Failure JEEP GRAND CHEROKEE 2003 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)

Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The tachome-
ter 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 ignition switch is in the
On or Start positions. The cluster 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 provides the following
features:
²Engine Speed Message- Each time the cluster
receives an engine speed message from the PCM it
will calculate the correct engine speed reading and
position the gauge needle at that speed position on
the gauge scale. The cluster will receive a new
engine speed message and reposition the gauge
pointer accordingly about every 86 milliseconds. The
gauge needle will continue to be positioned at the
actual engine speed position on the gauge scale until
the ignition switch is turned to the Off position.
²Communication Error- If the cluster fails to
receive an engine speed message, it will hold the
gauge needle at the last indication for about six sec-
onds, or until the ignition switch is turned to the Off
position, whichever occurs first. If a new engine
speed message is not received after about six sec-
onds, the gauge needle will return to the far left
(low) end of the scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept across the entire gauge scale and back in order
to confirm the functionality of the gauge and the
cluster control circuitry.
The PCM continually monitors the crankshaft posi-
tion sensor to determine the engine speed, then
sends the proper engine speed messages to the
instrument cluster. For further diagnosis of the
tachometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the crankshaft position
sensor, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the tachometer, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
TRANS TEMP INDICATOR
DESCRIPTION
A transmission over-temperature indicator is stan-
dard equipment on all gasoline engine instrument
clusters. The transmission over-temperature indica-
tor is located near the lower right corner of theinstrument cluster, to the right of the speedometer.
The transmission over-temperature indicator consists
of the words ªTRANS OVER TEMPº 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 indi-
cator from being clearly visible when it is not illumi-
nated. The words ªTRANS OVER TEMPº appear
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
transmission over-temperature indicator lens is ser-
viced as a unit with the instrument cluster lens, hood
and mask unit.
OPERATION
The transmission over-temperature indicator gives
an indication to the vehicle operator when the trans-
mission fluid temperature is excessive, which may
lead to accelerated transmission component wear or
failure. This indicator is controlled by a transistor on
the instrument cluster electronic circuit board based
upon cluster programming and electronic messages
received by the cluster over the Programmable Com-
munications Interface (PCI) data bus. These mes-
sages are sent by the Powertrain Control Module
(PCM) or by the Transmission Control Module
(TCM), depending on the model of the automatic
transmission. The transmission over-temperature
indicator bulb is completely controlled by the instru-
ment 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 indicator will always be off when the ignition
switch is in any position except On or Start. The bulb
only illuminates when it is provided a path to ground
by the instrument cluster transistor. The instrument
cluster will turn on the transmission over-tempera-
ture indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the transmission over-tem-
perature indicator is illuminated for about three sec-
onds as a bulb test.
²Trans Over-Temp Indicator Lamp-On Mes-
sage- Each time the cluster receives a trans over-
temp indicator lamp-on message from the PCM or
TCM indicating that the transmission fluid tempera-
ture is 135É C (275É F) or higher, the transmission
over-temperature indicator will be illuminated. The
indicator remains illuminated until the cluster
receives a trans over-temp indicator lamp-off mes-
sage from the PCM or TCM, or until the ignition
8J - 32 INSTRUMENT CLUSTERWJ
TACHOMETER (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)

ergize the combination flasher in response to mes-
sage inputs received over the Programmable
Communications Interface (PCI) data bus network.
The BCM can energize the combination flasher when
the VTSS is requested.
Vehicles equipped with the optional Electronic
Vehicle Information Center (EVIC) use turn signal
status messages received from the Electro-Mechani-
cal Instrument Cluster (EMIC) and distance mes-
sages received from the Powertrain Control Module
(PCM) over the PCI data bus to determine when the
Turn Signal On warning should be activated. The
EMIC receives hard wired inputs from the combina-
tion flasher to operate the turn signal indicators,
then sends the proper turn signal status message to
the EVIC. If a turn signal is left on for more than
about 1.6 kilometers (1 mile) of driving distance, the
EVIC will display a visual ªTurn Signal Onº message
and will send a request to the BCM over the PCI
data bus to notify the vehicle operator.
During both the turn signal and the hazard warn-
ing operation, if the exterior lamps are turned Off,
the front park/turn signal lamps and the front side
marker lamps will flash in unison. If the exterior
lamps are turned On, the front park/turn signal
lamps and the front side marker lamps will flash
alternately. Refer to the owner's manual.
DIAGNOSIS AND TESTING - TURN SIGNAL &
HAZARD WARNING SYSTEMS
When diagnosing the turn signal and hazard warn-
ing circuits, remember that high generator output
can burn out bulbs rapidly and repeatedly. If this is a
concern on the vehicle being diagnosed, test the
charging system as required.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Turn the ignition switch to the On position.
Actuate the turn signal switch or the hazard warning
switch. Observe the turn signal indicator lamp(s) in
the instrument cluster. If the flash rate is very high,
check for a turn signal bulb that is not lit or is verydimly lit. Repair the circuits to that lamp or replace
the faulty bulb, as required. If the turn signal indi-
cator(s) fail to light, go to Step 2.
(2) Turn the ignition switch to the Off position.
Check the ignition run fuse and the flasher fuse in
the Junction Block (JB). If OK, go to Step 3. If not
OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).
(3) Check for battery voltage at the flasher fuse in
the JB. If OK, go to Step 4. If not OK, repair the
open fused B(+) circuit between the JB and the
Power Distribution Center (PDC).
(4) Turn the ignition switch to the On position.
Check for battery voltage at the ignition run fuse in
the JB. If OK, go to Step 5. If not OK, repair the
open fused ignition switch output (run) circuit
between the JB and the ignition switch.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the combination flasher from the JB and
replace it with a known good unit. Reconnect the bat-
tery negative cable. Test the operation of the turn
signal and hazard warning systems. If OK, discard
the faulty combination flasher. If not OK, remove the
test flasher and go to Step 6.
(6) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) circuit cavity in the JB for the combina-
tion flasher. If OK, go to Step 7. If not OK, repair the
open fused ignition switch output (run) circuit
between the combination flasher and the ignition run
fuse in the JB.
(7) Turn the ignition switch to the Off position.
Check for battery voltage at the B(+) circuit of the JB
for the combination flasher. If OK, go to Step 8. If
not OK, repair the open B(+) circuit between the
combination flasher and the flasher fuse in the JB.
(8) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the turn signal and hazard warning
switches from the multi-function switch connector.
Check for continuity between the ground circuit of
the instrument panel wire harness connector for the
left multi-function switch and a good ground. There
should be continuity. If OK, go to Step 9. If not OK,
repair the open ground circuit.
(9) Check for continuity between the hazard switch
sense circuit of the instrument panel wire harness
connector for the multi-function switch and a good
ground. There should be no continuity. If OK, go to
Step 10. If not OK, repair the shorted hazard switch
sense circuit between the multi-function switch and
the combination flasher.
(10) Check for continuity between the hazard
switch sense circuit of the JB for the combination
flasher and the instrument panel wire harness con-
WJLAMPS/LIGHTING - EXTERIOR 8L - 3
LAMPS/LIGHTING - EXTERIOR (Continued)