2002 JEEP LIBERTY warning light

eter/trip odometer switch button that extends
through the lower edge of the cluster lens, just right
of the speedometer. Actuating this switch momen-
tarily with the ignition switch in the On position will
toggle the VFD between the odometer and trip odom-
eter modes. Depressing the switch button for about
two seconds while the VFD is in the trip odometer
mode will reset the trip odometer value to zero. Hold-
ing this switch depressed while turning the ignition
switch from the Off position to the On position will
initiate the EMIC self-diagnostic actuator test. The
VFD will also display the cluster software version
level near the completion of the EMIC self-diagnostic
actuator test. Refer to the appropriate diagnostic
information for additional details on this VFD func-
tion.
The VFD is diagnosed using the EMIC self-diag-
nostic actuator test. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the PCI data bus and
the electronic data bus message inputs to the EMIC
that control some of the VFD functions requires the
use of a DRBIIItscan tool. Refer to the appropriate
diagnostic information. Specific operation details for
the odometer, the trip odometer, and the various
warning message functions of the VFD may be found
elsewhere in this service information.
INDICATORS Indicators are located in various
positions within the EMIC and are all connected to
the EMIC circuit board. The turn signal indicators,
security indicator, washer fluid indicator, and coolant
low indicator (diesel engine only) use hard wired
inputs to the EMIC. The brake indicator is controlled
by PCI data bus messages from the Controller
Antilock Brake (CAB) as well as by hard wired park
brake switch and brake fluid level switch inputs to
the EMIC. The Malfunction Indicator Lamp (MIL) is
normally controlled by PCI data bus messages from
the Powertrain Control Module (PCM); however, if
the EMIC loses PCI data bus communication, the
EMIC circuitry will automatically turn the MIL on
until PCI data bus communication is restored. The
EMIC uses PCI data bus messages from the Body
Control Module (BCM), the PCM, the Airbag Control
Module (ACM), and the CAB to control all of the
remaining indicators.
The various indicators are controlled by different
strategies; some receive fused ignition switch output
from the EMIC circuitry and have a switched ground,
others are grounded through the EMIC circuitry and
have a switched battery feed, while still others are
completely controlled by the EMIC microprocessor
based upon various hard wired and electronic mes-
sage inputs. Some indicators are illuminated at a
fixed intensity, while the illumination intensity ofothers is synchronized with that of the EMIC general
illumination lamps.
In addition, certain indicators in this instrument
cluster are automatically configured or self-config-
ured. This feature allows the configurable indicators
to be enabled by the EMIC circuitry for compatibility
with certain optional equipment. The ABS indicator,
airbag indicator, SKIS indicator are automatically
configured by PCI data bus messages received by the
EMIC from the CAB, ACM, or Sentry Key Immobi-
lizer Module (SKIM) after the EMIC is installed in
the vehicle. Once these configuration settings are
learned by the EMIC, the DRBIIItscan tool must be
used to remove these settings from the EMIC non-
volatile memory. The self-configured indicators
remain latent in each EMIC at all times and will be
activated only when the EMIC receives the appropri-
ate PCI message inputs for the optional system or
equipment.
The hard wired indicators are diagnosed using con-
ventional diagnostic methods. The EMIC and PCI
bus message controlled indicators are diagnosed
using the EMIC self-diagnostic actuator test. (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). Proper testing of the
PCI data bus and the electronic data bus message
inputs to the EMIC that control each indicator
require the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information. Specific details of
the operation for each indicator may be found else-
where in this service information.
CLUSTER ILLUMINATION The EMIC has several
illumination lamps that are illuminated when the
exterior lighting is turned on with the headlamp
(multi-function) switch. The illumination intensity of
these lamps is adjusted by a 12-volt Pulse Width
Modulated (PWM) output of the EMIC when the
interior lighting control ring on the left control stalk
of the multi-function switch is rotated (down to dim,
up to brighten) to one of six available minor detent
positions. The BCM provides electronic dimming
level messages based upon internal programming
and inputs it receives from the control knob and con-
trol ring on the left (lighting) control stalk of the
multi-function switch on the steering column, then
provides a control output to energize or de-energize
the park lamp relay as appropriate. The energized
park lamp relay provides battery current to the
EMIC on the hard wired fused park lamp relay out-
put circuit, and the BCM provides the electronic dim-
ming level message to the EMIC over the PCI data
bus. The EMIC electronic circuitry provides the
proper PWM output to the cluster illumination lamps
and the VFD on the EMIC circuit board, then pro-
vides a synchronized PWM output on the hard wired
8J - 6 INSTRUMENT CLUSTERKJ
INSTRUMENT CLUSTER (Continued)

fused panel lamps dimmer switch signal circuit. The
cluster illumination lamps are grounded at all times.
