2002 JEEP LIBERTY immobilizer

ever occurs first. The overspeed warning feature is
only enabled on a BCM that has been programmed
with a Middle East Gulf Coast Country (GCC) coun-
try code.
²No Airbag Indicator Message Warning- The
EMIC chime tone generator will generate one, short,
ªbong-likeº chime tone and turn on the ªAirbagº indi-
cator when the ignition switch is in the On position,
and a PCI data bus ªAirbagº indicator on or off mes-
sage is not received from the ACM for six consecutive
seconds.
²No Antilock Brake Indicator Message Warn-
ing- The EMIC chime tone generator will generate
one, short, ªbong-likeº chime tone and turn on the
ªABSº indicator when the ignition switch is in the On
position, and a PCI data bus ªABSº indicator on or
off message is not received from the CAB for six con-
secutive seconds.
²No Fuel Level Message Warning- The EMIC
chime tone generator will generate one, short, ªbong-
likeº chime tone and turn on the ªLow Fuelº indica-
tor when the ignition switch is in the On position,
and a PCI data bus fuel level message is not received
from the PCM for twelve consecutive seconds.
²Remote Keyless Entry Transmitter Pro-
gramming- On vehicles so equipped, the EMIC
chime tone generator will generate a single ªbong-
likeº chime tone when an electronic message is
received over the PCI data bus from the BCM indi-
cating that a Remote Keyless Entry (RKE) transmit-
ter has been successfully programmed by the
customer into the RKE module memory.
²Sentry Key Immobilizer System Transpon-
der Programming- On vehicles so equipped, the
EMIC chime tone generator will generate a single
ªbong-likeº chime tone when an electronic message is
received over PCI data bus message from the Sentry
Key Immobilizer Module (SKIM) indicating that the
Sentry Key Immobilizer System (SKIS) has been
placed in the ªCustomer Learnº programming mode,
and again each time a new SKIS transponder has
been successfully programmed by the customer.
²Turn Signal Cancel Warning- The EMIC
chime tone generator will generate repetitive ªbong-
likeº chime tones at a slow rate when the vehicle is
driven for a distance of about 3.2 kilometers (about
two miles) with a turn signal indicator flashing. The
EMIC uses an electronic message received over the
PCI data bus from the PCM, and a hard wired input
from the turn signal switch circuitry of the multi-
function switch to determine when to sound the turn
signal cancel warning. The PCM uses internal pro-
gramming 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 internallyprogrammed electronic pinion factor and a hard
wired input from the rear wheel speed sensor to cal-
culate 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 turn signal is turned Off, until the hazard warn-
ing system is turned On, or until the ignition switch
is turned to the Off position, whichever occurs first.
²Water-In-Fuel Warning- On vehicles equipped
with a diesel engine, each time the ignition switch is
turned to the On position, the EMIC chime tone gen-
erator 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 ªWater-
in-Fuelº indicator illumination. The PCM uses inter-
nal programming and a hard wired input from the
water-in-fuel sensor to determine the proper water-
in-fuel messages to send to the EMIC. This warning
will only occur once during an ignition cycle.
The EMIC provides chime service for all available
features in the chime warning system. The EMIC
relies upon its internal programming and hard wired
inputs from the turn signal (multi-function) switch,
the washer fluid level switch, and the engine coolant
level sensor (diesel engine only) to provide chime ser-
vice for the turn signal cancel warning, the low
washer fluid warning, and the low coolant warning
respectively. The EMIC relies upon electronic mes-
sage inputs received from other electronic modules
over the PCI data bus network to provide chime ser-
vice for all of the remaining chime warning system
features. Upon receiving the proper inputs, the EMIC
activates the integral chime tone generator to pro-
vide the audible chime warning to the vehicle opera-
tor. The internal programming of the EMIC
determines the priority of each chime request input
that is received, as well as the rate and duration of
each chime tone that is to be generated. See the own-
er's manual in the vehicle glove box for more infor-
mation on the features provided by the chime
warning system.
