wire ground JEEP GRAND CHEROKEE 2002 WJ / 2.G Repair Manual

(3) While still holding the odometer/trip odometer
switch button depressed, turn the ignition switch to
the On position, but do not start the engine.
(4) Release the odometer/trip odometer switch but-
ton.
(5) The instrument cluster will automatically
begin the actuator test sequence, as follows:
(a) The cluster will turn on, then off again each
of the PCI data bus message controlled indicators
(except Airbag) to confirm the functionality of the
indicator and the cluster control circuitry:
(b) The cluster will sweep the needles for each of
the gauges from minimum to maximum and back
to minimum to confirm the functionality of the
gauge and the cluster control circuitry:
(c) Only on models with a premium version of
the cluster, the cluster will illuminate the electro-
luminescent lamp and turn it off again to confirm
the functionality of the lamp and the cluster con-
trol circuitry.
(d) The cluster will sequentially step the odome-
ter/trip odometer VFD display from all zeros
(000000) through all nines (999999) to confirm the
functionality of all VFD segments and their control
circuitry, then display the software version number,
followed by ªDONEº.
(6) The actuator test is now completed. The instru-
ment cluster will automatically exit the self-diagnos-
tic mode and return to normal operation at the
completion of the test, if the ignition switch is turned
to the Off position during the test, or if a vehicle
speed message indicating that the vehicle is moving
is received from the PCM over the PCI data bus dur-
ing the test.
(7) Go back to Step 1 to repeat the test, if
required.
CLUSTER ILLUMINATION DIAGNOSIS
On models equipped with a base version of the
instrument cluster, the EMIC has several incandes-
cent illumination lamps that are illuminated when-
ever the exterior lighting is turned On. If the
problem being diagnosed is a single inoperative illu-
mination lamp, be certain that the bulb and bulb
holder unit are properly installed in the instrument
cluster electronic circuit board. If no installation
problems are found replace the faulty bulb and bulb
holder unit. If all of the cluster illumination lamps
are inoperative, the most reliable, efficient, and accu-
rate means to diagnose the cluster illumination func-tion of the instrument cluster requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: ON VEHICLES EQUIPPED WITH THE
PREMIUM INSTRUMENT CLUSTER, THE CLUSTER
CIRCUITRY PROVIDES AN ALTERNATING CURRENT
TO SUPPLY POWER TO THE ELECTRO-LUMINES-
CENT ILLUMINATION LAMP THROUGH A PIGTAIL
WIRE AND CONNECTOR THAT IS ACCESSIBLE AT
THE BACK OF THE CLUSTER HOUSING. USE
PROPER PRECAUTIONS WHEN HANDLING THIS
UNIT DURING DIAGNOSIS OR SERVICE TO AVOID
ELECTRICAL SHOCK AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(3) Remove the two screws that secure the upper
mounting tabs of the instrument cluster to the
underside of the instrument cluster hood formation of
the instrument panel top pad.
(4) Remove the two screws that secure the lower
mounting tabs of the instrument cluster to the
instrument panel structural duct.
WJINSTRUMENT CLUSTER 8J - 9
INSTRUMENT CLUSTER (Continued)

(5) Pull the upper mounting tabs of the instrument
cluster downward, then pull the instrument cluster
rearward far enough to access the instrument panel
wire harness connector for the instrument cluster
(Fig. 3).
(6) Disconnect the instrument panel wire harness
connector for the instrument cluster from the connec-
tor receptacle on the back of the instrument cluster
housing.
(7) Remove the instrument cluster from the instru-
ment panel.