In addition, the control ring on the left (lighting)
control stalk of the multi-function switch has a
Parade Mode position to provide a parade mode. The
BCM monitors the request for this mode from the
multi-function switch, then sends an electronic dim-
ming level message to the EMIC over the PCI data
bus to illuminate all VFDs in the vehicle at full
intensity for easier visibility when driving in daylight
with the exterior lighting turned On.
The hard wired cluster illumination lamp circuits
may be diagnosed using conventional diagnostic
methods. However, proper testing of the PWM output
of the EMIC and the electronic dimming level mes-
sages sent by the BCM over the PCI data bus
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
CHIME WARNING SERVICE The EMIC is pro-
grammed to provide chime service when certain indi-
cators are illuminated. When the programmed
conditions are met, the EMIC generates an electronic
chime tone through its integral chime tone generator.
In addition, the EMIC is programmed to provide
chime service for other electronic modules in the
vehicle when it receives the proper electronic chime
request messages over the PCI data bus. Upon
receiving the proper chime request message, the
EMIC activates the integral chime tone generator to
provide the audible chime tone to the vehicle opera-
tor. (Refer to 8 - ELECTRICAL/CHIME/BUZZER -
OPERATION). Proper testing of the EMIC and the
PCI data bus chime request message functions
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER
If all of the instrument cluster gauges and/or indi-
cators are inoperative, refer to PRELIMINARY
DIAGNOSIS . If an individual gauge or Programma-
ble Communications Interface (PCI) data bus mes-
sage-controlled indicator is inoperative, refer to
ACTUATOR TEST . If an individual hard wired indi-
cator is inoperative, refer to the diagnosis and testing
information for that specific indicator. If the instru-
ment cluster chime service is inoperative, refer to
CHIME SERVICE DIAGNOSIS . If the instrument
cluster illumination lighting is inoperative, refer to
CLUSTER ILLUMINATION DIAGNOSIS . Refer to
the appropriate wiring information. The wiring infor-
mation 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 con-
nectors, splices and grounds.NOTE: Certain indicators in this instrument cluster
are automatically configured. This feature allows
those indicators to be activated for compatibility
with certain optional equipment. If the problem
being diagnosed involves illumination of the ABS
indicator, the airbag indicator, or the SKIS indicator
when the vehicle does not have this equipment, a
DRBIIITscan tool must be used to disable the erro-
neous indicator(s). Refer to the appropriate diag-
nostic information.
PRELIMINARY DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
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) Check the fused B(+) fuse (Fuse 34 - 15
ampere) in the Junction Block (JB). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
(Fuse 34 - 15 ampere) in the JB. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(3) Disconnect and isolate the battery negative
cable. Remove the instrument cluster. Reconnect the
battery negative cable. Check for battery voltage at
the fused B(+) circuit cavity of the instrument panel
wire harness connector for the instrument cluster. If
OK, go to Step 4. If not OK, repair the open fused
B(+) circuit between the instrument cluster and the
JB as required.
(4) Check the fused ignition switch output (run-
start) fuse (Fuse 13 - 10 ampere) in the JB. If OK, go
to Step 5. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run-start) fuse (Fuse 13 - 10 ampere) in the
JB. If OK, go to Step 6. If not OK, repair the open
KJINSTRUMENT CLUSTER 8J - 7
INSTRUMENT CLUSTER (Continued)

(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) From the back of the instrument cluster, install
and tighten the six screws that secure the rear cover
and the lens, hood, and mask unit to the cluster
housing. Tighten the screws to 1 N´m (10 in. lbs.).
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) 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, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
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) Position the instrument cluster to the instru-
ment panel.
(2) Reconnect the instrument panel wire harness
connector for the cluster to the cluster connector
receptacle.
(3) Position the instrument cluster into the instru-
ment panel.
(4) Install and tighten the four screws that secure
the instrument cluster to the instrument panel (Fig.
