4WD V8-5.2L VIN Y (1998)
Driver/Vehicle Information Display: Testing and Inspection
Graphic Display Module
If the problem being diagnosed is related to Graphic Display Module (GDM) illumination, see the GDM Illumination diagnosis below. If the problem
being diagnosed is related to the four-wheel drive display or the four-wheel drive message lamps, refer to Four-Wheel Drive Indicator Lamp diagnosis.
See: Instrument Panel, Gauges and Warning Indicators/Four-Wheel Drive (4WD) Indicator Lamp/Testing and Inspection/Component Tests and General
Diagnostics
GDM Illumination
The diagnosis found here addresses an inoperative graphic display module illumination lamp condition. If the problem being diagnosed is related to
the dimming level of the illumination lamps, diagnosis should be performed with a DRB scan tool as described in the proper Diagnostic Procedures.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIRBAG SYSTEMS BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
If only individual illumination lamps are inoperative, replace the faulty bulbs. If all of the illumination lamps are inoperative, proceed as follows:
1. Disconnect and isolate the battery negative cable. Remove the GDM from the instrument panel. Unplug the GDM wire harness connector. Connect
the battery negative cable.
2. Turn the park lamps on with the headlamp switch. Adjust the panel lamp dimmer switch knob to its highest level (fully upwards). Check for
voltage at the panel lamp driver circuit cavity of the GDM wire harness connector. If OK, replace the faulty GDM. If not OK, go to Step 3.
3. Disconnect and isolate the battery negative cable. Unplug the white 24-way Body Control Module (BCM) wire harness connector. Check for
continuity between the panel lamp driver circuit cavities of the GDM wire harness connector and the BCM wire harness connector. If OK, refer to
Lighting and Horns/Lamps for diagnosis of the headlamp switch and/or the proper Diagnostic Procedures for diagnosis of the BCM. If not OK,
repair the open circuit as required.