DISASSEMBLY
Some of the components for the instrument cluster
used in this vehicle are serviced individually. The
serviced components include: the incandescent
instrument cluster indicator and illumination lamp
bulbs (including the integral bulb holders), the clus-
ter lens, hood and mask unit, and the cluster housing
rear cover. Following are the procedures for disas-
sembling these components from the instrument clus-
ter unit.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: ON VEHICLES EQUIPPED WITH THE
PREMIUM INSTRUMENT CLUSTER, THE CLUSTER
CIRCUITRY PROVIDES AN ALTERNATING CURRENT
TO SUPPLY POWER TO THE ELECTRO-LUMINES-
CENT ILLUMINATION LAMP THROUGH A PIGTAIL
WIRE AND CONNECTOR THAT IS ACCESSIBLE AT
THE BACK OF THE CLUSTER HOUSING. USE
PROPER PRECAUTIONS WHEN HANDLING THIS
UNIT DURING DIAGNOSIS OR SERVICE TO AVOID
ELECTRICAL SHOCK AND POSSIBLE PERSONAL
INJURY.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp or indicator bulb and bulb
holder units. However, the illumination lamps and
the indicators use different bulb and bulb holder unit
sizes. They must never be interchanged. Be certain
that any bulb holder removed from the electronic cir-
cuit board is reinstalled in the correct position.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) Turn the bulb holder counterclockwise about
sixty degrees on the cluster electronic circuit board
(Fig. 4).
(4) Pull the bulb and bulb holder straight back to
remove it from the bulb mounting hole in the cluster
electronic circuit board.
CLUSTER LENS, HOOD AND MASK
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) Work around the perimeter of the cluster hous-
ing to disengage each of the eight latches that secure
the cluster lens, hood and mask unit to the cluster
housing (Fig. 5).
(4) Gently pull the cluster lens, hood and mask
unit away from the cluster housing.
CLUSTER HOUSING REAR COVER
(1) Disconnect and isolate the battery negative
cable.
Fig. 3 Instrument Cluster Remove/Install
1 - INSTRUMENT PANEL WIRE HARNESS CONNECTOR
2 - INSTRUMENT CLUSTER
8J - 10 INSTRUMENT CLUSTERWJ
INSTRUMENT CLUSTER (Continued)

(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).(3) On models with a premium cluster only, discon-
nect the electro-luminescent illumination lamp pig-
tail wire connector from the receptacle on the cluster
electronic circuit board and disengage the pigtail
wire from the integral routing clip on the rear cover
(Fig. 6).
(4) Remove the seven screws that secure the rear
cover to the back of the cluster housing.
(5) Disengage the eight latch features (four on top,
four on the bottom) that secure the upper and lower
edges of the rear cover to the top and bottom of the
cluster housing.
(6) Remove the rear cover from the back of the
cluster housing.
ASSEMBLY
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
Fig. 4 Cluster Bulb Locations - Typical
1 - ILLUMINATION LAMP BULBS AND HOLDERS (5)
2 - CLUSTER HOUSING REAR COVER
3 - CLUSTER HOUSING
Fig. 5 Instrument Cluster Components
1 - MINOR GAUGE SETS
2 - HOUSING REAR COVER
3 - TRIP ODOMETER RESET KNOB
4 - LENS, HOOD AND MASK
5 - MAJOR GAUGES
6 - CLUSTER HOUSING
Fig. 6 Cluster Housing Rear Cover Screws
1 - ELECTRO-LUMINESCENT LAMP PIGTAIL WIRE
CONNECTOR
2 - REAR COVER
3 - SCREW (7)
WJINSTRUMENT CLUSTER 8J - 11
INSTRUMENT CLUSTER (Continued)

WARNING: ON VEHICLES EQUIPPED WITH THE
PREMIUM INSTRUMENT CLUSTER, THE CLUSTER
CIRCUITRY PROVIDES AN ALTERNATING CURRENT
TO SUPPLY POWER TO THE ELECTRO-LUMINES-
CENT ILLUMINATION LAMP THROUGH A PIGTAIL
WIRE AND CONNECTOR THAT IS ACCESSIBLE AT
THE BACK OF THE CLUSTER HOUSING. USE
PROPER PRECAUTIONS WHEN HANDLING THIS
UNIT DURING DIAGNOSIS OR SERVICE TO AVOID
ELECTRICAL SHOCK AND POSSIBLE PERSONAL
INJURY.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp or indicator bulb and bulb
holder units. However, the illumination lamps and
the indicators use different bulb and bulb holder unit
sizes. They must never be interchanged.