The hard wired chime warning system inputs to
the EMIC, as well as other hard wired circuits for
this system may be diagnosed and tested using con-
ventional diagnostic tools and procedures. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the EMIC, the PCI data
bus network, or the electronic message inputs used
by the EMIC to provide chime warning system ser-
vice. The most reliable, efficient, and accurate means
to diagnose the EMIC, the PCI data bus network,
and the electronic message inputs for the chime
warning system requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
KJCHIME/BUZZER 8B - 5
CHIME WARNING SYSTEM (Continued)

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
ELECTRONIC CONTROL MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING.......................1
BODY CONTROL MODULE
DESCRIPTION..........................2
OPERATION............................5
DIAGNOSIS AND TESTING - BODY CONTROL
MODULE.............................7
REMOVAL.............................7
INSTALLATION..........................7
COMMUNICATION
DESCRIPTION..........................8
OPERATION............................8
CONTROLLER ANTILOCK BRAKE
REMOVAL.............................10
INSTALLATION.........................10
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR....10
OPERATION - DATA LINK CONNECTOR......10
POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION - PCM..................11
DESCRIPTION - MODES OF OPERATION . . . 11
DESCRIPTION - 5 VOLT SUPPLIES.......13
DESCRIPTION - IGNITION CIRCUIT SENSE . 13DESCRIPTION - POWER GROUNDS......13
DESCRIPTION - SENSOR RETURN.......14
OPERATION
OPERATION - PCM....................14
OPERATION - 5 VOLT SUPPLIES.........15
OPERATION - IGNITION CIRCUIT SENSE . . . 15
REMOVAL.............................15
INSTALLATION.........................15
SENTRY KEY IMMOBILIZER MODULE
DESCRIPTION.........................15
OPERATION...........................16
REMOVAL.............................17
INSTALLATION.........................18
TRANSMISSION CONTROL MODULE
DESCRIPTION.........................18
OPERATION...........................18
STANDARD PROCEDURE - TCM QUICK
LEARN..............................21
HEATED SEAT MODULE
DESCRIPTION.........................21
OPERATION...........................21
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE............................22
REMOVAL.............................24
INSTALLATION.........................24
ELECTRONIC CONTROL
MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING
NOTE: Before replacing the PCM for a failed driver,
control circuit, or ground circuit, be sure to check
the related component/circuit integrity for failures
not detected due to a double fault in the circuit.
Most PCM driver/control circuit failures are caused
by internal component failures (i.e. relays and sole-
noids) and shorted circuits (i.e. pull-ups, drivers,
and switched circuits). These failures are difficult to
detect when a double fault has occurred and only
one DTC has been set.
When a PCM (JTEC) and the SKIM are replaced
at the same time, perform the following steps in
order:
(1) Program the new PCM (JTEC).(2) Program the new SKIM.
(3) Replace all ignition keys and program them to
the new SKIM.
PROGRAMMING THE PCM (JTEC)
The SKIS Secret Key is an ID code that is unique
to each SKIM. This code is programmed and stored
in the SKIM, the PCM, and the ignition key tran-
sponder chip(s). When replacing the PCM, it is nec-
essary to program the secret key into the new PCM
using the DRBIIItscan tool. Perform the following
steps to program the secret key into the PCM.
(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Enter secured access mode by entering the
vehicle four-digit PIN.
(5) Select ENTER to update PCM VIN.
KJELECTRONIC CONTROL MODULES 8E - 1

²Transmission convertor clutch circuit. Driven
through J1850 circuits.
OPERATION - 5 VOLT SUPPLIES
Primary 5±volt supply:
²supplies the required 5 volt power source to the
Crankshaft Position (CKP) sensor.
²supplies the required 5 volt power source to the
Camshaft Position (CMP) sensor.
²supplies a reference voltage for the Manifold
Absolute Pressure (MAP) sensor.
²supplies a reference voltage for the Throttle
Position Sensor (TPS) sensor.
Secondary 5±volt supply:
²supplies the required 5 volt power source to the
oil pressure sensor.
²supplies the required 5 volt power source for the
Vehicle Speed Sensor (VSS) (if equipped).
²supplies the 5 volt power source to the transmis-
sion pressure sensor (certain automatic transmis-
sions).
OPERATION - IGNITION CIRCUIT SENSE
The ignition circuit sense input tells the PCM the
ignition switch has energized the ignition circuit.
Battery voltage is also supplied to the PCM
through the ignition switch when the ignition is in
the RUN or START position. This is referred to as
the9ignition sense9circuit and is used to9wake up9
the PCM. Voltage on the ignition input can be as low
as 6 volts and the PCM will still function. Voltage is
supplied to this circuit to power the PCM's 8-volt reg-
ulator and to allow the PCM to perform fuel, ignition
and emissions control functions.
REMOVAL
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
The PCM is located in the engine compartment
near the battery (Fig. 9).
To avoid possible voltage spike damage to the
PCM, ignition key must be off, and negative battery
cable must be disconnected before unplugging PCM
connectors.
(1) Disconnect negative battery cable at battery.
(2) Remove cover over electrical connectors. Cover
snaps onto PCM.
