key JEEP LIBERTY 2002 KJ / 1.G User Guide

²RKE antenna (two circuits) - premium with
RKE only
²Tailgate ajar switch sense
²Tailgate cylinder lock switch sense
²Vehicle speed sensor
Refer to the appropriate wiring information for
additional details.
HARD WIRED OUTPUTS The hard wired outputs
of the BCM include the following:
²Courtesy lamp driver
²Courtesy lamp load shed
²Door lock relay control
²Driver door unlock relay control - premium
with RKE only
²Flip-up glass release motor driver
²Front fog lamp relay control - premium
with front fog lamps only
²Front wiper high/low relay control
²Front wiper on/off relay control
²Hazard lamp control
²High beam relay control
²Horn relay control - premium with RKE
only
²Instrument cluster wake up signal
²Low beam relay control
²Park lamp relay control
²Passenger door unlock relay control
²Rear fog lamp relay control - premium with
rear fog lamps in markets where required only
²Rear window defogger relay control
²RKE supply - premium with RKE only
²Tailgate lock driver
²Tailgate unlock driver
²Vehicle speed output
²Vehicle speed sensor supply
²VTSS indicator driver - premium with
VTSS only
Refer to the appropriate wiring information for
additional details.
GROUNDS The BCM receives ground through five
separate circuits, and also supplies a ground path to
several switches through the following hard wired
circuits:
²Ambient temperature sensor return
²Door lock switch ground
²Headlamp switch return
²Radio control mux return
²RKE ground - premium with RKE only
²Tailgate switch ground
Refer to the appropriate wiring information for
additional details.
COMMUNICATION Not including the two RKE
antenna circuits (RKE antenna + and ±), which
merely pass through the premium BCM from the
RKE module to the external RKE antenna in theinstrument panel wire harness, the BCM has the fol-
lowing communication circuits:
²PCI bus
²RKE program serial data - premium with
RKE only
²RKE transmit serial data - premium with
RKE only
Refer to the appropriate wiring information for
additional details.
MESSAGING The BCM uses the following mes-
sages received from other electronic modules over the
PCI data bus:
²Battery Temperature (PCM)
²Compass Mini-Trip Computer Button Sta-
tus (CMTC) - premium only
²Coolant Temperature (PCM)
²Distance Pulses (PCM)
²Engine Speed (PCM)
²Fuel Tank Level (PCM)
²Fuel Used (PCM)
²Intrusion Transceiver Module Commands
(ITM) - premium in markets where required
only
²Manifold Absolute Pressure (PCM)
²OK to Lock - Rolling Locks (PCM)
²SKIS Status (SKIM)
²Vehicle Identification Number (PCM)
²Vehicle Speed (PCM)
The BCM provides the following messages to other
electronic modules over the PCI data bus:
²A/C Select Switch Status (PCM)
²Country Code (EMIC, PCM, CMTC)
²Distance to Empty (CMTC) - premium only
²Door Ajar Status (EMIC)
²Exterior Lighting Status (EMIC)
²Flip-up Glass Ajar Status (EMIC)
²Fuel Economy (Average and Instantaneous)
(CMTC) - premium only
²Hood Ajar Status (ITM) - premium in mar-
kets where required only
²Ignition On Timer (CMTC) - premium only
²Intrusion Transceiver Module Commands
(ITM) - premium in markets where required
only
²Key-In Ignition Switch Status (EMIC)
²Outside Temperature (CMTC) - premium
only
²Panel Lamp Intensity (CMTC, Radio)
²Tailgate Ajar Status (EMIC)
²Radio Mode (Radio) - premium only
²Radio Preset Scan (Radio) - premium only
²Radio Seek Down (Radio) - premium only
²Radio Seek Up (Radio) - premium only
²Radio Volume Down (Radio) - premium
only
²Radio Volume Up (Radio) - premium only
8E - 6 ELECTRONIC CONTROL MODULESKJ
BODY CONTROL MODULE (Continued)

²Vacuum Fluorescent Display Synchroniza-
tion (CMTC, EMIC, Radio)
²Vehicle Theft Security System Status (PCM,
ITM) - premium only
Refer to the appropriate diagnostic information for
additional details.
DIAGNOSIS AND TESTING - BODY CONTROL
MODULE
The hard wired inputs to and outputs from the
Body Control Module (BCM), as well as other hard
wired circuits for this module may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
BCM, the Programmable Communications Interface
(PCI) data bus network, or the electronic messages
received and transmitted by the BCM over the PCI
data bus. The most reliable, efficient, and accurate
means to diagnose the BCM and the PCI data bus
network inputs to and outputs from this module
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, 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.
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.
NOTE: Before replacing a Body Control Module
(BCM), use a DRBIIITscan tool to retrieve the cur-
rent settings for the BCM programmable features
and the axle ratio/tire size (electronic pinion factor).
Refer to the appropriate diagnostic information.
These settings should be duplicated in the replace-
ment BCM using the DRBIIITscan tool before
returning the vehicle to service.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Junction Block Module (JBM) from
the instrument panel end bracket on the driver side
of the vehicle. (Refer to 8 - ELECTRICAL/POWER
DISTRIBUTION/JUNCTION BLOCK - REMOVAL).
(3) Remove the four screws that secure the BCM
to the Junction Block (JB) (Fig. 3).
(4) Remove the BCM from the JB.
(5) If the vehicle is equipped with the optional
Remote Keyless Entry (RKE) system, remove the
RKE module from the receptacle on the BCM. (Refer
to 8 - ELECTRICAL/POWER LOCKS/REMOTE KEY-
LESS ENTRY MODULE - REMOVAL).
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.
KJELECTRONIC CONTROL MODULES 8E - 7
BODY CONTROL MODULE (Continued)