CAUTION: Be certain that any bulb and bulb holder
unit removed from the cluster electronic circuit
board is reinstalled in the correct position. Always
use the correct bulb size and type for replacement.
An incorrect bulb size or type may overheat and
cause damage to the instrument cluster, the elec-
tronic circuit board and/or the gauges.
(1) Insert the bulb and bulb holder straight into
the correct bulb mounting hole in the cluster elec-
tronic circuit board (Fig. 4).
(2) With the bulb holder fully seated against the
cluster electronic circuit board, turn the bulb holder
clockwise about sixty degrees to lock it into place.
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
CLUSTER LENS, HOOD AND MASK
(1) Position the cluster lens, hood and mask unit
over the face of the instrument cluster (Fig. 5). Be
certain that the odometer/trip odometer switch but-
ton is inserted through the proper clearance holes in
the mask and the lens.
(2) Press firmly and evenly on the cluster lens,
hood and mask unit to install it onto the cluster
housing.
(3) Work around the perimeter of the cluster hous-
ing to be certain that each of the eight latches that
secure the cluster lens, hood and mask unit to the
cluster housing is fully engaged.
(4) Reinstall the instrument cluster into the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(5) Reconnect the battery negative cable.CLUSTER HOUSING REAR COVER
(1) Position the rear cover onto the back of the
cluster housing (Fig. 6).
(2) Press firmly and evenly on the rear cover until
each of the eight latches (four on top, four on the bot-
tom) that secure the upper and lower edges of the
rear cover to the top and bottom of the cluster hous-
ing are fully engaged.
(3) Install and tighten the seven screws that
secure the rear cover to the back of the cluster hous-
ing. Tighten the screws to 2 N´m (20 in. lbs.).
(4) On models with a premium cluster only, recon-
nect the electro-luminescent illumination lamp pig-
tail wire connector to the receptacle on the cluster
electronic circuit board and engage the pigtail wire
under the integral routing clip on the rear cover.
(5) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(6) Reconnect the battery negative cable.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: ON VEHICLES EQUIPPED WITH THE
PREMIUM INSTRUMENT CLUSTER, THE CLUSTER
CIRCUITRY PROVIDES AN ALTERNATING CURRENT
TO SUPPLY POWER TO THE ELECTRO-LUMINES-
CENT ILLUMINATION LAMP THROUGH A PIGTAIL
WIRE AND CONNECTOR THAT IS ACCESSIBLE AT
THE BACK OF THE CLUSTER HOUSING. USE
PROPER PRECAUTIONS WHEN HANDLING THIS
UNIT DURING DIAGNOSIS OR SERVICE TO AVOID
ELECTRICAL SHOCK AND POSSIBLE PERSONAL
INJURY.
(1) Position the instrument cluster to the instru-
ment panel.
8J - 12 INSTRUMENT CLUSTERWJ
INSTRUMENT CLUSTER (Continued)

(2) Reconnect the instrument panel wire harness
connector for the instrument cluster to the connector
receptacle on the back of the instrument cluster
housing (Fig. 7).
(3) Position the lower mounting tabs of the instru-
ment cluster to the mounting holes on the instru-
ment panel structural duct, then tilt the top of the
instrument cluster forward until the upper mounting
tabs are positioned to the mounting holes on the
underside of the instrument cluster hood formation of
the instrument panel top pad.
(4) Install and tighten the two screws that secure
the upper mounting tabs of the instrument cluster to
the underside of the instrument cluster hood forma-
tion of the instrument panel top pad. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(5) Install and tighten the two screws that secure
the lower mounting tabs of the instrument cluster to
the instrument panel structural duct. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(6) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(7) Reconnect the battery negative cable.