(3) Carefully unplug the three 32±way connectors
from PCM.
(4) Remove three PCM mounting bolts and remove
PCM from vehicle.
INSTALLATION
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
(1) Install PCM and 3 mounting bolts to vehicle.
(2) Tighten bolts. Refer to torque specifications.
(3) Check pin connectors in the PCM and the three
32±way connectors for corrosion or damage. Also, the
pin heights in connectors should all be same. Repair
as necessary before installing connectors.
(4) Install three 32±way connectors.
(5) Install cover over electrical connectors. Cover
snaps onto PCM.
(6) Install battery cable.
(7) Use the DRB scan tool to reprogram new PCM
with vehicles original Identification Number (VIN)
and original vehicle mileage.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) is the
primary component of the Sentry Key Immobilizer
System (SKIS) (Fig. 10). The SKIM is located on the
right side of the steering column, below the ignition
Fig. 9 PCM REMOVE/INSTALL
1 - PCM
2 - MOUNTING BOLTS (3)
3 - 32-WAY CONNECTORS
KJELECTRONIC CONTROL MODULES 8E - 15
POWERTRAIN CONTROL MODULE (Continued)

lock cylinder housing and is concealed beneath the
steering column shrouds. The molded black plastic
housing for the SKIM has an integral molded plastic
halo-like antenna ring that extends from one end.
When the SKIM is properly installed on the steering
column, the antenna ring is oriented around the cir-
cumference of the ignition lock cylinder housing. A
single integral connector receptacle containing six
terminal pins is located on the opposite end of the
SKIM housing from the antenna ring. A stamped
metal mounting bracket secured to the SKIM hous-
ing has a U-shaped clip formation that is used to
secure the unit to the right lower flange of the steer-
ing column jacket.
The SKIM cannot be adjusted or repaired. If faulty
or damaged, the entire SKIM unit must be replaced.
OPERATION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a
microprocessor. The SKIM transmits RF signals to,
and receives RF signals from the Sentry Key tran-
sponder through a tuned antenna enclosed within the
molded plastic antenna ring integral to the SKIM
housing. If this antenna ring is not mounted properly
around the ignition lock cylinder housing, communi-
cation problems between the SKIM and the transpon-
der may arise. These communication problems will
result in Sentry Key transponder-related faults. The
SKIM also communicates over the Programmable
Communications Interface (PCI) data bus with the
Powertrain Control Module (PCM), the ElectroMe-
chanical Instrument Cluster (EMIC) and/or the
DRBIIItscan tool.The SKIM retains in memory the ID numbers of
any Sentry Key transponder that is programmed into
it. A maximum of eight Sentry Key transponders can
be programmed into the SKIM. For added system
security, each SKIM is programmed with a unique
Secret Key code. This code is stored in memory, sent
over the PCI data bus to the PCM, and is encoded to
the transponder of every Sentry Key that is pro-
grammed into the SKIM. Therefore, the Secret Key
code is a common element that is found in every com-
ponent of the Sentry Key Immobilizer System (SKIS).
Another security code, called a PIN, is used to gain
access to the SKIM Secured Access Mode. The
Secured Access Mode is required during service to
perform the SKIS initialization and Sentry Key tran-
sponder programming procedures. The SKIM also
stores the Vehicle Identification Number (VIN) in its
memory, which it learns through a PCI data bus
message from the PCM during SKIS initialization.
In the event that a SKIM replacement is required,
the Secret Key code can be transferred to the new
SKIM from the PCM using the DRBIIItscan tool
and the SKIS initialization procedure. Proper com-
pletion of the SKIS initialization will allow the exist-
ing Sentry Keys to be programmed into the new
SKIM so that new keys will not be required. In the
event that the original Secret Key code cannot be
recovered, SKIM replacement will also require new
Sentry Keys. The DRBIIItscan tool will alert the
technician during the SKIS initialization procedure if
new Sentry Keys are required.
When the ignition switch is turned to the On posi-
tion, the SKIM transmits an RF signal to the tran-
sponder in the ignition key. The SKIM then waits for
an RF signal response from the transponder. If the
response received identifies the key as valid, the
SKIM sends a valid key message to the PCM over
the PCI data bus. If the response received identifies
the key as invalid, or if no response is received from
the key transponder, the SKIM sends an invalid key
message to the PCM. The PCM will enable or disable
engine operation based upon the status of the SKIM
messages. It is important to note that the default
condition in the PCM is an invalid key; therefore, if
no message is received from the SKIM by the PCM,
the engine will be disabled and the vehicle immobi-
lized after two seconds of running.
