2002 JEEP LIBERTY warning light

TRANSMISSION
TABLE OF CONTENTS
page page
TRANS COOLER
DESCRIPTION.........................30STANDARD PROCEDURE - FLUSHING
COOLERS AND TUBES.................30
TRANS COOLER
DESCRIPTION
An internal high capacity/high efficiency cooler is
used on all vehicles, these coolers are an oil-to-cool-
ant type, which consists of plates mounted in the
radiator outlet tank.Because the internal oil cooler is
so efficient, no auxiliary oil cooler is offered. The
cooler is not serviceable separately from the radiator.
STANDARD PROCEDURE - FLUSHING
COOLERS AND TUBES
When a transmission failure has contaminated the
fluid, the oil cooler(s) must be flushed. The torque
converter must also be replaced. This will insure that
metal particles or sludged oil are not later trans-
ferred back into the reconditioned (or replaced) trans-
mission.
The only recommended procedure for flushing cool-
ers and lines is to use Tool 6906-B Cooler Flusher.
WARNING: WEAR PROTECTIVE EYEWEAR THAT
MEETS THE REQUIREMENTS OF OSHA AND ANSI
Z87.1±1968. WEAR STANDARD INDUSTRIAL RUB-
BER GLOVES. KEEP LIGHTED CIGARETTES,
SPARKS, FLAMES, AND OTHER IGNITION
SOURCES AWAY FROM THE AREA TO PREVENT
THE IGNITION OF COMBUSTIBLE LIQUIDS AND
GASES. KEEP A CLASS (B) FIRE EXTINGUISHER IN
THE AREA WHERE THE FLUSHER WILL BE USED.
KEEP THE AREA WELL VENTILATED.DO NOT LET
FLUSHING SOLVENT COME IN CONTACT WITH
YOUR EYES OR SKIN: IF EYE CONTAMINATION
OCCURS, FLUSH EYES WITH WATER FOR 15 TO 20
SECONDS. REMOVE CONTAMINATED CLOTHING
AND WASH AFFECTED SKIN WITH SOAP AND
WATER. SEEK MEDICAL ATTENTION.
(1) Remove cover plate filler plug on Tool 6906-B.
Fill reservoir 1/2 to 3/4 full of fresh flushing solution.
Flushing solvents are petroleum based solutions gen-
erally used to clean automatic transmission compo-
nents.DO NOTuse solvents containing acids, water,
gasoline, or any other corrosive liquids.(2) Reinstall filler plug on Tool 6906-B.
(3) Verify pump power switch is turned OFF. Con-
nect red alligator clip to positive (+) battery post.
Connect black (-) alligator clip to a good ground.
(4) Disconnect the cooler lines at the transmission.
NOTE: When flushing transmission cooler and
lines, ALWAYS reverse flush.
NOTE: The converter drainback valve must be
removed and an appropriate replacement hose
installed to bridge the space between the transmis-
sion cooler line and the cooler fitting. Failure to
remove the drainback valve will prevent reverse
flushing the system. A suitable replacement hose
can be found in the adapter kit supplied with the
flushing tool.
(5) Connect the BLUE pressure line to the OUT-
LET (From) cooler line.
(6) Connect the CLEAR return line to the INLET
(To) cooler line
(7) Turn pump ON for two to three minutes to
flush cooler(s) and lines.
(8) Turn pump OFF.
(9) Disconnect CLEAR suction line from reservoir
at cover plate. Disconnect CLEAR return line at
cover plate, and place it in a drain pan.
(10) Turn pump ON for 30 seconds to purge flush-
ing solution from cooler and lines. Turn pump OFF.
(11) Place CLEAR suction line into a one quart
container of MopartATF +4, type 9602, Automatic
Transmission Fluid.
(12) Turn pump ON until all transmission fluid is
removed from the one quart container and lines. This
purges any residual cleaning solvent from the trans-
mission cooler and lines. Turn pump OFF.
(13) Disconnect alligator clips from battery. Recon-
nect flusher lines to cover plate, and remove flushing
adapters from cooler lines.
7s - 30 TRANSMISSIONKJ

economy, and/or trip odometer data has been reset.
