2002 JEEP LIBERTY Page 21

CONDITION POSSIBLE CAUSES CORRECTION
BELT SLIPS 1. Belt slipping because of
insufficient tension.1. Replace automatic belt tensioner.
2. Belt routed 2. Verify belt routing.
incorrectly
3. Incorrect belt. 3. Replace belt.
4. Belt or pulley subjected to
substance (belt dressing, oil
ethylene glycol) that has reduced
friction.4. Replace belt and clean pulleys.
5. Driven component bearing failure. 5. Replace faulty component
bearing.
6. Belt glazed and hardened from
heat and excessive slippage.6. Replace belt.
ªGROOVE JUMPING9(BELT
DOES NOT MAINTAIN CORRECT
POSITION ON PULLEY)1. Belt tension either too high or too
low.1. Replace automatic belt tensioner.
2. Belt routed 2. Verify belt routing.
incorrectly.
3. Incorrect belt. 3. Replace belt.
4. Pulley(s) not within design
tolerance.4. Replace pulley(s).
5. Foreign object(s) in grooves. 5. Remove foreign objects from
grooves.
6. Pulley misalignment. 6. Check and replace.
7. Belt cord line is broken. 7. Replace belt.
BELT BROKEN (NOTE: IDENTIFY
AND CORRECT PROBLEM
BEFORE NEW BELT IS
INSTALLED)1. Excessive tension. 1. Replace belt and automatic belt
tensioner.
2. Incorrect belt. 2. Replace belt.
3. Tensile member damaged during
belt installation.3. Replace belt.
4. Severe misalignment. 4. Check and replace.
5. Bracket, pulley, or bearing failure. 5. Replace defective component and
belt.
NOISE (OBJECTIONABLE
SQUEAL, SQUEAK, OR RUMBLE
IS HEARD OR FELT WHILE
DRIVE BELT IS IN OPERATION)1. Belt slippage. 1. Replace belt or automatic belt
tensioner.
2. Bearing noise. 2. Locate and repair.
3. Belt misalignment. 3. Replace belt.
4. Belt-to-pulley mismatch. 4. Install correct belt.
REMOVAL - 2.4L ENGINE
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label. This label is located
in the engine compartment.CAUTION: DO NOT LET TENSIONER ARM SNAP
BACK TO THE FREEARM POSITION, SEVERE DAM-
AGE MAY OCCUR TO THE TENSIONER.
Belt tension is not adjustable. Belt adjustment is
maintained by an automatic ( spring load ) belt ten-
sioner.
(1) Disconnect negative battery cable from battery.
(2) Rotate belt tensioner until it contacts its stop.
Remove belt, then slowly rotate the tensioner into
the freearm position.
7s - 16 ACCESSORY DRIVEKJ
DRIVE BELTS -2.4L (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION
DESCRIPTION - HOAT COOLANT.........18
DESCRIPTION - ENGINE COOLANT.......19
OPERATION...........................20
COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION.........................20
OPERATION...........................20
ENGINE BLOCK HEATER - 2.4L
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL - 2.4L........................20
INSTALLATION - 2.4L....................20
ENGINE COOLANT TEMPERATURE SENSOR
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................22
ENGINE COOLANT THERMOSTAT
REMOVAL - 2.4L ENGINE.................22
INSTALLATION - 2.4L ENGINE.............22
RADIATOR
DESCRIPTION.........................22REMOVAL.............................22
CLEANING............................24
INSPECTION..........................24
INSTALLATION.........................24
RADIATOR PRESSURE CAP
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP......................25
CLEANING............................25
INSPECTION..........................25
RADIATOR FAN - ELECTRIC
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
INSTALLATION.........................27
WATER PUMP - 2.4L
DESCRIPTION.........................27
OPERATION...........................27
REMOVAL - 2.4L ENGINE.................27
INSPECTION..........................28
INSTALLATION - 2.4L ENGINE.............28
COOLANT
DESCRIPTION
DESCRIPTION - HOAT COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHENENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5 Year/100,000
Mile Formula (MS-9769), or the equivalent ethylene
glycol base coolant with organic corrosion inhibitors
(called HOAT, for Hybrid Organic Additive Technology)
is recommended. This coolant offers the best engine
cooling without corrosion when mixed with 50% Eth-
ylene Glycol and 50% distilled water to obtain a freeze
point of -37ÉC (-35ÉF). If it loses color or becomes con-
taminated, drain, flush, and replace with fresh prop-
erly mixed coolant solution.
7s - 18 ENGINEKJ