The SKIM also sends SKIS indicator status mes-
sages to the EMIC over the PCI data bus to tell the
EMIC how to operate the SKIS indicator. This indi-
cator status message tells the EMIC to turn the indi-
cator on for about three seconds each time the
ignition switch is turned to the On position as a bulb
test. After completion of the bulb test, the SKIM
sends indicator status messages to the EMIC to turn
the indicator off, turn the indicator on, or to flash the
Fig. 10 Sentry Key Immobilizer Module
1 - SKIM
2 - BRACKET
3 - CONNECTOR RECEPTACLE
4 - ANTENNA RING
8E - 16 ELECTRONIC CONTROL MODULESKJ
SENTRY KEY IMMOBILIZER MODULE (Continued)

indicator on and off. If the SKIS indicator flashes
upon ignition On or stays on solid after the bulb test,
it signifies a SKIS fault. If the SKIM detects a sys-
tem malfunction and/or the SKIS has become inoper-
ative, the SKIS indicator will stay on solid. If the
SKIM detects an invalid key or if a key transponder-
related fault exists, the SKIS indicator will flash. If
the vehicle is equipped with the Customer Learn
transponder programming feature, the SKIM will
also send messages to the EMIC to flash the SKIS
indicator and to generate a single audible chime tone
whenever the Customer Learn programming mode is
being utilized. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY - STANDARD PROCEDURE -
SENTRY KEY TRANSPONDER PROGRAMMING).
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store fault information in the form of Diagnostic
Trouble Codes (DTC's) in SKIM memory if a system
malfunction is detected. The SKIM can be diagnosed,
and any stored DTC's can be retrieved using 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, 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) Disconnect and isolate the battery negative
cable.
(2) If the vehicle is equipped with the optional tilt
steering column, move the tilt steering column to the
fully lowered position and leave the tilt release lever
in the released (down) position.
(3) From below the steering column, remove the
two screws that secure the lower shroud to the upper
shroud (Fig. 11).
(4) Using hand pressure, push gently inward on
both sides of the upper shroud near the parting line
between the upper and lower shrouds to release thesnap features that secure the two halves to each
other.
(5) Remove both the upper and lower shrouds from
the steering column.
(6) Disconnect the instrument panel wire harness
connector for the SKIM from the module connector
receptacle.
(7) The SKIM mounting bracket features a clip for-
mation that secures the SKIM to the right lower
flange of the steering column jacket. Pull downward
on the connector end of the SKIM mounting bracket
to release this clip from the steering column jacket.
(8) Rotate the SKIM and its mounting bracket
downwards and then to the side away from the steer-
ing column to slide the SKIM antenna ring from
around the ignition switch lock cylinder housing. Lift
the multi-function switch upward off of the upper
steering column housing far enough to remove the
SKIM antenna ring formation from between the igni-
tion key release button and the multi-function switch
housing.
(9) Remove the SKIM from the steering column.
Fig. 11 Sentry Key Immobilizer Module Remove/
Install
1 - UPPER SHROUD
2 - STEERING COLUMN
3 - WIRE HARNESS CONNECTOR
4 - SENTRY KEY IMMOBILIZER MODULE
5 - LOWER SHROUD
6 - SCREW (2)
7 - IGNITION LOCK CYLINDER HOUSING
KJELECTRONIC CONTROL MODULES 8E - 17
SENTRY KEY IMMOBILIZER MODULE (Continued)

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 Sentry Key Immobilizer Module
(SKIM) to the right side of the steering column (Fig.
11). Lift the multi-function switch upward off of the
upper steering column housing far enough to insert
the SKIM antenna ring formation between the igni-
tion key release button and the multi-function switch
housing.
(2) Slide the SKIM antenna ring around the igni-
tion switch lock cylinder housing, then rotate the
SKIM and its mounting bracket upwards and toward
the steering column.
(3) Align the SKIM mounting bracket clip forma-
tion with the right lower flange of the steering col-
umn jacket and, using hand pressure, push upward
firmly and evenly on the connector end of the SKIM
mounting bracket to engage this clip with the steer-
ing column jacket.
(4) Reconnect the instrument panel wire harness
connector for the SKIM to the module connector
receptacle.
(5) Position both the upper and lower shrouds onto
the steering column.
(6) Align the snap features on the lower shroud
with the receptacles on the upper shroud and apply
hand pressure to snap them together.
(7) From below the steering column, install and
tighten the two screws that secure the lower shroud
to the upper shroud. Tighten the screws to 2 N´m (18
in. lbs.).