The CMTC uses internal programming, hard wired
inputs from the U.S./Metric and Reset switches, and
electronic messages received from the Body Control
Module (BCM) to determine the proper reset mes-
sages to send to the EMIC.
²Door Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the Body Control Module (BCM) indi-
cating that the status of any door ajar input has
changed from closed to not closed, and from the PCM
indicating that the vehicle is moving. The BCM uses
internal programming, and hard wired inputs from
the door ajar switches and the ignition switch to
determine the proper door ajar switch messages to
send to the EMIC. The PCM uses internal program-
ming and a hard wired vehicle speed pulse input
received from the BCM to determine the proper vehi-
cle distance messages to send to the EMIC.
²Electrical System Voltage Low or High
Warning- Each time the ignition switch is turned to
the On position, the EMIC chime tone generator will
generate a single ªbong-likeº chime tone the first
time an electronic message is received over the PCI
data bus from the PCM requesting ªChargingº indi-
cator illumination. This warning would indicate that
the monitored electrical system voltage is either too
low or too high. This warning will only occur once
during an ignition cycle. The PCM uses internal pro-
gramming and hard wired inputs from the electrical
and charging systems to determine the proper
ªChargingº indicator messages to send to the EMIC.
²Engine Coolant Temperature High Warning
- Each time the ignition switch is turned to the On
position, the EMIC chime tone generator will gener-
ate ªbong-likeº chime tones the first time an elec-
tronic message is received over the PCI data bus
from the PCM indicating that the engine coolant
temperature is too high. This chime will sound for
five consecutive single tones, unless an electronic
message is received from the PCM indicating that
the engine coolant temperature is not too high, or
unless the ignition switch is turned to the Off posi-
tion before the five single tones have completed. The
PCM uses internal programming and a hard wired
input from the engine coolant temperature sensor to
determine the proper engine coolant temperature
messages to send to the EMIC.
²Engine Oil Pressure Low Warning- Each
time the ignition switch is turned to the On position,
the EMIC chime tone generator will generate a sin-
gle ªbong-likeº chime tone the first time three
sequential sets of electronic messages are received
over the PCI data bus from the PCM indicating thatthe engine oil pressure is too low with the engine
running. The PCM uses internal programming and
hard wired inputs from the oil pressure sensor and
the crankshaft position sensor to determine the
proper oil pressure and engine speed messages to
send to the EMIC.
²Fasten Seat Belt Warning- Each time the
ignition switch is turned to the On position, the
EMIC chime tone generator will generate repetitive
ªbong-likeº chime tones at a slow rate the first time
an electronic message is received over the PCI data
bus from the ACM requesting ªSeatbeltº indicator
illumination. The ACM uses internal programming
and hard wired inputs from the driver side front seat
belt switch and the ignition switch to determine that
the driver side front seat belt is not fastened with
the ignition switch in the On position. These chimes
will continue to sound for a duration of about six sec-
onds each time the ignition switch is turned to the
On position, or until the driver side front seat belt is
fastened, whichever occurs first. This audible warn-
ing occurs independent of the visual warning pro-
vided by the EMIC ªSeatbeltº indicator.
²Gate Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the BCM indicating that the status of
the tailgate ajar input has changed from closed to
not closed, and from the PCM indicating that the
vehicle is moving. The BCM uses internal program-
ming, and hard wired inputs from the tailgate ajar
switch and the ignition switch to determine the
proper tailgate ajar switch messages to send to the
EMIC. The PCM uses internal programming and a
hard wired vehicle speed pulse input received from
the BCM to determine the proper vehicle distance
messages to send to the EMIC.
²Glass Ajar Warning- The EMIC chime tone
generator will generate a single ªbong-likeº chime
tone when the ignition switch is in the On position,
and electronic messages are received over the PCI
data bus from the BCM indicating that the status of
the rear flip-up glass ajar input has changed from
closed to not closed, and from the PCM indicating
that the vehicle is moving. The BCM uses internal
programming, and hard wired inputs from the flip-up
glass ajar switch and the ignition switch to deter-
mine the proper flip-up glass ajar switch messages to
send to the EMIC. The PCM uses internal program-
ming and a hard wired vehicle speed pulse input
received from the BCM to determine the proper vehi-
cle distance messages to send to the EMIC.