ABS INDICATOR
DESCRIPTION
An Anti-lock Brake System (ABS) indicator is stan-
dard equipment on all instrument clusters. The ABS
indicator is located on the lower left edge of the
instrument cluster, to the left of the tachometer. TheABS indicator consists of a International Control and
Display Symbol icon for ªFailure of Anti-lock Braking
Systemº imprinted on an amber lens. The lens is
located behind a cutout in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. The icon appears
silhouetted against an amber field through the trans-
lucent outer layer of the overlay when the indicator
is illuminated from behind by a replaceable incandes-
cent bulb and bulb holder unit located on the instru-
ment cluster electronic circuit board. The ABS
indicator lens is serviced as a unit with the instru-
ment cluster lens, hood and mask unit.
OPERATION
The ABS indicator gives an indication to the vehi-
cle operator when the ABS system is faulty or inop-
erative. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the Controller Anti-lock Brake
(CAB) over the Programmable Communications
Interface (PCI) data bus. The ABS indicator bulb is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the indicator will
always be off when the ignition switch is in any posi-
tion except On or Start. The bulb only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the ABS indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the CAB sends an elec-
tronic ABS lamp-on message to the cluster which will
illuminate the ABS indicator for about four seconds
as a bulb test. The entire four second bulb test is a
function of the CAB.
²ABS Indicator Lamp-On Message- Each time
the cluster receives an ABS indicator lamp-on mes-
sage from the CAB, the ABS indicator will be illumi-
nated. The indicator remains illuminated until the
cluster receives an ABS indicator lamp-off message
from the CAB, or until the ignition switch is turned
to the Off position, whichever occurs first.
²Communication Error- If the cluster receives
no ABS indicator lamp-on or lamp-off messages from
the CAB for six consecutive seconds, the ABS indica-
tor is illuminated. The indicator remains illuminated
until the cluster receives a valid lamp-on or lamp-off
message from the CAB, or until the ignition switch is
turned to the Off position, whichever occurs first.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the ABS indica-
Fig. 7 Instrument Cluster Remove/Install
1 - INSTRUMENT PANEL WIRE HARNESS CONNECTOR
2 - INSTRUMENT CLUSTER
WJINSTRUMENT CLUSTER 8J - 13
INSTRUMENT CLUSTER (Continued)

Diagnostic Trouble Code (DTC) for any malfunction it
detects. Each time the airbag indicator fails to illu-
minate due to an open or short in the cluster airbag
indicator circuit, the cluster sends a message notify-
ing the ACM of the condition, then the instrument
cluster and the ACM will each store a DTC. For
proper diagnosis of the airbag system, the ACM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the airbag indicator,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
BRAKE/PARK BRAKE
INDICATOR
DESCRIPTION
A brake indicator is standard equipment on all
instrument clusters. The brake indicator is located
near the left edge of the instrument cluster, to the
left of the tachometer. There are two versions of the
brake indicator. The version used depends upon the
market for which the vehicle is manufactured. The
version of the brake indicator used for vehicles man-
ufactured for the United States consists of the word
ªBRAKEº imprinted on a red lens. The Rest-Of-World
(ROW) market version of this indicator has two
International Control and Display Symbol icons
imprinted on the red lens; one is the icon for ªBrake
Failureº, and the other is the icon for ªParking
Brakeº. In either case, the lens is located behind a
cutout in the opaque layer of the instrument cluster
overlay. The dark outer layer of the overlay prevents
the indicator from being clearly visible when it is not
illuminated. The ªBRAKEº text or the two icons
appear silhouetted against a red field through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by a Light Emitting
Diode (LED), which is soldered onto the instrument
cluster electronic circuit board. The brake indicator
lens is serviced as a unit with the instrument cluster
lens, hood and mask unit.