3). Tighten the screws to 2 N´m (17 in. lbs.).
(5) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(6) Reconnect the battery negative cable.NOTE: Some of the indicators in this instrument
cluster are self configured or automatically config-
ured when the cluster is connected to the vehicle
electrical system. This feature allows those indica-
tors to be enabled for compatibility with certain
optional equipment. However, if an instrument clus-
ter was previously connected to another vehicle
with different equipment options than the current
vehicle, some of the automatically configured indi-
cator settings may have to be disabled using a
DRBIIITscan tool. Refer to the appropriate diagnos-
tic information.
ABS INDICATOR
DESCRIPTION
An Antilock Brake System (ABS) indicator is stan-
dard equipment on all instrument clusters. However,
the instrument cluster is programmed to automati-
cally enable this indicator only on vehicles equipped
with the optional antilock brake system. The ABS
indicator is located above the engine temperature
gauge and to the right of the speedometer in the
instrument cluster. The ABS indicator consists of a
stencil-like cutout of the International Control and
Display Symbol icon for ªFailure of Anti-lock Braking
Systemº in the opaque layer of the instrument clus-
ter overlay. The dark outer layer of the overlay pre-
vents the indicator from being clearly visible when it
is not illuminated. An amber Light Emitting Diode
(LED) behind the cutout in the opaque layer of the
overlay causes the icon to appear in amber through
the translucent outer layer of the overlay when it is
illuminated from behind by the LED, which is sol-
dered onto the instrument cluster electronic circuit
board. The ABS indicator is serviced as a unit with
the instrument cluster.
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 Antilock Brake (CAB)
over the Programmable Communications Interface
(PCI) data bus. The ABS indicator Light Emitting
Diode (LED) 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 LED will always be off when the ignition switch
is in any position except On or Start. The LED only
KJINSTRUMENT CLUSTER 8J - 11
INSTRUMENT CLUSTER (Continued)

remains illuminated until the cluster receives a sin-
gle lamp-off message from the ACM.
²Actuator Test- Each time the cluster is put
through the actuator test, the airbag indicator will be
turned on, then off again during the bulb check por-
tion of the test to confirm the functionality of the
LED and the cluster control circuitry. The actuator
test illumination of the airbag indicator is a function
of the instrument cluster.
The ACM continually monitors the airbag system
circuits and sensors to decide whether the system is
in good operating condition. The ACM then sends the
proper lamp-on or lamp-off messages to the instru-
ment cluster. If the ACM sends a lamp-on message
after the bulb test, it indicates that the ACM has
detected a system malfunction and/or that the air-
bags and driver seat belt tensioner may not deploy
when required, or may deploy when not required.
The ACM will store a Diagnostic Trouble Code (DTC)
for any malfunction it detects. Each time the airbag
indicator fails to illuminate due to an open or short
in the cluster airbag indicator circuit, the cluster
sends a message notifying the ACM of the condition,
then the instrument cluster and the ACM will each
store a DTC. For proper diagnosis of the airbag sys-
tem, the ACM, the PCI data bus, or the message
inputs to the instrument cluster that control the air-
bag indicator, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
BRAKE/PARK BRAKE
INDICATOR
DESCRIPTION
A brake indicator is standard equipment on all
instrument clusters. The brake indicator is located
near the lower edge of the tachometer dial face in the
instrument cluster. The brake indicator consists of
stencil-like cutouts of the word ªBRAKEº and the
International Control and Display Symbol icon for
ªBrake Failureº in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. A red Light Emitting
Diode (LED) behind the cutout in the opaque layer of
the overlay causes the ªBRAKEº text and the icon to
appear in red through the translucent outer layer of
the overlay when the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The brake
indicator is serviced as a unit with the instrument
cluster.
OPERATION
The brake indicator gives an indication to the vehi-
cle operator when the parking brake is applied, when
there are certain brake hydraulic system malfunc-
tions as indicated by a low brake hydraulic fluid level
condition, or when the brake fluid level switch is dis-
connected. On models equipped with an optional
Antilock Brake System (ABS), the brake indicator
can also give an indication when certain faults are
detected in the 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
Antilock Brake (CAB) over the Programmable Com-
munications Interface (PCI) data bus (ABS only), and
hard wired inputs from the park brake switch and
the brake fluid level 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) cir-
cuit. Therefore, the LED will always be off when the
ignition switch is in any position except On or Start.