²Head/Park/Fog Lights-On Warning- The
EMIC chime tone generator will generate repetitive
ªbong-likeº chime tones at a fast rate when the igni-
KJCHIME/BUZZER 8B - 3
CHIME WARNING SYSTEM (Continued)

tion switch is in any position except On, and elec-
tronic messages are received over the PCI data bus
from the BCM indicating that the exterior lights are
On with the ignition switch in any position except
On, and the status of the driver side front door is not
closed. The BCM uses internal programming and
hard wired inputs from the left (lighting) control
stalk of the multi-function switch, the ignition
switch, and the driver side front door ajar switch to
determine the proper messages to send to the EMIC.
These chimes will continue to sound until the exte-
rior lighting is turned Off, until the ignition switch is
turned to the On position, or until the status of the
driver side front door ajar input changes from not
closed to closed, whichever occurs first.
²Key-In-Ignition Warning- The EMIC chime
tone generator will generate repetitive ªbong-likeº
chime tones at a fast rate when the ignition switch is
in any position except On, and electronic messages
are received over the PCI data bus from the BCM
indicating that the key is in the ignition lock cylinder
with the ignition switch in any position except On,
and the driver side front door is not closed. The BCM
internal programming and hard wired inputs from
the key-in ignition circuitry of the ignition switch,
the ignition switch, and the driver side front door
ajar switch to determine the proper messages to send
to the EMIC. These chimes will continue to sound
until the key is removed from the ignition lock cylin-
der, until the ignition switch is turned to the On
position, or until the status of the driver side front
door ajar input changes from not closed to closed,
whichever occurs first.
²Low Coolant Warning- On vehicles equipped
with a diesel engine, the EMIC chime tone generator
will generate a single ªbong-likeº chime tone when
the ignition switch is first turned to the On position
and a hard wired input from the engine coolant level
sensor to the EMIC indicates that the coolant level is
low for more than about one-quarter second. Any
time after the ignition switch is first turned to the
On position, the EMIC uses internal programming to
check the status of the engine coolant level sensor
inputs about once every second, then adjusts an
internal counter up or down based upon the status of
this input. When the counter accumulates thirty
inputs indicating that the coolant level is low, a sin-
gle chime tone is sounded. This strategy is intended
to reduce the effect that coolant sloshing within the
coolant reservoir can have on reliable chime warning
operation. This warning will only occur once during
an ignition cycle.
²Low Fuel Warning- Each time the ignition
switch is turned to the On position, the EMIC chime
tone generator will generate a single ªbong-likeº
chime tone the first time an electronic message isreceived over the PCI data bus from the PCM
requesting ªLow Fuelº indicator illumination. The
chime will only occur a second time during the same
ignition cycle if another electronic message has been
received from the PCM indicating that there is an
increase in the fuel level equal to about 3 liters (0.8
gallon), then a subsequent electronic message from
the PCM requests ªLow Fuelº indicator illumination.
This strategy combined with filtering performed by
the internal programming of the PCM on the fuel
tank sending unit input is intended to reduce the
possibility of fuel sloshing within the fuel tank caus-
ing multiple low fuel warning chimes during a given
ignition cycle. The EMIC will also respond with the
low fuel warning chime when electronic fuel level
messages are received from the PCM indicating that
the hard wired input to the PCM from the fuel tank
sending unit is an open circuit (greater than full), or
a short circuit (less than empty).
²Low Washer Fluid Warning- The EMIC
chime tone generator will generate a single ªbong-
likeº chime tone when the ignition switch is turned
to the On position and a hard wired input from the
washer fluid level switch to the EMIC indicates the
washer fluid is low for more than about one-quarter
second. Any time after the ignition switch is first
turned to the On position, the EMIC uses internal
programming to check the status of the washer fluid
level switch inputs about once every second, then
adjusts an internal counter up or down based upon
the status of this input. When the counter accumu-
lates thirty inputs indicating that the washer fluid
level is low, a single chime tone is sounded. This
strategy is intended to reduce the effect that fluid
sloshing within the washer reservoir can have on
reliable chime warning operation. This warning will
only occur once during an ignition cycle.
²Overspeed Warning- The EMIC chime tone
generator will generate repetitive ªbong-likeº chime
tones at a slow rate when the ignition switch is in
the On position, and an electronic message received
over the PCI data bus from the PCM indicates that
the vehicle speed is over a programmed speed value.
