2002 JEEP LIBERTY electric

Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
OPERATION
Coolant flows through the engine block absorbing
the heat from the engine, then flows to the radiator
where the cooling fins in the radiator transfers the
heat from the coolant to the atmosphere. During cold
weather the ethylene-glycol coolant prevents water
present in the cooling system from freezing within
temperatures indicated by mixture ratio of coolant to
water.
COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/ad-
justing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover
minor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
The coolant reservoir/overflow system has a radia-
tor mounted pressurized cap, an overflow tube, and a
plastic coolant reservoir/overflow tank, mounted to
the right side of the cowl. It is mounted to the cowl
with two nuts on top, and a slide bracket on the bot-
tom.
OPERATION
The pressure chamber keeps the coolant free of
trapped air, provides a volume for expansion and con-
traction, and provides a convenient and safe method
for checking and adjusting coolant level at atmo-
spheric pressure. It also provides some reserve cool-
ant to cover minor leaks, evaporation or boiling
losses. The overflow chamber allows coolant recovery
in case of an overheat.
ENGINE BLOCK HEATER - 2.4L
DESCRIPTION
The block heater is operated by ordinary house
current (110 Volt A.C.) through a power cord and con-
nector located in the engine compartment. The
heater is mounted in a core hole (in place of a core
hole plug) in the engine block, with the heating ele-
ment immersed in coolant.
CAUTION: The power cord must be secured in its
retainer clips, and not positioned so it could con-
tact linkages or exhaust manifolds and become
damaged.
OPERATION
The block heater element is submerged in the cool-
ing system's coolant. When electrical power (110 volt
A.C.) is applied to the element, it creates heat. This
heat is transferred to the engine coolant. This pro-
vides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures.
REMOVAL - 2.4L
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE - STANDARD PROCEDURE).
(2) Raise vehicle on hoist.
(3) Detach power cord plug from heater.
(4) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION - 2.4L
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly (Fig. 1) with element
loop positionedupward.
(3) With heater seated, tighten center screw
securely to assure a positive seal.
CAUTION: To prevent damage, the power cord must
be secured in it's retaining clips, and not positioned
so it could contact linkages or exhaust manifold.
(4) Connect power cord to heater.
(5) Lower vehicle.
(6) Fill cooling system (Refer to 7 - COOLING/EN-
GINE - STANDARD PROCEDURE).
7s - 20 ENGINEKJ
COOLANT (Continued)

ENGINE COOLANT
TEMPERATURE SENSOR
DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is
used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.
The ECT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as engine coolant
temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
At key-on, the Powertrain Control Module (PCM)
sends out a regulated 5 volt signal to the ECT sensor.
The PCM then monitors the signal as it passes
through the ECT sensor to the sensor ground (sensor
return).
When the engine is cold, the PCM will operate in
Open Loop cycle. It will demand slightly richer air-
fuel mixtures and higher idle speeds. This is done
until normal operating temperatures are reached.
The PCM uses inputs from the ECT sensor for the
following calculations:
²for engine coolant temperature gauge operation
through CCD or PCI (J1850) communications
²Injector pulse-width²Spark-advance curves
²ASD relay shut-down times
²Idle Air Control (IAC) motor key-on steps
²Pulse-width prime-shot during cranking
²O2 sensor closed loop times
²Purge solenoid on/off times
²EGR solenoid on/off times (if equipped)
²Leak Detection Pump operation (if equipped)
²Radiator fan relay on/off times (if equipped)
²Target idle speed
REMOVAL
2.4L
The Engine Coolant Temperature (ECT) sensor is
installed into a water jacket at left front of cylinder
head (Fig. 2).
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Partially drain cooling system.
(2) Disconnect electrical connector from sensor.
(3) Remove sensor from cylinder head.
3.7L
The Engine Coolant Temperature (ECT) sensor is
installed into a water jacket at front of intake mani-
fold near rear of generator (Fig. 3).
Fig. 1 ENGINE BLOCK HEATER 2.4L
1 - CORE HOLE
2 - BLOCK HEATER
3 - POWER CORD
Fig. 2 ECT AND UPPER TIMING BELT COVER/
BOLTS-2.4L
1 - UPPER TIMING BELT COVER
2 - ELECTRICAL CONNECTOR (ECT)
3 - MOUNTING BOLTS (3)
KJENGINE7s-21
ENGINE BLOCK HEATER - 2.4L (Continued)

WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Partially drain cooling system.
(2) Disconnect electrical connector from sensor.
(3) Remove sensor from intake manifold.
INSTALLATION
(1) Apply thread sealant to sensor threads.
(2) Install sensor to engine.
(3) Tighten sensor to 11 N´m (8 ft. lbs.) torque.
(4) Replace any lost engine coolant.
ENGINE COOLANT
THERMOSTAT
REMOVAL - 2.4L ENGINE
(1) Drain cooling system below the thermostat
level.
(2) Remove radiator upper hose from the coolant
outlet housing.
(3) Remove coolant outlet housing bolts and hous-
ing.
(4) Remove thermostat. Discard gasket and clean
both gasket sealing surfaces.
INSTALLATION - 2.4L ENGINE
(1) Place a new gasket (dipped in clean water) on
the coolant outlet connector surface. Position thermo-
stat with air bleed at the 12 o'clock position in ther-
mostat housing.
(2) Position the coolant outlet connector and gas-
ket over the thermostat, making sure thermostat is
seated in the thermostat housing.
(3) Position outlet connector to thermostat housing
and install bolts. Tighten bolts to 28 N´m (250 in.
lbs.).
(4) Install the radiator upper hose to coolant outlet
housing.
(5) Refill the cooling system.
RADIATOR
DESCRIPTION
All vehicles are equipped with a cross flow type
radiator with plastic side tanks (Fig. 4).
Plastic tanks, while stronger than brass, are sub-
ject to damage by impact, such as from tools or
wrenches. Handle radiator with care.
REMOVAL
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR. REFER TO COOLING SYSTEM DRAIN-
ING.
Fig. 3 MAP SENSOR / ECT SENSOR - 3.7L
1 - MOUNTING SCREWS
2 - MAP SENSOR
3 - ECT SENSOR
Fig. 4 Cross Flow Radiator - Typical
1 - RADIATOR
7s - 22 ENGINEKJ
ENGINE COOLANT TEMPERATURE SENSOR (Continued)

Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 5). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 6). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
CAUTION: When removing the radiator or A/C con-
denser for any reason, note the location of all radi-
ator-to-body and radiator-to-A/C condenser rubber
air seals (Fig. 7). These are used at the top, bottom
and sides of the radiator and A/C condenser. To
prevent overheating, these seals must be installed
to their original positions.
(1) Disconnect the negative battery cable at bat-
tery.
(2) Drain coolant from radiator (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(3) Remove the front grill (Refer to 23 - BODY/EX-
TERIOR/GRILLE - REMOVAL).
(4) Remove the cooling fan from the engine, if
equipped.
(5) Remove the two radiator mounting bolts.(6) Disconnect both transmission cooler lines from
radiator.
(7) Disconnect the connector for the electric fan.
Fig. 5 Hose Clamp Tool - Typical
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 6 Clamp Number/Letter Location - Typical
1 - TYPICAL CONSTANT TENSION HOSE CLAMP
2 - CLAMP NUMBER/LETTER LOCATION
3 - TYPICAL HOSE
Fig. 7 Air Seals - Typical
1 - AIR DAM
2 - RADIATOR
3 - AIR DAM
4 - A/C CONDENSER
5 - AIR SEAL
KJENGINE7s-23
RADIATOR (Continued)