NOTE: Before replacing a Body Control Module
(BCM), use a DRBIIITscan tool to retrieve the cur-
rent settings for the BCM programmable features
and the axle ratio/tire size (electronic pinion factor).
Refer to the appropriate diagnostic information.
These settings should be duplicated in the replace-
ment BCM using the DRBIIITscan tool before
returning the vehicle to service.
(1) If the vehicle is equipped with the optional
Remote Keyless Entry (RKE) system, reinstall the
RKE module into the receptacle on the BCM. (Refer
to 8 - ELECTRICAL/POWER LOCKS/REMOTE KEY-
LESS ENTRY MODULE - INSTALLATION).
(2) Position the BCM onto the Junction Block (JB)
(Fig. 3).
(3) Install and tighten the four screws that secure
the BCM to the JB. Tighten the screws to 2 N´m (18
in. lbs.).
(4) Reinstall the Junction Block Module (JBM)
onto the instrument panel end bracket on the driver
side of the vehicle. (Refer to 8 - ELECTRICAL/
POWER DISTRIBUTION/JUNCTION BLOCK -
INSTALLATION).
(5) Reconnect the battery negative cable.
COMMUNICATION
DESCRIPTION
The DaimlerChrysler Programmable Communica-
tion Interface (PCI) data bus system is a single wire
multiplex system used for vehicle communications on
many DaimlerChrysler Corporation vehicles. Multi-
plexing is a system that enables the transmission of
several messages over a single channel or circuit. All
DaimlerChrysler vehicles use this principle for com-
munication between various microprocessor-based
electronic control modules. The PCI data bus exceeds
the Society of Automotive Engineers (SAE) J1850
Standard for Class B Multiplexing.
Many of the electronic control modules in a vehicle
require information from the same sensing device. In
the past, if information from one sensing device was
required by several controllers, a wire from each con-
troller needed to be connected in parallel to that sen-
sor. In addition, each controller utilizing analog
sensors required an Analog/Digital (A/D) converter in
order to9read9these sensor inputs. Multiplexing
reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
In addition to reducing wire harness complexity,
component sensor current loads and controller hard-
ware, multiplexing offers a diagnostic advantage. A
multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. The DaimlerChrysler system allows an
electronic control module to broadcast message data
out onto the bus where all other electronic control
modules can9hear9the messages that are being sent.
When a module hears a message on the data bus
that it requires, it relays that message to its micro-
processor. Each module ignores the messages on the
data bus that are being sent to other electronic con-
trol modules.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The wire colors used for the PCI
data bus circuits are yellow with a violet tracer, or
violet with a yellow tracer, depending upon the appli-
cation. The PCI data bus messages are carried over
the bus in the form of Variable Pulse Width Modu-
lated (VPWM) signals. The PCI data bus speed is an
average 10.4 Kilo-bits per second (Kbps). By compar-
Fig. 3 Body Control Module Remove/Install
1 - SCREW (4)
2 - RKE MODULE
3 - BODY CONTROL MODULE
4 - JUNCTION BLOCK
8E - 8 ELECTRONIC CONTROL MODULESKJ
BODY CONTROL MODULE (Continued)

POWERTRAIN CONTROL
MODULE
DESCRIPTION
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 8). The PCM is
referred to as JTEC.
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
During Open Loop modes, the PCM receives input
signals and responds only according to preset PCM
programming. Input from the oxygen (O2S) sensors
is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:
²The PCM pre-positions the idle air control (IAC)
motor.
²The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic fuel
strategy.
²The PCM monitors the engine coolant tempera-
ture sensor input. The PCM modifies fuel strategy
based on this input.
²Intake manifold air temperature sensor input is
monitored.
²Throttle position sensor (TPS) is monitored.
²The auto shutdown (ASD) relay is energized by
the PCM for approximately three seconds.
Fig. 7 DATA LINK CONNECTOR LOCATION
Fig. 8 PCM LOCATION
KJELECTRONIC CONTROL MODULES 8E - 11
DATA LINK CONNECTOR (Continued)

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)