The PCM uses internal programming and distance
pulse information received over a hard wired vehicle
speed pulse input from the BCM to determine the
proper vehicle speed messages to send to the EMIC.
The BCM uses an internally programmed electronic
pinion factor and a hard wired input from the rear
wheel speed sensor to calculate the proper distance
pulse information to send to the PCM. The electronic
pinion factor represents the proper tire size and axle
ratio information for the vehicle. These chimes will
continue to sound until the vehicle speed messages
are below the programmed speed value, or until the
ignition switch is turned to the Off position, which-
8B - 4 CHIME/BUZZERKJ
CHIME WARNING SYSTEM (Continued)

There are two different versions of the BCM: base
and premium. The base BCM is a subset of the com-
ponents in the premium version. Basically, the base
version BCM does not support the following features:
Compass Mini-Trip Computer (CMTC), fog lamps
(front and/or rear), Remote Keyless Entry (RKE),
remote radio switches, or Vehicle Theft Security Sys-
tem (VTSS). Both versions of the BCM utilize inte-
grated circuitry and information carried on the
Programmable Communications Interface (PCI) databus network along with many hard wired inputs to
monitor many sensor and switch inputs throughout
the vehicle. In response to those inputs, the internal
circuitry and programming of the BCM allow it to
control and integrate many electronic functions and
features of the vehicle through both hard wired out-
puts and the transmission of electronic message out-
puts to other electronic modules in the vehicle over
the PCI data bus. The electronic functions and fea-
tures that the BCM supports or controls include the
following:
²A/C Select Switch Status- The BCM monitors
an input from, and transmits the status of the A/C
switch on the heater-A/C control.
²Ambient Temperature Data- The premium
BCM monitors and transmits the ambient tempera-
ture sensor input data.
²Cargo Lamp Disable- The BCM monitors an
input from the cargo lamp switch to provide an inte-
rior lighting disable feature.
²Chimes- The chime tone generator is located
on the ElectroMechanical Instrument Cluster (EMIC)
circuit board, but the EMIC goes to sleep with the
ignition switch in the Off position. The BCM provides
a wake-up output to the EMIC based upon inputs
from the key-in ignition switch or the exterior light-
ing switch, then sends electronic chime request mes-
sages to the EMIC for the headlamps-on warning
and key-in ignition warning.
²Door Lock Inhibit- The BCM monitors the
key-in ignition switch and the driver side front door
ajar switch to provide a door lock inhibit feature.
²Exterior Lamp Load Shedding- The BCM
provides a battery saver feature which will automat-
ically turn off exterior lamps that remain on after a
timed interval.
²Exterior Lamp Status- The BCM monitors
the status of the park lamp, low beam, high beam or
Daytime Running Lamp (DRL - Canada only), front
fog lamp (optional), and rear fog lamp (in required
markets only) relays.
²Exterior Lighting Control- The BCM pro-
vides exterior lamp control for standard head and
park lamps, as well as Daytime Running Lamps
(DRL - Canada only), front fog lamps (optional), and
rear fog lamps (in required markets only). This
includes support for features including optical horn
(also known as flash-to-pass) and headlamp time
delay.
²Flip-Up Glass Control- The BCM monitors
the tailgate cylinder lock switch, the tailgate handle
switch, the Remote Keyless Entry (RKE) module
inputs and the rear wiper switch to provide control
for the rear flip-up glass actuator.
Fig. 1 Body Control Module Location
1 - DRIVER DOOR
2 - INSTRUMENT PANEL END BRACKET
3 - JUNCTION BLOCK
4 - BODY CONTROL MODULE
Fig. 2 Body Control Module
1 - BODY CONTROL MODULE (FRONT VIEW)
2 - REMOTE KEYLESS ENTRY MODULE RECEPTACLE
3 - BCM-RKE CONNECTOR
4 - BODY CONTROL MODULE (BACK VIEW)
5 - JB-BCM CONNECTOR
6 - CONNECTOR RECEPTACLE (2)
KJELECTRONIC CONTROL MODULES 8E - 3
BODY CONTROL MODULE (Continued)

no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 60.7 to 80.3 ohms. If OK, go to
Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test in this
group. If not OK, replace the faulty relay.