The LED only illuminates 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 reasons:
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 Lamp-On Message- Each time the
cluster receives a lamp-on message from the CAB,
the brake indicator will be illuminated. The indicator
remains illuminated until the cluster receives a
lamp-off message from the CAB, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Park Brake Switch Input- Each time the
cluster detects ground on the park brake switch
sense circuit (park brake switch closed = park brake
applied or not fully released) the brake indicator 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.
²Brake Fluid Level Switch Input- Each time
the cluster detects ground on the red brake warning
indicator driver circuit (brake fluid level switch
closed = brake hydraulic system fluid level low) the
brake indicator is illuminated solid. The indicator
remains illuminated until the status of the red brake
warning indicator driver input to the cluster is off
(brake fluid level switch off = brake hydraulic system
KJINSTRUMENT CLUSTER 8J - 13
AIRBAG INDICATOR (Continued)

OPERATION
The cruise indicator gives an indication to the vehi-
cle operator when the speed control system is turned
On, regardless of whether the speed control is
engaged. This indicator is controlled by a transistor
on the instrument cluster electronic circuit board
based upon the cluster programming and electronic
messages received by the cluster from the Powertrain
Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The cruise
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 cur-
rent input on the fused ignition switch output (run-
start) circuit. Therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
cruise indicator for the following reasons:
²Cruise Lamp-On Message- Each time the
cluster receives a cruise lamp-on message from the
PCM indicating the speed control system has been
turned On, the cruise indicator is illuminated. The
indicator remains illuminated until the cluster
receives a cruise lamp-off message from the PCM 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 cruise indicator will be
turned on, then off again during the bulb check por-
tion of the test in order to confirm the functionality
of the LED and the cluster control circuitry.
The PCM continually monitors the speed control
switches to determine the proper outputs to the
speed control servo. The PCM then sends the proper
cruise indicator lamp-on and lamp-off messages to
the instrument cluster. For further diagnosis of the
cruise 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 speed control
system, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the cruise indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
DOOR AJAR INDICATOR
DESCRIPTION
A door ajar indicator is standard equipment on all
instrument clusters. The door ajar indicator consists
of the word ªdoorº, which appears in place of the
odometer/trip odometer information in the Vacuum-Fluorescent Display (VFD) of the instrument cluster.
The VFD is part of the cluster electronic circuit
board, and is visible through a cutout located near
the lower edge of the speedometer dial face in the
instrument cluster. The dark outer layer of the over-
lay prevents the VFD from being clearly visible when
it is not illuminated. The word ªdoorº appears in the
same blue-green color and at the same lighting level
as the odometer/trip odometer information through
the translucent outer layer of the overlay when it is
illuminated by the instrument cluster electronic cir-
cuit board. The door ajar indicator is serviced as a
unit with the instrument cluster.
OPERATION
The door ajar indicator gives an indication to the
vehicle operator that one or more of the passenger
compartment doors may be open or not completely
latched. This indicator is controlled by the instru-
ment cluster electronic circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the Body Control Module (BCM)
over the Programmable Communications Interface
(PCI) data bus. The door ajar indicator function of
the Vacuum Fluorescent Display (VFD) 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 cur-
rent input on the fused ignition switch output (run-
start) circuit. Therefore, the VFD door ajar indication
will always be off when the ignition switch is in any
position except On or Start. The instrument cluster
will turn on the door ajar indicator for the following
reasons:
²Door Ajar Lamp-On Message- Each time the
cluster receives a door ajar lamp-on message from
the BCM indicating that a door is open or not com-
pletely latched, the door ajar indicator will be illumi-
nated. If the vehicle is not moving when the door
ajar lamp-on message is received, the VFD will
repeatedly and sequentially cycle its indication in
two second intervals with the odometer/trip odometer
information, the door ajar warning, and any other
active warnings including: gate ajar, glass ajar, and
low washer fluid. If the vehicle is moving, or once the
cluster of a non-moving vehicle receives an electronic
vehicle speed message from the Powertrain Control
Module (PCM) indicating a speed greater than zero,
the warning sequence will consist of three complete
display cycles, then revert to only the odometer/trip
odometer display until the door ajar switch is cycled.