OPERATION
The brake indicator gives an indication to the vehi-
cle operator when the parking brake is applied, when
the fluid level of the brake hydraulic system is low,
or if there are certain malfunctions of the Anti-lock
Brake System (ABS). This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon cluster programming, electronic
messages received by the cluster from the Controller
Anti-lock Brake (CAB) over the Programmable Com-
munications Interface (PCI) data bus, and a hard
wired input to the cluster from the park brake
switch. The brake indicator Light Emitting Diode(LED) is completely controlled by the instrument
cluster logic circuit, and that logic will only allow
this indicator to operate when the instrument cluster
receives a battery current input on the fused ignition
switch output (run-start) circuit. Therefore, the indi-
cator will always be off when the ignition switch is in
any position except On or Start. The LED only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the brake indicator for the following rea-
sons:
²Bulb Test- Each time the ignition switch is
turned to the On position the brake indicator is illu-
minated by the instrument cluster for about three
seconds as a bulb test.
²Brake Indicator Lamp-On Message- Each
time the cluster receives a brake indicator lamp-on
message from the CAB, the brake indicator will be
illuminated. The indicator remains illuminated until
the cluster receives a brake indicator lamp-off mes-
sage from the CAB.
²Park Brake Switch Input- Each time the
cluster logic circuit detects ground on the park brake
switch sense circuit (park brake switch closed = park
brake applied or not fully released) the brake indica-
tor is illuminated. The indicator remains illuminated
until the park brake switch sense input to the cluster
is an open circuit (park brake switch open = park
brake fully released), or until the ignition switch is
turned to the Off position, whichever occurs first.
²Communication Error- If the cluster receives
no brake indicator lamp-on or lamp-off messages
from the CAB for six consecutive seconds, the brake
indicator is illuminated. The indicator remains illu-
minated until the cluster receives a single valid
brake indicator lamp-off message from the CAB.
²Actuator Test- Each time the cluster is put
through the actuator test, the brake indicator will be
turned on for the duration of the test to confirm the
functionality of the LED and the cluster control cir-
cuitry.
The park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the red
brake warning indicator driver circuit whenever the
park brake is applied or not fully released. The CAB
continually monitors the input from the brake fluid
level switch and the circuits of the anti-lock brake
system, then sends the proper brake indicator
lamp-on or lamp-off messages to the instrument clus-
ter. If the CAB sends a brake indicator lamp-on mes-
sage after the bulb test, it indicates that the CAB
has detected a brake hydraulic system malfunction
and/or that the ABS system has become inoperative.
The CAB will store a Diagnostic Trouble Code (DTC)
for any malfunction it detects.
WJINSTRUMENT CLUSTER 8J - 15
AIRBAG INDICATOR (Continued)

For further diagnosis of the brake indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). The park
brake switch input to the instrument cluster can be
diagnosed using conventional diagnostic tools and
methods. For proper diagnosis of the brake fluid level
switch input to the CAB, the anti-lock brake system,
the CAB, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the
brake indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - BRAKE INDICATOR
The diagnosis found here addresses an inoperative
park brake indicator condition. If there are problems
with several indicators in the instrument cluster,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). If the brake
indicator stays on with the ignition switch in the On
position and the park brake released, or comes on
while driving, (Refer to 5 - BRAKES - DIAGNOSIS
AND TESTING). If no brake system problem is
found, the following procedures will help to locate a
shorted or open circuit, or a faulty park brake switch
input. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
INDICATOR ILLUMINATES DURING BULB TEST, BUT DOES
NOT WHEN PARK BRAKE APPLIED
(1) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the park brake switch from the switch
terminal. Apply the parking brake. Check for conti-nuity between the park brake switch terminal and a
good ground. There should be continuity. If OK, go to
Step 2. If not OK, replace the faulty park brake
switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the red brake warning indicator driver circuit cavi-
ties of the instrument panel wire harness connector
for the park brake switch and the instrument panel
wire harness connector for the instrument cluster.
There should be continuity. If not OK, repair the
open red brake warning indicator driver circuit
between the park brake switch and the instrument
cluster as required.
