2002 JEEP LIBERTY Workshop Manual

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)

(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up to
three minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.
(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment in the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Power Distribution Center (PDC) and
then in the Junction Block (JB), one at a time until
the amperage reading becomes very low, or nonexist-
ent. Refer to the appropriate wiring information in
this service manual for complete PDC and JB fuse,
circuit breaker, and circuit identification. This will
isolate each circuit and identify the circuit that is the
source of the high-amperage IOD. If the amperage
reading remains high after removing and replacing
each fuse and circuit breaker, disconnect the wire
harness from the generator. If the amperage reading
now becomes very low or nonexistent, refer to Charg-
ing System for the proper charging system diagnosis
and testing procedures. After the high-amperage IOD
has been corrected, switch the multi-meter to pro-
gressively lower amperage scales and, if necessary,
repeat the fuse and circuit breaker remove-and-re-
place process to identify and correct all sources of
excessive IOD. It is now safe to select the lowest mil-
liampere scale of the multi-meter to check the low-
amperage IOD.
CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed thirty-five milliam-
peres (0.035 ampere). If the current draw exceeds
thirty-five milliamperes, isolate each circuit using the
fuse and circuit breaker remove-and-replace processin Step 5. The multi-meter reading will drop to
within the acceptable limit when the source of the
excessive current draw is disconnected. Repair this
circuit as required; whether a wiring short, incorrect
switch adjustment, or a component failure is at fault.
STANDARD PROCEDURE - USING
MIDTRONICS ELECTRICAL TESTER
Always use the Midtronics Instruction Manual that
was supplied with the tester as a reference. If the
Instruction Manual is not available the following pro-
cedure can be used:
WARNING: ALWAYS WEAR APPROPRIATE EYE
PROTECTION AND USE EXTREME CAUTION WHEN
WORKING WITH BATTERIES.
BATTERY TESTING
(1) If testing the battery OUT-OF-VEHICLE, clean
the battery terminals with a wire brush before test-
ing. If the battery is equipped with side post termi-
nals, install and tighten the supplied lead terminal
stud adapters. Do not use steel bolts. Failure to prop-
erly install the stud adapters, or using stud adapters
that are dirty or worn-out may result in false test
readings.
(2) If testing the battery IN-THE-VEHICLE, make
certain all of the vehicle accessory loads are OFF,
including the ignition.The preferred test position
is at the battery terminal. If the battery is not
accessible, you may test using both the positive and
Fig. 15 MIDTRONICS BATTERY AND CHARGING
SYSTEM TESTER - Micro420
KJBATTERY SYSTEM 8F - 15
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)

(2) Reinstall the battery thermal guard onto the
battery case. Refer to Thermal Guard for the proper
battery thermal guard installation procedures.
(3) Position the battery and the battery thermal
guard onto the battery tray as a unit. Ensure that
the battery positive and negative terminal posts are
correctly positioned. The battery cable terminal
clamps must reach the correct battery terminal post
without stretching the cables (Fig. 17).
(4) Reinstall the battery holddowns onto the bat-
tery. Refer to Battery Holddown for the proper instal-
lation procedure.
CAUTION: Be certain that the battery cable terminal
clamps are connected to the correct battery termi-
nal posts. Reversed battery polarity may damage
electrical components of the vehicle.
(5) Clean the battery cable terminal clamps and
the battery terminal posts. Refer to Battery System
Cleaning for cleaning procedure.
(6) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 45 in. lbs.
(7) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 45 in. lbs.
(8) Apply a thin coating of petroleum jelly or chas-
sis grease to the exposed surfaces of the battery cable
terminal clamps and the battery terminal posts.BATTERY HOLDDOWN
DESCRIPTION
The battery holddown hardware includes a plastic
holddown bracket and retaining bolt. The battery
holddown bracket meshes with the battery tray to
secure the battery to the battery tray.
When installing a battery into the battery tray, it
is important that the holddown hardware is properly
installed and that the fastener is tightened to the
proper specifications. Improper holddown fastener
tightness, whether too loose or too tight, can result in
damage to the battery, the vehicle, or both. Refer to
Battery Holddown for the proper installation proce-
dure, including the proper holddown fastener torque
specifications.
OPERATION
The battery holddown secures the battery in the
battery tray. This holddown is designed to prevent
battery movement during the most extreme vehicle
operation conditions. Periodic removal and lubrica-
tion of the battery holddown hardware is recom-
mended to prevent hardware seizure at a later date.
CAUTION: Never operate a vehicle without a battery
holddown device properly installed. Damage to the
vehicle, components and battery could result.
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.
(4) Remove the battery hold down bracket retain-
ing bolt from the threaded insert in the battery tray
assembly.
INSTALLATION
(1) Clean and inspect the battery hold down hard-
ware. Refer to Battery Cleaning for the proper bat-
tery system component cleaning procedures, and
Battery Inspection for the proper battery system
component inspection procedures.
(2) Position the battery hold down bracket onto the
battery tray.
Fig. 17 Battery Cables - Typical
1 - RADIATOR CROSSMEMBER
2 - WHEELHOUSE INNER PANEL
3 - NEGATIVE CABLE
4 - POSITIVE CABLE
5 - BATTERY
KJBATTERY SYSTEM 8F - 17
BATTERY (Continued)