(8) Disconnect the power steering cooler line from
cooler.
(9) Disconnect the radiator upper and lower hoses.
(10) Disconnect the overflow hose from radiator.
(11) The lower part of radiator is equipped with
two alignment dowel pins (Fig. 8). They are located
on the bottom of radiator tank and fit into rubber
grommets. These rubber grommets are pressed into
the radiator lower crossmember.
WARNING: THE AIR CONDITIONING SYSTEM (IF
EQUIPPED) IS UNDER A CONSTANT PRESSURE
EVEN WITH THE ENGINE OFF. REFER TO REFRIG-
ERANT WARNINGS IN, HEATING AND AIR CONDI-
TIONING BEFORE HANDLING ANY AIR
CONDITIONING COMPONENT.
NOTE: The radiator and radiator cooling fan can be
removed as an assembly. It is not necessary to
remove the cooling fan before removing or install-
ing the radiator.
(12) Gently lift up and remove radiator from vehi-
cle. Be careful not to scrape the radiator fins against
any other component. Also be careful not to disturb
the air conditioning condenser (if equipped).CLEANING
Clean radiator fins With the engine cold, apply cold
water and compressed air to the back (engine side) of
the radiator to flush the radiator and/or A/C con-
denser of debris.
INSPECTION
The radiator cooling fins should be checked for
damage or deterioration. Inspect cooling fins to make
sure they are not bent or crushed, these areas result
in reduced heat exchange causing the cooling system
to operate at higher temperatures. Inspect the plastic
end tanks for cracks, damage or leaks.
Inspect the radiator neck for damage or distortion.
INSTALLATION
CAUTION: Before installing the radiator or A/C con-
denser, be sure the radiator-to-body and radiator-to-
A/C condenser rubber air seals are properly
fastened to their original positions. These are used
at the top, bottom and sides of the radiator and A/C
condenser. To prevent overheating, these seals
must be installed to their original positions.
(1) Gently lower the radiator and fan shroud into
the vehicle. Guide the two radiator alignment dowels
into the rubber grommets located in lower radiator
crossmember.
(2) Connect the radiator upper and lower hoses
and hose clamps to radiator.
CAUTION: The tangs on the hose clamps must be
positioned straight down.
(3) Install coolant reserve/overflow tank hose at
radiator.
(4) Connect both transmission cooler lines at the
radiator.
(5) Install both radiator mounting bolts.
(6) Reconnect the electric cooling fan.
(7) Install the grill (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION).
(8) Reinstall the cooling fan to the engine.
(9) Rotate the fan blades (by hand) and check for
interference at fan shroud.
(10) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Connect battery cable at battery.
(12) Start and warm engine. Check for leaks.
Fig. 8 Radiator Alignment Dowels - Typical
1 - RADIATOR
2 - ALIGNMENT DOWEL
3 - RADIATOR LOWER ISOLATOR
4 - RADIATOR LOWER CROSSMEMBER
7s - 24 ENGINEKJ
RADIATOR (Continued)

RADIATOR FAN - ELECTRIC
DESCRIPTION
The fan (Fig. 11) is electrically controlled by the
powertrain control module (PCM) through the fan
control relay. This relay is located on the left wheel
house in the engine compartment.
OPERATION
The electric radiator cooling fan is controlled by
the Powertrain Control Module (PCM) through the
radiator cooling fan relay. The PCM regulates fan
operation based on input from the engine coolant
temperature sensor, battery temperature sensor,air
conditioning select switch and vehicle speed.
The fan is not energized during engine cranking
regardless of the electrical input from the tempera-
ture sensors and ,air conditioning switch. However, if
engine operation conditions warrant fan engagement,
the fan will run once engine starts.
On vehicles NOT equipped with AC:The relay
is energized when the coolant temperature is above
80É C (176É F), or battery temperature sensor above ±
12É C (10É F). It will then de-energize when coolant
temperature drops below 82É C (180É F), or batter
temperature sensor below ± 9É C ( 16É F).
Vehicles Equipped with AC:In addition to using
coolant temperature and battery temperature sensorto control cooling fan operation, the cooling fan will
also be engaged when the ,air conditioning system is
activated. The relay is also energized when, air con-
ditioning is selected and coolant temperature is
above 95É C ( 203É F), or , air conditioning is selected
and battery temperature sensor is above 41É C (106É
F). It will then de-energize when , air conditioning is
selected and coolant temperature is below 92É C
(198É F), or , air conditioning is selected and battery
temperature is below 38É C (100É F).
REMOVAL
If the fan blade is bent, warped, cracked or dam-
aged in any way, it must be replacedonlywith a
replacement fan blade.Do not attempt to repair a
damaged fan blade.
NOTE: For 3.7L Heavy Duty/Max Cool/Trailer Tow
cooling package, the viscous fan cannot be
removed seperate from the shroud. Both fan and
shroud must be removed together.
(1) Disconnect battery negative cable.
(2) Using special tool 6958 spanner wrench and
8346 adapters, remove the viscous fan from the
water pump (Fig. 12).
(3) Gently lay fan into shroud.
(4) Disconnect the electrical connector for the elec-
tric fan, then disconnect connector from shroud.
Fig. 11 Radiator Cooling Fan - Typical
1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN
Fig. 12 Viscous Fan and Fan Drive 3.7L
1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2-FAN
7s - 26 ENGINEKJ