INDICATOR REMAINS ILLUMINATED - BRAKE SYSTEM
CHECKS OK
(1) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the park brake switch from the park
brake switch terminal. Check for continuity between
the terminal of the park brake switch and a good
ground. There should be no continuity with the park
brake released, and continuity with the park brake
applied. If OK, go to Step 2. If not OK, replace the
faulty park brake switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the red brake warning indicator driver circuit cavity
of the instrument panel wire harness connector for
the park brake switch and a good ground. There
should be no continuity. If not OK, repair the shorted
red brake warning indicator driver circuit between
the park brake switch and the instrument cluster as
required.
CHECK GAUGES INDICATOR
DESCRIPTION
A check gauges indicator is standard equipment on
all instrument clusters. The check gauges indicator is
located on the right edge of the instrument cluster, to
the right of the speedometer. The check gauges indi-
cator consists of the words ªCHECK GAGESº
imprinted on a red lens. The lens is located behind a
cutout in the opaque layer of the instrument cluster
overlay. The dark outer layer of the overlay prevents
the indicator from being clearly visible when it is not
illuminated. The ªCHECK GAGESº text appears sil-
houetted against a red field through the translucent
outer layer of the overlay when the indicator is illu-
minated from behind by a Light Emitting Diode
(LED), which is soldered onto the instrument cluster
electronic circuit board. The check gauges indicator
8J - 16 INSTRUMENT CLUSTERWJ
BRAKE/PARK BRAKE INDICATOR (Continued)

then sends the proper rear fog lamp indicator
lamp-on and lamp-off messages to the instrument
cluster. If the rear fog lamp indicator fails to light
during the actuator test, replace the bulb with a
known good unit. For further diagnosis of the rear
fog lamp indicator or the instrument cluster circuitry
that controls the indicator, (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the rear fog lamp
system, the BCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the rear fog lamp indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
SEATBELT INDICATOR
DESCRIPTION
A seatbelt indicator is standard equipment on all
instrument clusters. The seatbelt indicator is located
near the lower edge of the instrument cluster, to the
left of the tachometer. The seatbelt indicator consists
of an International Control and Display Symbol icon
for ªSeat Beltº imprinted on a red lens. The lens is
located behind a cutout in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the icon from being clearly vis-
ible when the indicator is not illuminated. The icon
appears silhouetted against a red field through the
translucent outer layer of the overlay when it is illu-
minated from behind by a Light Emitting Diode
(LED), which is soldered onto the instrument cluster
electronic circuit board. The seatbelt indicator lens is
serviced as a unit with the instrument cluster lens,
hood and mask unit.
OPERATION
The seatbelt indicator gives an indication to the
vehicle operator of the status of the driver side front
seatbelt. This indicator is controlled by a transistor
on the instrument cluster electronic circuit board
based upon cluster programming. On models
equipped with airbags the indicator is also controlled
by electronic messages received by the cluster from
the Airbag Control Module (ACM) over the Program-
mable Communications Interface (PCI) data bus. The
seatbelt indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the indicator willalways be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the seatbelt indicator for the following rea-
sons:
²Seatbelt Reminder Function- Each time the
cluster receives a battery current input on the fused
ignition switch output (run-start) circuit, the indica-
tor will be illuminated as a seatbelt reminder for
about six seconds, or until the ignition switch is
turned to the Off position, whichever occurs first.
This reminder function will occur regardless of the
status of the electronic seat belt lamp-on or lamp-off
messages received by the cluster from the ACM.
²Seat Belt Indicator Lamp-On Message-On
models equipped with airbags, following the seatbelt
reminder function, each time the cluster receives a
seat belt indicator lamp-on message from the ACM
indicating the driver side front seat belt is not fas-
tened with the ignition switch in the Start or On
positions, the seatbelt indicator will be illuminated.
The indicator remains illuminated until the cluster
receives a seat belt indicator lamp-off message from
the ACM, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the seatbelt indicator will
be turned on for the duration of the test to confirm
the functionality of the LED and the cluster control
circuitry.