(3) Install and tighten the battery hold down
bracket retaining bolt. Tighten the bolt to 4 N´m (20
in. lbs.).
(4) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 8.4 N´m (75
in. lbs.).
BATTERY CABLES
DESCRIPTION
The battery cables (Fig. 18) are large gauge,
stranded copper wires sheathed within a heavy plas-
tic or synthetic rubber insulating jacket. The wire
used in the battery cables combines excellent flexibil-
ity and reliability with high electrical current carry-
ing capacity. The battery cables feature a clamping
type female battery terminal made of soft lead that is
die cast onto one end of the battery cable wire. A
square headed pinch-bolt and hex nut are installed
at the open end of the female battery terminal clamp.
Large eyelet type terminals are crimped onto the
opposite end of the battery cable wire and then sol-
der-dipped. The battery positive cable wires have a
red insulating jacket to provide visual identificationand feature a larger female battery terminal clamp
to allow connection to the larger battery positive ter-
minal post. The battery negative cable wires have a
black insulating jacket and a smaller female battery
terminal clamp.
The battery cables cannot be repaired and, if dam-
aged or faulty they must be replaced. Both the bat-
tery positive and negative cables are available for
service replacement only as a unit with the battery
wire harness, which may include portions of the wir-
ing circuits for the generator and other components
on some models. Refer to the appropriate wiring
information in this service manual for the location of
the proper battery cable wire harness diagrams. The
wiring information also includes proper wire and con-
nector repair procedures, further details on wire har-
ness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
OPERATION
The battery cables connect the battery terminal
posts to the vehicle electrical system. These cables
also provide a path back to the battery for electrical
current generated by the charging system for restor-
ing the voltage potential of the battery. The female
battery terminal clamps on the ends of the battery
cable wires provide a strong and reliable connection
of the battery cable to the battery terminal posts.
The terminal pinch bolts allow the female terminal
clamps to be tightened around the male terminal
posts on the top of the battery. The eyelet terminals
secured to the opposite ends of the battery cable
wires from the female battery terminal clamps pro-
vide secure and reliable connection of the battery
cables to the vehicle electrical system.
The battery positive cable terminal clamp is die
cast onto the ends of two wires. One wire has an eye-
let terminal that connects the battery positive cable
to the B(+) terminal studs of the Power Distribution
Center (PDC), and the other wire has an eyelet ter-
minal that connects the battery positive cable to the
B(+) terminal stud of the engine starter motor sole-
noid. The battery negative cable terminal clamp is
also die cast onto the ends of two wires. One wire
has an eyelet terminal that connects the battery neg-
ative cable to the vehicle powertrain through a stud
on the left side of the engine cylinder block. The
other wire has an eyelet terminal that connects the
battery negative cable to the vehicle body through a
ground stud on the left wheel house, near the bat-
tery.
Fig. 18 Battery Cables - Typical
1 - Battery
2 - Radiator Crossmember
3 - Terminal Clamps
4 - Fender Inner Shield
5 - Negative Cable
6 - Positive Cable
8F - 18 BATTERY SYSTEMKJ
BATTERY HOLDDOWN (Continued)