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the rear glass and outside rear view mirror heat-
ing grids and the defogger switch indicator lamp.
There should be continuity between the cavity for
relay terminal 87 and the rear window defogger relay
output circuit cavities of the rear glass heating grid
connector, both outside rear view mirror heating grid
connectors, and the defogger switch connector at all
times. If OK, go to Step 4. If not OK, repair the open
circuit(s) as required.(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. This terminal is pro-
vided with ground by the instrument cluster rear
window defogger timer and logic circuitry to energize
the defogger relay. There should be continuity to
ground at the cavity for relay terminal 85 when the
defogger switch is turned On. However, with the
defogger relay removed, the defogger switch indicator
lamp will not light to show that the defogger system
is turned On. Be certain that you depress the defog-
ger switch at least twice to confirm that the system
is turned on during this test. If OK, go to Step 5. If
not OK, repair the open circuit to the HVAC control
head as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to
fused ignition switch output voltage and should be
hot when the ignition switch is in the run position.
Check for battery voltage at the cavity for relay ter-
minal 86 with the ignition switch in the run position.
If OK, see the diagnosis for Instrument Cluster in
this group. If not OK, repair the open circuit to the
fuse in the junction block as required.
REMOVAL
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the rear window defogger relay from
the junction block.
INSTALLATION
(1) Install the rear window defogger relay by align-
ing the relay terminals with the cavities in the junc-
tion block and pushing the relay firmly into place.
(2) Connect the battery negative cable.
(3) Test the relay operation.
Fig. 4 DEFOGGER RELAY- TERMINAL LEGEND
KJWINDOW DEFOGGER 8G - 7
REAR WINDOW DEFOGGER RELAY (Continued)

REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is installed in the
instrument panel HVAC contol head assembly. The
momentary-type switch provides a hard-wired ground
signal to the HVAC control head each time it is
depressed. The instrument cluster rear window
defogger timer and logic circuitry responds by ener-
gizing or de-energizing the rear window defogger
relay.
OPERATION
Energizing the rear window defogger relay pro-
vides electrical current to the rear window defogger
grid and, if the vehicle is so equipped, the outside
rear view mirror heating grids. An amber indicator
lamp in the defogger switch, which lights to indicate
when the defogger system is turned On, is also pow-
ered by the defogger relay output.
The defogger switch illumination lamp and indica-
tor lamp bulbs are serviceable. The defogger switch
cannot be repaired and, if faulty or damaged the
entire HVAC control head assembly must be
replaced.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the HVAC control head assembly from
the instrument panel and unplug the defogger switch
wire harness connector-B.
(2) Check for continuity between the ground cir-
cuit cavity of the defogger switch wire harness con-nector and a good ground. There should be
continuity. If OK, go to Step 3. If not OK, repair the
open circuit as required.
(3) Check for continuity between the ground cir-
cuit terminal and the rear window defogger switch
sense circuit terminal on the back of the defogger
switch housing (Fig. 5). There should be momentary
continuity as the defogger switch button is depressed,
and then no continuity. If OK, (Refer to 8 - ELEC-
TRICAL/HEATED GLASS/REAR WINDOW DEFOG-
GER SWITCH - DIAGNOSIS AND TESTING -
INSTRUMENT CLUSTER REAR WINDOW DEFOG-
GER FUNCTION) If not OK, replace the faulty
switch (Fig. 5).
(4) Check switch position continuity between:
CONTACT PINS
1 - OFF LAMPS A-1 - A-7
2 - ON MOMENTARY B-6 - B-8
3 - ILLUMINATION LAMP A-7 - A-1
4 - INDICATOR LAMP B-12 - B-7
Fig. 5 A/C HEATER CONTROL HEAD (Rear View)
1 - A/C HEATER CONTROL HEAD
2 - A/C HEATER CONTROL HEAD LIGHT
3 - REAR WINDOW DEFOGGER SWITCH AND TEMPERATURE
BLEND DOOR- CONNECTOR B (12 PIN)
4 - A/C HEATER CONTROL HEAD LIGHT
5 - MODE SELECT CONTROL
6 - BLOWER SPEED CONTROL- CONNECTOR A (7 PIN)
7 - MOUNTING SCREWS (4)
8G - 8 WINDOW DEFOGGERKJ

perform its many functions. The EMIC module incor-
porates a blue-green digital Vacuum Fluorescent Dis-
play (VFD) for displaying odometer and trip
odometer information, as well as several warning
messages and certain diagnostic information. In addi-
tion to instrumentation and indicators, the EMIC has
the hardware and software needed to provide the fol-
lowing features:
²Chime Warning Service- A chime tone gener-
ator on the EMIC electronic circuit board provides
audible alerts to the vehicle operator and eliminates
the need for a separate chime module. (Refer to 8 -
ELECTRICAL/CHIME WARNING SYSTEM -
DESCRIPTION).