The instrument cluster continually monitors the
status of the ignition switch through the hard wired
fused ignition switch output (run-start) circuit to
determine when to provide the seatbelt reminder
function. On models equipped with airbags, the ACM
continually monitors the status of both front seat belt
switches to determine the proper airbag system
response to a frontal impact of the vehicle. The ACM
then sends the proper seatbelt indicator lamp-on and
lamp-off messages to the instrument cluster based
upon the status of the driver side front seat belt
switch input. For further diagnosis of the seatbelt
indicator or the instrument cluster circuitry that con-
trols the indicator, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the seatbelt
switches, the ACM, the PCI data bus, or the elec-
tronic message inputs to the instrument cluster that
control the seatbelt indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
8J - 28 INSTRUMENT CLUSTERWJ
REAR FOG LAMP INDICATOR (Continued)

switch is turned to the Off position, whichever occurs
first.
²Actuator Test- Each time the cluster is put
through the actuator test, the transmission over-tem-
perature indicator will be turned on for the duration
of the test to confirm the functionality of the bulb
and the cluster control circuitry.
The PCM or TCM continually monitors the trans-
mission temperature sensor to determine the trans-
mission operating condition. The PCM or TCM then
sends the proper trans over-temp indicator lamp-on
or lamp-off messages to the instrument cluster. If the
transmission over-temperature indicator fails to light
during the bulb test, replace the bulb with a known
good unit. If the instrument cluster turns on the
transmission over-temperature indicator due to a
high transmission oil temperature condition, it may
indicate that the transmission or the transmission
cooling system are being overloaded or that they
require service. For further diagnosis of the trans-
mission over-temperature indicator or the instrument
cluster circuitry that controls the indicator, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-
NOSIS AND TESTING). For proper diagnosis of the
transmission temperature sensor, the PCM, the
TCM, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the
transmission over-temperature indicator, a DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
TURN SIGNAL INDICATOR
DESCRIPTION
Two turn signal indicators, one right and one left,
are standard equipment on all instrument clusters.
The turn signal indicators are located near the upper
edge of the instrument cluster, the left one is left of
the tachometer, and the right one is right of the
speedometer. Each turn signal indicator consists of
an International Control and Display Symbol icon for
ªTurn Warningº imprinted on a green lens. Each lens
is located behind a dedicated cutout in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents these icons from
being clearly visible when they are not illuminated.
The icons appear silhouetted against a green field
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by a
replaceable incandescent bulb and bulb holder unit
located on the instrument cluster electronic circuit
board. The turn signal indicator lenses are serviced
as a unit with the instrument cluster lens, hood and
mask unit.
OPERATION
The turn signal indicators give an indication to the
vehicle operator that the turn signal (left or right
indicator flashing) or hazard warning (both left and
right indicators flashing) have been selected and are
operating. These indicators are controlled by two
individual hard wired inputs from the combination
flasher circuitry to the instrument cluster electronic
circuit board. Each turn signal indicator bulb is
grounded on the instrument cluster electronic circuit
board at all times; therefore, these indicators remain
functional regardless of the ignition switch position.
Each indicator bulb will only illuminate when it is
provided with battery current by the combination
flasher in the Junction Block (JB).
The turn signal indicators are connected in parallel
with the other turn signal circuits. This arrangement
allows the turn signal indicators to remain func-
tional, regardless of the condition of the other cir-
cuits in the turn signal and hazard warning systems.
The combination flasher outputs to the instrument
cluster turn signal indicator inputs can be diagnosed
using conventional diagnostic tools and methods. For
more information on the turn signal and hazard
warning system, (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR - OPERATION - TURN
SIGNAL & HAZARD WARNING SYSTEM).