LOAD TEST TEMPERATURE TABLE
Minimum VoltageTemperature
ÉF ÉC
9.6 volts 70É and above 21É and above
9.5 volts 60É 16É
9.4 volts 50É 10É
9.3 volts 40É 4É
9.1 volts 30É -1É
8.9 volts 20É -7É
8.7 volts 10É -12É
8.5 volts 0É -18É
(7) If the voltmeter reading falls below 9.6 volts, at
a minimum battery temperature of 21É C (70É F), the
battery is faulty and must be replaced.
STANDARD PROCEDURE - IGNITION-OFF
DRAW TEST
The term Ignition-Off Draw (IOD) identifies a nor-
mal condition where power is being drained from the
battery with the ignition switch in the Off position. A
normal vehicle electrical system will draw from five
to thirty-five milliamperes (0.005 to 0.035 ampere)
with the ignition switch in the Off position, and all
non-ignition controlled circuits in proper working
order. Up to thirty-five milliamperes are needed to
enable the memory functions for the Powertrain Con-trol Module (PCM), digital clock, electronically tuned
radio, and other modules which may vary with the
vehicle equipment.
A vehicle that has not been operated for approxi-
mately twenty days, may discharge the battery to an
inadequate level. When a vehicle will not be used for
twenty days or more (stored), remove the IOD fuse
from the Power Distribution Center (PDC). This will
reduce battery discharging.
Excessive IOD can be caused by:
²Electrical items left on.
²Faulty or improperly adjusted switches.
²Faulty or shorted electronic modules and compo-
nents.
²An internally shorted generator.
²Intermittent shorts in the wiring.
If the IOD is over thirty-five milliamperes, the
problem must be found and corrected before replac-
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes. See the Electronic Module Igni-
tion-Off Draw Table for more information.
ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
Radio No1to3
milliamperesN/A
Audio Power
AmplifierNoup to 1
milliampereN/A
Body Control Module
(BCM)No4.75
milliamperes
(max.)N/A
Powertrain Control
Module (PCM)No 0.95 milliampere N/A
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
Automatic
Transmission
Controller (EATX)Yes, 20 minutes 120 milliampere 0.70 ma
8F - 14 BATTERY SYSTEMKJ
BATTERY (Continued)

negative jumper posts. Select TESTING AT JUMPER
POST when connecting to that location.
(3) Connect the tester to the battery or jumper
posts, the red clamp to positive (+) and the black
clamp to negative (±).
NOTE: Multiple batteries connected in parallel must
have the ground cable disconnected to perform a
battery test. Failure to disconnect may result in
false battery test readings.
NOTE: When testing the battery in a PT Cruiser,
always test at the battery terminals
(4) Using the ARROW key selectinoroutof vehi-
cle testing and press ENTER to make a selection.
(5) If not selected, choose the Cold Cranking Amp
(CCA) battery rating. Or select the appropriate bat-
tery rating for your area (see menu). The tester will
then run its self programmed test of the battery and
display the results. Refer to the test result table
noted below.
CAUTION: If REPLACE BATTERY is the result of the
test, this may mean a poor connection between the
vehicle's cables and battery exists. After discon-
necting the vehicle's battery cables from the bat-
tery, retest the battery using the OUT-OF-VEHICLE
test before replacing.
(6) While viewing the battery test result, press the
CODE button and the tester will prompt you for the
last 4 digits of the VIN. Use the UP/DOWN arrow
buttons to scroll to the correct character; then press
ENTER to select and move to the next digit. Then
press the ENTER button to view the SERVICE
CODE. Pressing the CODE button a second time will
return you to the test results.
BATTERY TEST RESULTS
GOOD BATTERY Return to service
GOOD - RECHARGE Fully charge battery and
return to service
CHARGE & RETEST Fully charge battery and
retest battery
REPLACE BATTERY Replace the battery and
retest complete system
BAD-CELL REPLACE Replace the battery and
retest complete system
NOTE: The SERVICE CODE is required on every
warranty claim submitted for battery replacement.
REMOVAL
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post (Fig. 16).
(4) Loosen the battery positive cable terminal
clamp pinch-bolt hex nut.
(5) Disconnect the battery positive cable terminal
clamp from the battery positive terminal post. If nec-
essary, use a battery terminal puller to remove the
terminal clamp from the battery post.
(6) Remove the battery holddowns from the bat-
tery. Refer to Battery Holddown for the proper bat-
tery holddown removal procedures.
WARNING: WEAR A SUITABLE PAIR OF RUBBER
GLOVES (NOT THE HOUSEHOLD TYPE) WHEN
REMOVING A BATTERY BY HAND. SAFETY
GLASSES SHOULD ALSO BE WORN. IF THE BAT-
TERY IS CRACKED OR LEAKING, THE ELECTRO-
LYTE CAN BURN THE SKIN AND EYES.
(7) Remove the battery and the battery thermal
guard from the battery tray as a unit.
(8) Remove the battery thermal guard from the
battery case. Refer to Thermal Guard for the proper
battery thermal guard removal procedures.
INSTALLATION
(1) Clean and inspect all of the battery system
components. Refer to Battery System Cleaning for
the proper cleaning procedures, and refer to Battery
System Inspection for the proper inspection proce-
dures.
Fig. 16 Remove Battery Cable Terminal Clamp -
Typical
1 - BATTERY
2 - BATTERY TERMINAL PULLER
8F - 16 BATTERY SYSTEMKJ
BATTERY (Continued)