²Panel Lamps Dimming Service- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of the radio display, gear selector indicator, heater-air
conditioner control, and all other dimmable lighting
on the panel lamps dimmer circuit with that of the
cluster illumination lamps and VFD.
The EMIC houses four analog gauges and has pro-
visions for up to twenty-four indicators (Fig. 2). The
EMIC includes the following analog gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Speedometer
²Tachometer
Some of the EMIC indicators are automatically
configured when the EMIC is connected to the vehi-
cle electrical system for compatibility with certain
optional equipment or equipment required for regula-
tory purposes in certain markets. While each EMIC
may have provisions for indicators to support every
available option, the configurable indicators will not
be functional in a vehicle that does not have the
equipment that an indicator supports. The EMIC
includes provisions for the following indicators (Fig.
2):
²Airbag Indicator (with Airbag System only)
²Antilock Brake System (ABS) Indicator
(with ABS only)
²Brake Indicator
²Charging Indicator
²Coolant Low Indicator (with Diesel Engine
only)
²Cruise Indicator (with Speed Control Sys-
tem only)
²Four-Wheel Drive Full Time Indicator (with
Selec-Trac Transfer Case only)
²Four-Wheel Drive Low Mode Indicator
²Four-Wheel Drive Part Time Indicator
²Front Fog Lamp Indicator (with Front Fog
Lamps only)
²High Beam Indicator
²Low Fuel Indicator²Low Oil Pressure Indicator
²Malfunction Indicator Lamp (MIL)
²Overdrive-Off Indicator (with Automatic
Transmission only)
²Rear Fog Lamp Indicator (with Rear Fog
Lamps only)
²Seatbelt Indicator
²Security Indicator (with Vehicle Theft
Security System only)
²Sentry Key Immobilizer System (SKIS)
Indicator (with SKIS only)
²Transmission Overtemp Indicator (with
Automatic Transmission only)
²Turn Signal (Right and Left) Indicators
²Wait-To-Start Indicator (with Diesel Engine
only)
²Water-In-Fuel Indicator (with Diesel Engine
only)
Each indicator in the EMIC is illuminated by a
dedicated Light Emitting Diode (LED) that is sol-
dered onto the EMIC electronic circuit board. The
LEDs are not available for service replacement and,
if damaged or faulty, the entire EMIC must be
replaced. Cluster illumination is accomplished by
dimmable incandescent back lighting, which illumi-
nates the gauges for visibility when the exterior
lighting is turned on. Each of the incandescent bulbs
is secured by an integral bulb holder to the electronic
circuit board from the back of the cluster housing.
The incandescent bulb/bulb holder units are available
for service replacement.
Hard wired circuitry connects the EMIC to the
electrical system of the vehicle. These hard wired cir-
cuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system
and to the EMIC through the use of a combination of
soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
The EMIC modules for this model are serviced only
as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator,
the VFD, the electronic circuit board, the circuit
board hardware, the cluster overlay, or the EMIC
housing are damaged or faulty, the entire EMIC mod-
ule must be replaced. The cluster lens, hood and
mask unit and the individual incandescent lamp
bulbs with holders are available for service replace-
ment.
KJINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

gauge readings during normal operation that are con-
sistent with customer expectations. However, when
abnormal conditions exist such as high coolant tem-
perature, the algorithm can drive the gauge pointer
to an extreme position and the microprocessor can
sound a chime through the on-board chime tone gen-
erator to provide distinct visual and audible indica-
tions of a problem to the vehicle operator. The
instrument cluster circuitry may also perform chime
service for other electronic modules in the vehicle
based upon electronic chime tone request messages
received over the PCI data bus to provide the vehicle
operator with an audible alert to supplement a visual
indication. One such alert is a door ajar warning
chime, which the EMIC provides by monitoring PCI
bus messages from the Body Control Module (BCM).
The EMIC circuitry operates on battery current
received through a fused B(+) fuse in the Junction
Block (JB) on a non-switched fused B(+) circuit, and
on battery current received through a fused ignition
switch output (run-start) fuse in the JB on a fused
ignition switch output (run-start) circuit. This
arrangement allows the EMIC to provide some fea-
tures regardless of the ignition switch position, while
other features will operate only with the ignition
switch in the On or Start positions. The EMIC
receives a ground input from the BCM as a wake-up
signal in order to provide the ignition-off features.
The EMIC circuitry is grounded through a ground
circuit and take out of the instrument panel wire
harness with an eyelet terminal connector that is
secured by a nut to a ground stud located on the left
instrument panel end bracket.
The EMIC also has a self-diagnostic actuator test
capability, which will test each of the PCI bus mes-
sage-controlled functions of the cluster by lighting
the appropriate indicators (except the airbag indica-
tor), sweeping the gauge needles to several calibra-
tion points across the gauge faces, and stepping the
odometer display sequentially from all ones through
all nines. (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). See the
owner's manual in the vehicle glove box for more
information on the features, use and operation of the
EMIC.
GAUGES All gauges receive battery current
through the EMIC circuitry when the ignition switch
is in the On or Start positions. With the ignition
switch in the Off position battery current is not sup-
plied to any gauges, and the EMIC circuitry is pro-
grammed to move all of the gauge needles back to
the low end of their respective scales. Therefore, the
gauges do not accurately indicate any vehicle condi-
tion unless the ignition switch is in the On or Start
positions. All of the EMIC gauges, except the odome-
ter, are air core magnetic units. Two fixed electro-magnetic coils are located within each gauge. These
coils are wrapped at right angles to each other
around a movable permanent magnet. The movable
magnet is suspended within the coils on one end of a
pivot shaft, while the gauge needle is attached to the
other end of the shaft. One of the coils has a fixed
current flowing through it to maintain a constant
magnetic field strength. Current flow through the
second coil changes, which causes changes in its
magnetic field strength. The current flowing through
the second coil is changed by the EMIC circuitry in
response to messages received over the PCI data bus.
The gauge needle moves as the movable permanent
magnet aligns itself to the changing magnetic fields
created around it by the electromagnets.
The gauges are diagnosed using the EMIC self-di-
agnostic 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 gauge require the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation. Specific operation details for each gauge may
be found elsewhere in this service information.
VACUUM-FLUORESCENT DISPLAY The Vacu-
um-Fluorescent Display (VFD) module is soldered to
the EMIC circuit board. The display is active when
the driver door is opened with the ignition switch in
the Off or Accessory positions (Rental Car mode), and
with the ignition switch in the On or Start positions.
The VFD is inactive when the ignition switch is in
the Off or Accessory positions and the driver door is
closed. The illumination intensity of the VFD is con-
trolled by the EMIC circuitry based upon electronic
dimming level messages received from the BCM over
the PCI data bus, and is synchronized with the illu-
mination intensity of other VFDs in the vehicle. The
BCM provides dimming level messages based upon
internal programming and inputs it receives from the
control knob and control ring on the left (lighting)
control stalk of the multi-function switch on the
steering column.
The VFD has several display capabilities including
odometer, trip odometer, and warning messages
whenever the appropriate conditions exist. The VFD
warning messages include:
²ªdoorº- indicating a door is ajar.
²ªgateº- indicating the tailgate is ajar.
²ªglassº- indicating the tailgate glass is ajar.
²ªlowashº- indicating that the washer fluid
level is low.
²ªno busº- indicating there is no PCI data bus
communication detected.
An odometer/trip odometer switch on the EMIC cir-
cuit board is used to control the display modes. This
switch is actuated manually by depressing the odom-
KJINSTRUMENT CLUSTER 8J - 5
INSTRUMENT CLUSTER (Continued)