DIAGNOSIS AND TESTING - BATTERY CABLES
A voltage drop test will determine if there is exces-
sive resistance in the battery cable terminal connec-
tions or the battery cable. If excessive resistance is
found in the battery cable connections, the connec-
tion point should be disassembled, cleaned of all cor-
rosion or foreign material, then reassembled.
Following reassembly, check the voltage drop for the
battery cable connection and the battery cable again
to confirm repair.
When performing the voltage drop test, it is impor-
tant to remember that the voltage drop is giving an
indication of the resistance between the two points at
which the voltmeter probes are attached.EXAM-
PLE:When testing the resistance of the battery pos-
itive cable, touch the voltmeter leads to the battery
positive cable terminal clamp and to the battery pos-
itive cable eyelet terminal at the starter solenoid
B(+) terminal stud. If you probe the battery positive
terminal post and the battery positive cable eyelet
terminal at the starter solenoid B(+) terminal stud,
you are reading the combined voltage drop in the
battery positive cable terminal clamp-to-terminal
post connection and the battery positive cable.
VOLTAGE DROP TEST
The following operation will require a voltmeter
accurate to 1/10 (0.10) volt. Before performing this
test, be certain that the following procedures are
accomplished:
²The battery is fully-charged and load tested.
Refer to Standard Procedures for the proper battery
charging and load test procedures.
²Fully engage the parking brake.
²If the vehicle is equipped with an automatic
transmission, place the gearshift selector lever in the
Park position. If the vehicle is equipped with a man-
ual transmission, place the gearshift selector lever in
the Neutral position and block the clutch pedal in the
fully depressed position.
²Verify that all lamps and accessories are turned
off.
²To prevent the engine from starting, remove the
Automatic Shut Down (ASD) relay. The ASD relay is
located in the Power Distribution Center (PDC), in
the engine compartment. See the fuse and relay lay-
out label affixed to the underside of the PDC cover
for ASD relay identification and location.
(1) Connect the positive lead of the voltmeter to
the battery negative terminal post. Connect the neg-
ative lead of the voltmeter to the battery negative
cable terminal clamp (Fig. 19). Rotate and hold the
ignition switch in the Start position. Observe the
voltmeter. If voltage is detected, correct the poor con-
nection between the battery negative cable terminal
clamp and the battery negative terminal post.(2) Connect the positive lead of the voltmeter to
the battery positive terminal post. Connect the nega-
tive lead of the voltmeter to the battery positive cable
terminal clamp (Fig. 20). Rotate and hold the ignition
switch in the Start position. Observe the voltmeter. If
voltage is detected, correct the poor connection
between the battery positive cable terminal clamp
and the battery positive terminal post.
(3) Connect the voltmeter to measure between the
battery positive cable terminal clamp and the starter
solenoid B(+) terminal stud (Fig. 21). Rotate and hold
the ignition switch in the Start position. Observe the
voltmeter. If the reading is above 0.2 volt, clean and
tighten the battery positive cable eyelet terminal con-
Fig. 19 TEST BATTERY NEGATIVE CONNECTION
RESISTANCE - TYPICAL
1 - VOLTMETER
2 - BATTERY
Fig. 20 TEST BATTERY POSITIVE CONNECTION
RESISTANCE - TYPICAL
1 - VOLTMETER
2 - BATTERY
KJBATTERY SYSTEM 8F - 19
BATTERY CABLES (Continued)