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

AUDIO
TABLE OF CONTENTS
page page
AUDIO
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - AUDIO..........2
AMPLIFIER CHOKE AND RELAY
DESCRIPTION..........................3
OPERATION............................3
DIAGNOSIS AND TESTING - AMPLIFIER
CHOKE AND RELAY....................4
REMOVAL.............................4
INSTALLATION..........................4
ANTENNA BODY & CABLE
DESCRIPTION..........................4
OPERATION............................5
DIAGNOSIS AND TESTING - ANTENNA BODY
AND CABLE..........................5
REMOVAL.............................6
INSTALLATION..........................6
CD CHANGER
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................7
INSTALLATION..........................7
INSTRUMENT PANEL ANTENNA CABLE
REMOVAL.............................7INSTALLATION..........................8
RADIO
DESCRIPTION..........................8
OPERATION............................8
REMOVAL.............................9
INSTALLATION..........................9
RADIO NOISE SUPPRESSION GROUND STRAP
DESCRIPTION..........................9
OPERATION...........................10
REMOVAL.............................10
INSTALLATION.........................11
REMOTE SWITCHES
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - REMOTE
SWITCHES..........................12
REMOVAL.............................13
INSTALLATION.........................13
SPEAKER
DESCRIPTION.........................13
OPERATION...........................14
REMOVAL.............................14
INSTALLATION.........................15
AUDIO
DESCRIPTION
An audio system is standard factory-installed
equipment on this model. Several combinations of
radio receivers and speaker systems are offered on
this model. The audio system uses an ignition
switched source of battery current so that the system
will only operate when the ignition switch is in the
RUN or ACCESSORY positions.
The audio system includes the following compo-
nents:
²Amplifier choke and relay
²Antenna
²Compact disc changer (if equipped)
²Power amplifier mounted to each front door
speaker (with premium speaker system only)
²Radio noise suppression components
²Radio receiver
²Remote radio switches (if equipped)
²SpeakersCertain functions and features of the audio system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munication Interface (PCI) bus network. The data
bus network allows the sharing of sensor informa-
tion. For diagnosis of these electronic modules or of
the data bus network, the use of a DRB scan tool and
the proper Diagnostic Procedures manual are recom-
mended.
Refer to the appropriate wiring information for
complete standard and premium audio system circuit
diagrams. The wiring information includes 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.
OPERATION
The audio system components are designed to pro-
vide audio entertainment and information through
the reception, tuning and amplification of locally
broadcast radio signals in both the Amplitude Modu-
KJAUDIO 8A - 1

CHIME/BUZZER
TABLE OF CONTENTS
page page
CHIME WARNING SYSTEM
DESCRIPTION..........................1
OPERATION............................2DIAGNOSIS AND TESTING - CHIME
WARNING SYSTEM.....................6
CHIME WARNING SYSTEM
DESCRIPTION
Fig. 1 Chime Warning System
1 - ELECTROMECHANICAL INSTRUMENT CLUSTER
KJCHIME/BUZZER 8B - 1