The door ajar indicator will also be extinguished
when the cluster receives a door ajar lamp-off mes-
sage from the BCM, or if the ignition switch is
turned to the Off position, whichever occurs first.
KJINSTRUMENT CLUSTER 8J - 17
CRUISE INDICATOR (Continued)

The BCM continually monitors the door ajar
switches that are integral to each door latch to deter-
mine the status of the doors. The BCM then sends
the proper door ajar lamp-on and lamp-off messages
to the instrument cluster. For further diagnosis of
the door ajar indicator or the instrument cluster cir-
cuitry that controls the indicator, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). For proper diagnosis of the door
ajar switches and circuits, the BCM, the PCI data
bus, or the electronic message inputs to the instru-
ment cluster that control the door ajar indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
ENGINE TEMPERATURE
GAUGE
DESCRIPTION
An engine coolant temperature gauge is standard
equipment on all instrument clusters. The engine
coolant temperature gauge is located in the right
lower corner of the instrument cluster, to the right of
the speedometer. The engine coolant temperature
gauge consists of a movable gauge needle or pointer
controlled by the instrument cluster circuitry and a
fixed 90 degree scale on the cluster overlay that
reads left-to-right from ªCº (or Cold) to ªHº (or Hot)
for all engines. An International Control and Display
Symbol icon for ªEngine Coolant Temperatureº is
located on the cluster overlay, in the center of the
gauge directly above the hub of the gauge needle.
The engine coolant temperature gauge graphics are
dark blue and black against a beige field, except for a
single light blue graduation at the far left (Cold) end
of the gauge scale and a single red graduation at the
far right (Hot) end of the gauge scale, making them
clearly visible within the instrument cluster in day-
light. When illuminated from behind by the panel
lamps dimmer controlled cluster illumination lighting
with the exterior lamps turned On, the blue graphics
appear blue and the red graphics appear red. The
orange gauge needle is internally illuminated. Gauge
illumination is provided by replaceable incandescent
bulb and bulb holder units located on the instrument
cluster electronic circuit board. The engine coolant
temperature gauge is serviced as a unit with the
instrument cluster.
OPERATION
The engine coolant temperature gauge gives an
indication to the vehicle operator of the engine cool-
ant temperature. This gauge is controlled by the
instrument cluster circuit board based upon cluster
programming and electronic messages received bythe cluster from the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The engine coolant temper-
ature gauge is an air core magnetic unit that receives
battery current on the instrument cluster electronic
circuit board through the fused ignition switch out-
put (run-start) circuit whenever the ignition switch is
in the On or Start positions. The cluster is pro-
grammed 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 Temperature Normal Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is within
the normal operating range [up to about 124É C (255É
F) for gasoline engines, or about 110É C (230É F) for
diesel engines], the gauge needle is moved to the rel-
ative temperature position of the gauge scale.
²Engine Temperature High Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is high
[above about 127É C (260É F) for gasoline engines, or
112É C (233É F) for diesel engines], the gauge needle
is moved into the center of the red warning zone on
the gauge scale.
²Engine Temperature Critical Message-
Each time the cluster receives a message from the
PCM indicating the engine coolant temperature is
critical [above about 132É C (269É F) for gasoline
engines, or 115É C (239É F) for diesel engines], the
gauge needle is moved to the high end of the red
warning zone on the gauge scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to the gauge calibration points on the gauge
scale in sequence in order to confirm the functional-
ity of the gauge and the cluster control circuitry.
The PCM continually monitors the engine coolant
temperature sensor to determine the engine operat-
ing temperature. The PCM then sends the proper
engine coolant temperature messages to the instru-
ment cluster. For further diagnosis of the engine cool-
ant temperature gauge or the instrument cluster
circuitry that controls the gauge, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster moves the
engine coolant temperature gauge needle to indicate
a high or critical engine temperature, it may indicate
that the engine or the engine cooling system requires
service. For proper diagnosis of the engine coolant
temperature sensor, the PCM, the PCI data bus, or
the electronic message inputs to the instrument clus-
ter that control the engine coolant temperature
8J - 18 INSTRUMENT CLUSTERKJ
DOOR AJAR INDICATOR (Continued)

instrument cluster will turn on the gate ajar indica-
tor for the following reasons:
²Gate Ajar Lamp-On Message- Each time the
cluster receives a gate ajar lamp-on message from
the BCM indicating that the rear tailgate is open or
not completely latched, the gate ajar indicator will be
illuminated. If the vehicle is not moving when the
gate ajar lamp-on message is received, the VFD will
repeatedly and sequentially cycle its indication in
two second intervals with the odometer/trip odometer
information, the gate ajar warning, and any other
active warnings including: door ajar, glass ajar, and
low washer fluid. If the vehicle is moving, or once the
cluster of a non-moving vehicle receives an electronic
vehicle speed message from the Powertrain Control
Module (PCM) indicating a speed greater than zero,
the warning sequence will consist of three complete
display cycles, then revert to only the odometer/trip
odometer display until the tailgate ajar switch is
cycled. The gate ajar indicator will also be extin-
guished when the cluster receives a gate ajar lamp-
off message from the BCM, or if the ignition switch is
turned to the Off position, whichever occurs first.