(8) If the vehicle is equipped with the optional tilt
steering column, move the tilt steering column to the
fully raised position and secure it in place by moving
the tilt release lever back to the locked (up) position.
(9) Reconnect the battery negative cable.NOTE: If the SKIM has been replaced with a new
unit, the Sentry Key Immobilizer System (SKIS)
MUST be initialized before the vehicle can be oper-
ated. (Refer to 8 - ELECTRICAL/VEHICLE THEFT
SECURITY - STANDARD PROCEDURE - SKIS INI-
TIALIZATION).
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) is located
in the engine compartment on the right (passenger)
side and is mounted to the inner fender (Fig. 12).
OPERATION
The Transmission Control Module (TCM) is the
controlling unit for all electronic operations of the
transmission. The TCM receives information regard-
ing vehicle operation from both direct and indirect
inputs, and selects the operational mode of the trans-
mission. Direct inputs are hardwired to, and used
specifically by the TCM. Indirect inputs originate
from other components/modules, and are shared with
the TCM via the vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
²Pressure Switches
²Transmission Temperature Sensor
²Input Shaft Speed Sensor
Fig. 12 Transmission Control Module Location
1 - Transmission Control Module
8E - 18 ELECTRONIC CONTROL MODULESKJ
SENTRY KEY IMMOBILIZER MODULE (Continued)

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)

wheel drive system, the four low mode indicator
lights when the transfer case is engaged in the 4L
position. On vehicles equipped with the optional
Selec-Trac four-wheel drive system, the four low
mode indicator lights when the transfer case is
engaged in the 4 Lo position. This indicator is con-
trolled by a transistor on the instrument cluster elec-
tronic circuit board based upon the cluster
programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The instrument cluster
must be configured for the type of transfer case in
the vehicle using a DRBIIItscan tool in order to pro-
vide proper operation of the four low mode indicator.
The four low mode 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 LED
will always be off when the ignition switch is in any
position except On or Start. The LED only illumi-
nates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the four low mode indicator for the fol-
lowing reasons:
²Four Low Mode Lamp-On Message- Each
time the cluster receives a four low mode lamp-on
message from the PCM indicating that a four-wheel
drive low position of the transfer case has been
selected, the four low mode indicator will be illumi-
nated. The indicator remains illuminated until the
cluster receives a four low mode 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 four low mode indica-
tor will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The PCM continually monitors the transfer case
switch to determine the driveline operating mode.
The PCM then sends the proper four low mode
lamp-on and lamp-off messages to the instrument
cluster. For further diagnosis of the four low mode
indicator or the instrument cluster circuitry that con-
trols the indicator, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the transfer case
switch, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the four low mode indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.SKIS INDICATOR
DESCRIPTION
A Sentry Key Immobilizer System (SKIS) indicator
is standard equipment on all instrument clusters, but
is only operational on vehicles equipped with the
optional SKIS. The SKIS indicator is located above
the fuel gauge and to the left of the tachometer in
the instrument cluster. The SKIS indicator consists
of a stencil-like cutout of a graphical representation
or icon of a key that is circled and crossed-out 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.
An amber Light Emitting Diode (LED) behind the
cutout in the opaque layer of the overlay causes the
indicator to appear in amber through the translucent
outer layer of the overlay when it is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The SKIS
indicator is serviced as a unit with the instrument
cluster.
OPERATION
The Sentry Key Immobilizer System (SKIS) indica-
tor gives an indication to the vehicle operator of the
status of the SKIS. This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the Sen-
try Key Immobilizer Module (SKIM) over the
Programmable Communications Interface (PCI) data
bus. The SKIS indicator Light Emitting Diode (LED)
is completely controlled by the instrument cluster
logic circuit, and that logic will only allow this indi-
cator 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 posi-
tion except On or Start. The LED only illuminates
when it is switched to ground by the instrument clus-
ter transistor. The instrument cluster will turn on
the SKIS indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position, the SKIM tells the cluster
to illuminate the SKIS indicator for about three sec-
onds as a bulb test.
²SKIS Lamp-On Message- Each time the clus-
ter receives a SKIS lamp-on message from the SKIM,
the SKIS indicator will be illuminated. The indicator
can be flashed on and off, or illuminated solid, as dic-
tated by the SKIM message. For more information on
the SKIS and the SKIS indicator control parameters,
(Refer to 8 - ELECTRICAL/VEHICLE THEFT SECU-
RITY - OPERATION). The indicator remains illumi-
nated until the cluster receives a SKIS lamp-off
KJINSTRUMENT CLUSTER 8J - 31
SHIFT INDICATOR (TRANSFER CASE) (Continued)