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

NOTE: If three attempts are made to enter secured
access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To
exit this lockout mode, turn the ignition switch to
the ON position for one hour, then enter the correct
PIN. (Ensure all accessories are turned off. Also
monitor the battery state and connect a battery
charger if necessary).
(6) Press ENTER to transfer the secret key (the
SKIM will send the secret key to the PCM).
(7) Press PAGE BACK to get to the Select System
menu and select ENGINE, MISCELLANEOUS, and
SRI MEMORY CHECK.
(8) The DRBIIItwill ask, ªIs odometer reading
between XX and XX?º Select the YES or NO button
on the DRBIIIt. If NO is selected, the DRBIIItwill
read, ªEnter Odometer Reading (From I.P. odome-
ter)º. Enter the odometer reading from the instru-
ment cluster and press ENTER.
PROGRAMMING THE SKIM
(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) Program the vehicle four-digit PIN into SKIM.
(5) Select COUNTRY CODE and enter the correct
country.
NOTE: Be sure to enter the correct country code. If
the incorrect country code is programmed into
SKIM, it cannot be changed and the SKIM must be
replaced.
(6) Select YES to update VIN (the SKIM will learn
the VIN from the PCM).
(7) Press ENTER to transfer the secret key (the
PCM will send the secret key to the SKIM).
(8) Program ignition keys to the SKIM.
NOTE: If the PCM and the SKIM are replaced at the
same time, all vehicle ignition keys will need to be
replaced and programmed to the new SKIM.
PROGRAMMING IGNITION KEYS TO THE SKIM
(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 PROGRAM IGNITION KEY'S.
(4) Enter secured access mode by entering the
vehicle four-digit PIN.NOTE: A maximum of eight keys can be learned to
each SKIM. Once a key is learned to a SKIM it (the
key) cannot be transferred to another vehicle.
(5) Obtain ignition keys to be programmed from
the customer (8 keys maximum).
(6) Using the DRBIIIt, erase all ignition keys by
selecting MISCELLANEOUS, and ERASE ALL CUR-
RENT IGN. KEYS.
(7) Program all of the ignition keys.
If ignition key programming is unsuccessful, the
DRBIIItwill display one of the following messages:
²Programming Not Attempted- The DRBIIIt
attempts to read the programmed key status and
there are no keys programmed into SKIM memory.
²Programming Key Failed (Possible Used
Key From Wrong Vehicle)- SKIM is unable to pro-
gram an ignition key transponder due to one of the
following:
²The ignition key transponder is faulty.
²The ignition key transponder is or has been
already programmed to another vehicle.
²8 Keys Already Learned, Programming Not
Done- The SKIM transponder ID memory is full.
²Learned Key In Ignition- The ID for the igni-
tion key transponder currently in the ignition lock
cylinder is already programmed in SKIM memory.
BODY CONTROL MODULE
DESCRIPTION
A Body Control Module (BCM) is concealed behind
the driver side end of the instrument panel in the
passenger compartment, where it is secured to the
fuse panel side of the Junction Block (JB) with four
screws (Fig. 1). The JB is the interface between the
body, the instrument panel, and the headlamp and
dash wire harnesses. The JB also contains the fuses
and relays used for the interior electrical system of
the vehicle. The BCM is enclosed in a molded plastic
housing with two integral external connector recepta-
cles that connect it to the vehicle electrical system
through two take outs with connectors from the
instrument panel wire harness (Fig. 2). The BCM
also has an integral interface connector concealed on
the back side of the unit that joins it through a con-
nector receptacle that is integral to the JB housing to
the circuitry within the JB. This connector is referred
to as the JB-BCM connector. The combined BCM and
JB are sometimes referred to as the Junction Block
Module (JBM).
8E - 2 ELECTRONIC CONTROL MODULESKJ
ELECTRONIC CONTROL MODULES (Continued)

ENGINE SYSTEMS
TABLE OF CONTENTS
page page
BATTERY SYSTEM......................... 1
CHARGING SYSTEM....................... 22STARTING SYSTEM....................... 32
BATTERY SYSTEM
TABLE OF CONTENTS
page page
BATTERY SYSTEM
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING - BATTERY
SYSTEM.............................2
CLEANING.............................5
INSPECTION...........................6
SPECIFICATIONS........................6
SPECIAL TOOLS........................7
BATTERY
DESCRIPTION..........................7
DIAGNOSIS AND TESTING - BATTERY.......8
STANDARD PROCEDURE
STANDARD PROCEDURE - BATTERY
CHARGING...........................8
STANDARD PROCEDURE - BUILT-IN
INDICATOR TEST.....................10
STANDARD PROCEDURE - HYDROMETER
TEST...............................11
STANDARD PROCEDURE - OPEN-CIRCUIT
VOLTAGE TEST.......................12
STANDARD PROCEDURE - LOAD TEST....12
STANDARD PROCEDURE - IGNITION-OFF
DRAW TEST.........................14STANDARD PROCEDURE - USING
MIDTRONICS ELECTRICAL TESTER.......15
REMOVAL.............................16
INSTALLATION.........................16
BATTERY HOLDDOWN
DESCRIPTION.........................17
OPERATION...........................17
REMOVAL.............................17
INSTALLATION.........................17
BATTERY CABLES
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - BATTERY
CABLES............................19
THERMAL GUARD
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................20
BATTERY TRAY
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................21
BATTERY SYSTEM
DESCRIPTION
A single 12-volt battery system is standard factory-
installed equipment on this model. All of the compo-
nents of the battery system are located within the
engine compartment of the vehicle. The service infor-
mation for the battery system in this vehicle covers
the following related components, which are covered
in further detail elsewhere in this service manual:²Battery- The storage battery provides a reli-
able means of storing a renewable source of electrical
energy within the vehicle.
²Battery Cable- The battery cables connect the
battery terminal posts to the vehicle electrical sys-
tem.
²Battery Holddown- The battery holddown
hardware secures the battery in the battery tray in
the engine compartment.
KJENGINE SYSTEMS 8F - 1