The BCM continually monitors the tailgate ajar
switch that is integral to the tailgate latch to deter-
mine the status of the rear tailgate. The BCM then
sends the proper gate ajar lamp-on and lamp-off mes-
sages to the instrument cluster. For further diagnosis
of the gate ajar indicator or the instrument cluster
circuitry that controls the indicator, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the tail-
gate ajar switch and circuit, the BCM, the PCI data
bus, or the electronic message inputs to the instru-
ment cluster that control the gate ajar indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
GLASS AJAR INDICATOR
DESCRIPTION
A glass ajar indicator is standard equipment on all
instrument clusters. The glass ajar indicator consists
of the word ªglassº, which appears in place of the
odometer/trip odometer information in the Vacuum-
Fluorescent Display (VFD) of the instrument cluster.
The VFD is part of the cluster electronic circuit
board, and is visible through a cutout located near
the lower edge of the speedometer dial face in the
instrument cluster. The dark outer layer of the over-
lay prevents the VFD from being clearly visible when
it is not illuminated. The word ªglassº appears in the
same blue-green color and at the same lighting level
as the odometer/trip odometer information through
the translucent outer layer of the overlay when it isilluminated by the instrument cluster electronic cir-
cuit board. The glass ajar indicator is serviced as a
unit with the instrument cluster.
OPERATION
The glass ajar indicator gives an indication to the
vehicle operator that the rear flip-up glass may be
open or not completely latched. This indicator is con-
trolled by the instrument cluster electronic circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Body Control Module (BCM) over the Programmable
Communications Interface (PCI) data bus. The glass
ajar indicator function of the Vacuum Fluorescent
Display (VFD) 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 VFD glass ajar indicator will always be off when
the ignition switch is in any position except On or
Start. The instrument cluster will turn on the glass
ajar indicator for the following reasons:
²Glass Ajar Lamp-On Message- Each time the
cluster receives a glass ajar lamp-on message from
the BCM indicating that the rear flip-up glass is
open or not completely latched, the glass ajar indica-
tor will be illuminated. If the vehicle is not moving
when the glass ajar lamp-on message is received, the
VFD will repeatedly and sequentially cycle its indica-
tion in two second intervals with the odometer/trip
odometer information, the glass ajar warning, and
any other active warnings including: door ajar, gate
ajar, and low washer fluid. If the vehicle is moving,
or once the cluster of a non-moving vehicle receives
an electronic vehicle speed message from the Power-
train Control Module (PCM) indicating a speed
greater than zero, the warning sequence will consist
of three complete display cycles, then revert to only
the odometer/trip odometer display until the glass
ajar switch is cycled. The glass ajar indicator will
also be extinguished when the cluster receives a
glass ajar lamp-off message from the BCM, or if the
ignition switch is turned to the Off position, which-
ever occurs first.