DIAGNOSIS AND TESTING - TURN SIGNAL
INDICATOR
The diagnosis found here addresses an inoperative
turn signal indicator condition. If the problem being
diagnosed is related to inoperative turn signal or
hazard warning lamps, be certain to repair the turn
signal and hazard warning system before attempting
to diagnose or repair the turn signal indicators.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR - DIAGNOSIS AND TESTING - TURN
SIGNAL & HAZARD WARNING SYSTEM). If no
turn signal and hazard warning system problem is
found, the following procedure will help locate an
open in the turn signal indicator circuit. Refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
WJINSTRUMENT CLUSTER 8J - 33
TRANS TEMP INDICATOR (Continued)

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the instrument cluster from the
instrument panel and disconnect the instrument
panel wire harness for the instrument cluster from
the cluster connector receptacle.
(2) Reconnect the battery negative cable. Activate
the hazard warning system by moving the hazard
warning switch button to the On position. Check for
battery voltage at the inoperative (right or left) turn
signal circuit cavity of the instrument panel wire
harness connector for the instrument cluster. There
should be a switching (on and off) battery voltage sig-
nal present. If OK, replace the faulty (right or left)
turn signal indicator bulb. If not OK, repair the open
(right or left) turn signal circuit between the instru-
ment cluster and the combination flasher in the
Junction Block (JB) as required.
VOLTAGE GAUGE
DESCRIPTION
A voltage gauge is standard equipment on all
instrument clusters. The voltage gauge is located in
the upper left corner of the instrument cluster, to the
left of the tachometer. The voltage gauge consists of a
movable gauge needle or pointer controlled by the
instrument cluster circuitry and a fixed 90 degree
scale on the gauge dial face that reads left-to-right
from 9 volts to 19 volts. An International Control and
Display Symbol icon for ªBattery Charging Condi-
tionº is located on the gauge dial face.
The voltage gauge graphics are either white, gray
and orange against a black gauge dial face (base
cluster) or black, gray and red against a taupe gauge
dial face (premium cluster), making them clearly vis-
ible within the instrument cluster in daylight. When
illuminated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-rior lamps turned On, the base cluster white gauge
graphics appear blue-green and the orange graphics
still appear orange, while the premium cluster taupe
gauge dial face appears blue-green with the black
graphics silhouetted against the illuminated back-
ground and the red graphics still appear red. The
gray gauge graphics for both versions of the cluster
are not illuminated. The orange gauge needle in the
base cluster gauge is internally illuminated, while
the black gauge needle in the premium cluster gauge
is not.
Base cluster gauge illumination is provided by
replaceable incandescent bulb and bulb holder units
located on the instrument cluster electronic circuit
board. Premium cluster gauge illumination is pro-
vided by an integral electro-luminescent lamp that is
serviced as a unit with the instrument cluster. The
voltage gauge is serviced as a unit with the instru-
ment cluster.
OPERATION
The voltage gauge gives an indication to the vehi-
cle operator of the electrical system voltage. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
voltage gauge is an air core magnetic unit that
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (run-start) circuit whenever the igni-
tion switch is in the On or Start positions. The clus-
ter is programmed to move the gauge needle back to
the low end of the scale after the ignition switch is
turned to the Off position. The instrument cluster
circuitry controls the gauge needle position and pro-
vides the following features:
²System Voltage Message- Each time the clus-
ter receives a message from the PCM indicating the
system voltage, the cluster moves the gauge needle to
the relative voltage level position on the gauge scale.
²System Voltage Low Message- Each time the
cluster receives a message from the PCM indicating
the system voltage is low (system voltage is about
eleven volts or lower), the gauge needle is moved to
the relative voltage position in the red zone of the
gauge scale and the check gauges indicator is illumi-
nated. The gauge needle remains in the red zone and
the check gauges indicator remains illuminated until
the cluster receives a message from the PCM indicat-
ing there is no low system voltage condition (system
voltage is above about eleven volts, but lower than
about sixteen volts).
²System Voltage High Message- Each time
the cluster receives a message from the PCM indicat-
8J - 34 INSTRUMENT CLUSTERWJ
TURN SIGNAL INDICATOR (Continued)