Jeep 1997 Grand Cherokee Service Manual page 418

8E - 16 INSTRUMENT PANEL SYSTEMS
DIAGNOSIS AND TESTING (Continued)
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE RESTRAINT
SYSTEMS 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 POSSI-
BLE PERSONAL INJURY.
If the low fuel warning lamp fails to light during
the bulb test (about four seconds after the ignition
switch is turned to the On position), replace the low
fuel warning lamp bulb with a known good unit. If
the indicator lamp still fails to operate, diagnosis of
the lamp, the instrument cluster circuitry, the CCD
data bus, or the Body Control Module (BCM) should
be performed with a DRB scan tool as described in
the proper Body Diagnostic Procedures manual.
Diagnosis of the fuel gauge sending unit and circuit
or the Powertrain Control Module (PCM) should be
performed with a DRB scan tool as described in the
proper Powertrain Diagnostic Procedures manual.
MALFUNCTION INDICATOR LAMP
The diagnosis found here addresses an inoperative
malfunction indicator (Check Engine) lamp condition.
If the lamp comes on and stays on with the engine
running, refer to Group 14 - Fuel Systems for diag-
nosis. For circuit descriptions and diagrams, refer to
8W-40 - Instrument Cluster in Group 8W - Wiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE RESTRAINT
SYSTEMS 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 POSSI-
BLE PERSONAL INJURY.
If the malfunction indicator lamp fails to light dur-
ing the bulb test (about three seconds after the igni-
tion switch is turned to the On position), replace the
malfunction indicator lamp bulb with a known good
unit. If the indicator lamp still fails to operate, diag-
nosis of the lamp, the instrument cluster circuitry, or
the CCD data bus should be performed with a DRB
scan tool as described in the proper Body Diagnostic
Procedures manual. Diagnosis of the Powertrain Con-
trol Module (PCM) should be performed with a DRB
scan tool as described in the proper Powertrain Diag-
nostic Procedures manual.
MASTER LIGHTING INDICATOR LAMP
The master lighting indicator shares the same cir-
cuitry as the cluster illumination lamps, and will
brighten and dim when the panel lamp dimmer
switch is adjusted.
addresses an inoperative master lighting indicator
lamp condition. If the problem being diagnosed is
related to the dimming level of the master lighting
indicator lamp, diagnosis should be performed with a
DRB scan tool as described in the proper Body Diag-
nostic Procedures manual. For circuit descriptions
and diagrams, refer to 8W-40 - Instrument Cluster,
8W-45 - Body Control Module, and/or 8W-50 - Front
Lighting in Group 8W - Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE RESTRAINT
SYSTEMS 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 POSSI-
BLE PERSONAL INJURY.
If only the master lighting indicator lamp is inop-
erative, replace the faulty bulb. If all of the cluster
illumination lamps are inoperative, proceed as fol-
lows.
(1) Disconnect and isolate the battery negative
cable. Remove the cluster bezel and the cluster
assembly as described in this group.
(2) Connect the battery negative cable and 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 cluster wire harness
connector. If OK, replace the faulty instrument clus-
ter. 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
cluster wire harness connector and the BCM wire
harness connector. If OK, refer to Group 8L - Lamps
for diagnosis of the headlamp switch and/or the
proper Body Diagnostic Procedures manual for diag-
nosis of the BCM. If not OK, repair the open circuit
as required.
SEAT BELT REMINDER LAMP
The diagnosis found here addresses an inoperative
seat belt reminder lamp condition. If the lamp comes
on and flashes following its display function (for
about seven seconds after the ignition switch is
turned to the On position), refer to the diagnosis for
the airbag indicator lamp in this group. For circuit
descriptions and diagrams, refer to 8W-40 - Instru-
ment Cluster in Group 8W - Wiring Diagrams.
The diagnosis found
ZG
here