The BCM continually monitors the glass ajar
switch that is integral to the flip-up glass latch to
determine the status of the rear flip-up glass. The
BCM then sends the proper glass ajar lamp-on and
lamp-off messages to the instrument cluster. For fur-
ther diagnosis of the glass ajar indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the glass ajar switch and circuit,
the BCM, the PCI data bus, or the electronic mes-
KJINSTRUMENT CLUSTER 8J - 21
GATE AJAR INDICATOR (Continued)

dition. The PCM then sends the proper malfunction
indicator lamp-on or lamp-off messages to the instru-
ment cluster. For further diagnosis of the MIL or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). If the instru-
ment cluster turns on the MIL after the bulb test, it
may indicate that a malfunction has occurred and
that the fuel and emissions system may require ser-
vice. For proper diagnosis of the fuel and emissions
systems, the PCM, the PCI data bus, or the elec-
tronic message inputs to the instrument cluster that
control the MIL, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters. The odometer
and trip odometer information are displayed in a
common electronic, blue-green Vacuum Fluorescent
Display (VFD), which is located in the lower edge of
the speedometer dial face in the instrument cluster
and, when illuminated, is visible through a small
window cutout in the cluster overlay. However, the
odometer and trip odometer information are not dis-
played simultaneously. The trip odometer reset
switch on the instrument cluster electronic circuit
board toggles the display between odometer and trip
odometer modes by depressing the odometer/trip
odometer switch knob that extends through the lower
edge of the cluster lens, just right of the odometer
VFD. Both the odometer and trip odometer informa-
tion is stored in the instrument cluster memory.
All odometer and trip odometer distance informa-
tion is stored in the instrument cluster. This distance
information can be increased when the proper inputs
are provided to the instrument cluster, but the dis-
tance information cannot be decreased. The odometer
can display values up to 864,004 kilometers (536,870
miles). The odometer will not roll over, but will latch
at the maximum value. The trip odometer can dis-
play values up to 9999.9 kilometers (9999.9 miles)
before it rolls over to zero. The odometer display does
not have a decimal point and will not show values
less than a full unit (kilometer or mile), the trip
odometer display does have a decimal point and will
show tenths of a unit (kilometer or mile). When the
trip odometer is active, the word ªTRIPº will also
illuminate near the bottom of the VFD. The unit of
measure for the odometer and trip odometer display
is not shown in the VFD. If the instrument cluster
has a kilometers-per-hour primary speedometer
scale, the odometer/trip odometer registers kilome-ters; and if the cluster features a miles-per-hour pri-
mary speedometer scale, the odometer/trip odometer
registers miles. In this instrument cluster, the odom-
eter/trip odometer VFD is also used to display certain
warning messages and diagnostic information.
The odometer/trip odometer has a ªRental Carº
mode, which will illuminate the odometer informa-
tion in the VFD whenever the driver side front door
is opened with the ignition switch in the Off or
Accessory positions. During daylight hours (exterior
lamps Off) the VFD is illuminated at full brightness
for clear visibility. At night (exterior lamps are On)
the instrument cluster converts an electronic dim-
ming level message received from the Body Control
Module (BCM) over the Programmable Communica-
tions Interface (PCI) data bus to a digital dimming
level signal for controlling the lighting level of the
VFD. However, a ªParadeº mode position of the panel
lamps dimmer control ring on the multi-function
switch left control stalk allows the VFD to be illumi-
nated at full brightness if the exterior lamps are
turned On during daylight hours.
The VFD, the trip odometer switch, and the trip
odometer switch button are serviced as a unit with
the instrument cluster.
OPERATION
The odometer and trip odometer give an indication
to the vehicle operator of the distance the vehicle has
traveled. This gauge is controlled by the instrument
cluster electronic circuitry based upon cluster pro-
gramming and electronic messages received by the
cluster from the Powertrain Control Module (PCM)
over the Programmable Communications Interface
(PCI) data bus. The odometer and trip odometer
information is displayed by the instrument cluster
Vacuum Fluorescent Display (VFD). The VFD will
display the odometer information whenever the
driver side front door is opened with the ignition
switch in the Off or Accessory positions, and will dis-
play the last previously selected odometer or trip
odometer information when the ignition switch is in
the On or Start positions. The instrument cluster cir-
cuitry controls the VFD and provides the following
features:
²Odometer/Trip Odometer Display Toggling-
Actuating the trip odometer reset switch momen-
tarily with the VFD illuminated will toggle the dis-
play between the odometer and trip odometer
information. Each time the VFD is illuminated with
the ignition switch in the On or Start positions, the
display will automatically return to the last mode
previously selected (odometer or trip odometer).
²Trip Odometer Reset- When the trip odome-
ter reset switch is pressed and held for longer than
about two seconds with the ignitions switch in the
KJINSTRUMENT CLUSTER 8J - 25
MALFUNCTION INDICATOR LAMP (MIL) (Continued)