Jeep 1996 Grand Cherokee Service Manual page 311

8E - 14 INSTRUMENT PANEL SYSTEMS
DIAGNOSIS AND TESTING (Continued)
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
REFER TO GROUP 8M - PASSIVE RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL COM-
PONENT 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 inopera-
tive, replace the faulty bulbs. If all of the illumina-
tion lamps are inoperative, proceed as follows.
(1) Disconnect and isolate the battery negative
cable. Remove the GDM as described in this group.
Unplug the GDM connector and 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 con-
nector. 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) connector. Check for continuity between the
panel lamp driver circuit cavities of the GDM connec-
tor and the BCM connector. If OK, refer to Group 8L
- Lamps for diagnosis of the headlamp switch and/or
the proper Body Diagnostic Procedures Manual for
diagnosis of the BCM. If not OK, repair the open cir-
cuit as required.
FOUR-WHEEL DRIVE INDICATOR LAMPS
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
REFER TO GROUP 8M - PASSIVE RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL COM-
PONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Unplug the connector at the transfer case
switch. Check for continuity between the ground cir-
cuit cavity of the transfer case switch connector and
a good ground. There should be continuity. If OK, go
to Step 2. If not OK, repair the open circuit as
required.
(2) Check the transfer case switch continuity while
shifting the transfer case shift lever to the proper
positions. The switch continuity should be as shown
in (Fig. 1). If OK, go to Step 3. If not OK, replace the
faulty switch.
Fig. 1 Transfer Case Switch
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