nection at the starter solenoid B(+) terminal stud.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery positive cable.
(4) Connect the voltmeter to measure between the
battery negative cable terminal clamp and a good
clean ground on the engine block (Fig. 22). Rotate
and hold the ignition switch in the Start position.
Observe the voltmeter. If the reading is above 0.2
volt, clean and tighten the battery negative cable
eyelet terminal connection to the engine block.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery negative cable.THERMAL GUARD
DESCRIPTION
A flexible plastic bubble-wrap style thermal guard
(Fig. 23) slides over the battery case to enclose the
sides of the battery. The thermal guard consists of a
heavy black plastic outer skin and two lighter plies of
plastic that have been formed into a sheet with hun-
dreds of small air pockets entrapped between them.
The resulting material is very similar to the bubble-
wrap used to protect items in many parcel packaging
and shipping applications.
OPERATION
The thermal guard protects the battery from
engine compartment temperature extremes. The tem-
perature of the battery can affect battery perfor-
mance. The air trapped between the plastic plies of
the thermal guard create a dead air space, which
helps to insulate the sides of the battery case from
the air temperature found in the surrounding engine
compartment.
REMOVAL
(1) Remove the battery and the battery thermal
guard from the battery tray as a unit. Refer to Bat-
tery Removal for the proper battery removal proce-
dures.
(2) Carefully and evenly slide the battery thermal
guard up off of the battery case (Fig. 24).
INSTALLATION
(1) Clean and inspect the battery thermal guard.
Refer to Battery System Cleaning for the proper
cleaning procedures, and refer to Battery System
Inspection for the proper inspection procedures.
Fig. 21 TEST BATTERY POSITIVE CABLE
RESISTANCE - TYPICAL
1 - BATTERY
2 - VOLTMETER
3 - STARTER MOTOR
Fig. 22 TEST GROUND CIRCUIT RESISTANCE -
TYPICAL
1 - VOLTMETER
2 - BATTERY
3 - ENGINE GROUND
Fig. 23 Battery Thermal guard
1 - THERMAL GUARD
2 - BATTERY
8F - 20 BATTERY SYSTEMKJ
BATTERY CABLES (Continued)

(2) Carefully and evenly slide the battery thermal
guard down over the battery case.
(3) Install the battery and the battery thermal
guard into the battery tray as a unit. Refer to Bat-
tery Installation for the proper battery installation
procedures.
BATTERY TRAY
DESCRIPTION
The battery is placed in a molded plastic tray
located in the left front corner of the engine compart-
ment (Fig. 25). The battery hold down hardware is
contained within the battery tray. A hole in the bot-
tom of the battery tray is fitted with a battery tem-
perature sensor. Refer to Charging System for more
information on the battery temperature sensor. Refer
to Battery Hold down for more information on hold
down hardware.
OPERATION
The battery tray provides a secure mounting loca-
tion and supports the battery. On some vehicles, the
battery tray also provides the anchor point/s for the
battery holddown hardware. The battery tray and
the battery holddown hardware combine to secure
and stabilize the battery in the engine compartment,
which prevents battery movement during vehicle
operation. Unrestrained battery movement during
vehicle operation could result in damage to the vehi-
cle, the battery, or both.
REMOVAL
(1) Remove the battery from the battery tray
(Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BAT-
TERY - REMOVAL).
(2) Unlatch and remove the PDC from the battery
tray.
(3) Remove the battery temperature sensor from
the battery tray (Refer to 8 - ELECTRICAL/CHARG-
ING/BATTERY TEMPERATURE SENSOR -
REMOVAL).
(4) Remove the three nuts that secure the battery
tray to the weld studs on the front extension of the
left front wheelhouse inner panel (Fig. 25).
(5) Remove the battery tray from the vehicle.
INSTALLATION
(1) Clean and inspect the battery tray (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM - CLEANING).
(2) Position the battery tray onto the weld studs
on the front extension of the left front wheelhouse
inner panel.
(3) Install the battery temperature sensor onto the
battery tray (Refer to 8 - ELECTRICAL/CHARGING/
BATTERY TEMPERATURE SENSOR - INSTALLA-
TION).
(4) Install and tighten the three nuts that secure
the battery tray to the weld studs on the front exten-
sion of the left front wheelhouse inner panel. Tighten
the nuts to 5 N´m (45 in. lbs.).
(5) Install the PDC on the battery tray.
(6) Install the battery onto the battery tray (Refer
to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY -
INSTALLATION).
Fig. 24 Battery thermal guard
1 - THERMAL GUARD
2 - BATTERY
Fig. 25 Battery Tray Location
1 - Battery Tray
2 - Battery Tray Retaining Nuts
KJBATTERY SYSTEM 8F - 21
THERMAL GUARD (Continued)