(5) Remove the two fan shroud mounting bolts con-
necting the fan shroud to the radiator (Fig. 13).
(6) Remove the shroud and fan from the vehicle.
INSTALLATION
NOTE: For 3.7L Heavy Duty/Max Cool/Trailer Tow
cooling package, the viscous fan cannot be
installed seperate from the shroud. Both fan and
shroud must be installed together.
(1) Gently lay viscous fan into shroud.
(2) Install fan shroud assembly into the vehicle.
Tighten fan shroud to radiator bolts to (5.5 N´m (50
in. lbs.).
(3) Using special tool 6958 spanner wrench and
8346 adapters, install the viscous fan on the water
pump.
(4) Connect fan motor wire connector to harness
connector, and attach connector to shroud.
(5) Connect battery negative cable.
(6) Start engine and check fan operation.
WATER PUMP - 2.4L
DESCRIPTION
The water pump has a cast aluminum body and
housing with a stamped steel impeller. The water
pump bolts directly to the block (Fig. 14). The cylin-
der block to water pump seal is provided by a rubber
O-ring. The water pump is driven by the engine tim-
ing belt.
OPERATION
The water pump is the heart of the cooling system.
The coolant is pumped through the engine block, cyl-
inder head, heater core, and radiator.
REMOVAL - 2.4L ENGINE
(1) Disconnect negative cable from battery.
(2) Raise vehicle on a hoist.
(3) Remove the accessory drive belts (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the belt tensioner.
(5) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(6) Remove the generator.
(7) Remove the power steering pump.
(8) Remove the A/C compressor.
Fig. 13 Radiator Cooling Fan - Typical
1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN
Fig. 14 Water Pump
1 - CYLINDER BLOCK
2 - WATER PUMP
KJENGINE7s-27
RADIATOR FAN - ELECTRIC (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
5. Radio faulty. 5. Refer to appropriate Diagnostic Service
Manual.
CLOCK WILL NOT KEEP
SET TIME1. Fuse faulty. 1. Check Ignition-Off Draw (IOD) fuse in the
Junction Block (JB). Replace fuse, if required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. Refer to appropriate Diagnostic Service
Manual.
POOR RADIO RECEPTION 1. Antenna faulty. 1. (Refer to 8 - ELECTRICAL/AUDIO/ANTENNA
BODY & CABLE - DIAGNOSIS AND TESTING).
2. Radio ground faulty. 2. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
3. Radio noise suppression
faulty.3. Repair or replace ground strap as necessary.
4. Radio faulty. 4. Refer to appropriate Diagnostic Service
Manual.
NO/POOR TAPE
OPERATION1. Faulty tape. 1. Insert known good tape and test operation.
2. Foreign objects behind
tape door.2. Remove foreign objects and test operation.
3. Dirty cassette tape head. 3. Clean head with Mopar Cassette Head
Cleaner.
4. Faulty tape deck. 4. Exchange or replace radio, if required.
NO COMPACT DISC
OPERATION1. Faulty CD. 1. Insert known good CD and test operation.
2. Foreign material on CD. 2. Clean CD and test operation.
3. Condensation on CD or
optics.3. Allow temperature of vehicle interior to stabilize
and test operation.
4. Faulty CD player. 4. Refer to appropriate Diagnostic Service
Manual.
AMPLIFIER CHOKE AND
RELAY
DESCRIPTION
Models equipped with the premium speaker pack-
age have a amplifier choke and relay. The amplifier
choke and relay is mounted to the lower instrument
panel above the accelerator pedal.
The amplifier choke and relay should be checked if
there is no sound output from the speakers. The
amplifier choke and relay can not be repaired or
adjusted and, if faulty or damaged, the unit must be
replaced.
OPERATION
The amplifier choke and relay is used to control
the supply of fused battery current to the front door
speaker-mounted dual amplifiers. The speaker relay
is energized by a fused 12 volt output from the radio
receiver whenever the radio is turned on. For com-
plete circuit diagrams, refer to the appropriate wir-
ing information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
KJAUDIO 8A - 3
AUDIO (Continued)