2002 JEEP LIBERTY motor

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Output Speed Sensor BK Left Side of Transmission 5
Overhead Map/Courtesy Lamp BK Overhead Console N/S
Oxygen Sensor 1/1 Upstream (2.4L) BK Right Side of Engine 12
Oxygen Sensor 1/1 Upstream (3.7L) BK Lower Left Side of Engine 3
Oxygen Sensor 1/2 Downstream
(2.4L)NAT Right Side of Transmission 11, 12
Oxygen Sensor 1/2 Downstream
(3.7L)NAT Left Side of Transmission 5, 7
Oxygen Sensor 2/1 Upstream (3.7L) BK Lower Right Side of Engine 4
Oxygen Sensor 2/2 Downstream
(3.7L)NAT Right Side of Transmission 6
Park Brake Switch BK Center Console 36, 40
Passenger Airbag YL Right Side Instrument Panel N/S
Passenger Seat Belt Switch LG At Passenger Seat N/S
Power Mirror Switch WT In Left Front Door 41
Power Outlet RD Center of Instrument Panel N/S
Power Steering Pressure Switch BK Left Front Side of Engine 3, 15
Power Window Master Switch LG Center Console 36, 40
Powertrain Control Module C1 (2.4L) BK At Powertrain Control Module 13, 14
Powertrain Control Module C1 (3.7L) BK At Powertrain Control Module 8, 9, 10
Powertrain Control Module C2 WT At Powertrain Control Module 8, 9, 10, 13, 14
Powertrain Control Module C3 GY At Powertrain Control Module 31
Radiator Fan Motor BK Right Front Side of Engine
Compartment28
Radiator Fan Relay BK Left Front Side of Engine
Compartment29
Radio C1 GY Rear of Radio N/S
Radio C2 Rear of Radio N/S
Radio C3 Rear of Radio N/S
Radio Choke GY Center of Instrument Panel N/S
Rear Map/Reading Lamp BK Overhead Console N/S
Rear Power Outlet RD Right Rear Quarter Panel 44, 45, 48
Rear Power Window Switch WT Center Console 36, 40
Rear Wheel Speed Sensor BK On Rear Axle N/S
Rear Window Defogger BK At Rear Window 46
Rear Wiper Motor BK In Tailgate 46
Red Brake Warning Indicator Switch
(LHD)GY Left Rear Side of Engine
Compartment31
Red Brake Warning Indicator Switch
(RHD)GY Right Rear Side of Engine
Compartment26
Right Curtain Airbag YL Right Mid B-Pillar 34, 39
Right Cylinder Lock Switch (Except
Base)LG In Right Front Door 41
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-7
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Right Door Lock Switch (Except
Base)BK In Right Front Door 41
Right Fog Lamp BK Right Side of Bumper N/S
Right Front Door Ajar Switch (Base) BK In Right Front Door N/S
Right Front Door Lock Motor/Ajar
Switch (Except Base)BK In Right Front Door 41
Right Front Door Speaker BK In Right Front Door 41
Right Front Impact Sensor BK Right Front Side of Engine
Compartment28
Right Front Park/Turn Signal Lamp BK At Lamp N/S
Right Front Power Window Motor LG In Right Front Door 41
Right Front Wheel Speed Sensor BK Right Rear Lower Side of
Engine Compartment25
Right Headlamp (BUX) Right Front Side of Engine
CompartmentN/S
Right Headlamp (Except BUX) DB Right Front Side of Engine
CompartmentN/S
Right Heated Seat Assembly LG At Right Seat N/S
Right Heated Seat Switch BK At Right Seat N/S
Right Instrument Panel Lamp BK Right Side of Instrument
PanelN/S
Right Instrument Panel Speaker WT Right Side of Instrument
Panel33, 37
Right Leveling Motor (BUX) BK At Right Headlamp N/S
Right Position Lamp (BUX) BK Right Front Corner of Vehicle N/S
Right Power Mirror WT In Right Front Door 41
Right Power Seat Motors BK At Right Seat N/S
Right Power Seat Switch GN At Right Seat N/S
Right Rear Door Ajar Switch (Base) BK In Right Rear Door N/S
Right Rear Door Lock Motor/Ajar
Switch (Except Base)BK In Right Rear Door 42
Right Rear Door Speaker At Speaker 42
Right Rear Power Window Motor LG In Right Rear Door 42
Right Remote Radio Switch BK On Steering Wheel N/S
Right Side Impact Airbag Control
Module (RSIACM)YL Lower Right B-Pillar 34, 39
Right Side Marker Lamp BK Right Front Fender N/S
Right Side Repeater Lamp (BUX) BK Right Front Fender N/S
Right Speed Control Switch WT On Steering Wheel N/S
Right Tail/Stop Lamp BK Right Rear Quarter Panel 45
Right Visor/Vanity Lamp WT On Visor N/S
Sentry Key Immobilizer Module BK Under Left Side of
Instrument PanelN/S
Shifter Assembly WT Center Console 36, 40
8Wa - 91 - 8 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONKJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Siren (BUX) Right Front Side of Engine
Compartment28
Speed Control Servo BK Right Rear Side of Engine
Compartment27
Sunroof Motor LG Overhead Console N/S
Sunroof Switch BK Overhead Console N/S
Tailgate Cylinder Lock Switch LG In Tailgate 46
Tailgate Flip-Up Ajar Switch GY In Tailgate 46
Tailgate Lock Motor/Ajar Switch BK In Tailgate 46
Throttle Position Sensor WT On Throttle Body 1
Trailer Tow Brake Lamp Relay Right Quarter Panel 47
Trailer Tow Circuit Breaker Right Quarter Panel N/S
Trailer Tow Connector BK At Trailer Hitch 47, 48
Trailer Tow Right Turn Relay Right Quarter Panel 47
Trailer Tow Relay Right Quarter Panel 47
Trailer Tow Left Turn Relay Right Quarter Panel 47
Transfer Case Position Sensor BK Rear Side of Transmission 5, 7, 11, 12, 22
Transmission Control Module (3.7L)
(LHD)BK Right Rear Side of Engine
Compartment8, 9
Transmission Control Module (3.7L)
(RHD)BK Left Rear Side of Engine
Compartment10
Transmission Solenoid/TRS
Assembly (3.7L)GY Left Side of Transmission 5
Under Hood Lamp BK Underside of Hood 24
Washer Fluid Level Switch LG At Washer Fluid Reservoir 28
Water In Fuel Sensor (Diesel) Left Rear Side of Engine
Compartment19
GROUNDS
GROUND NUMBER LOCATION FIG.
G100 Left Side of Engine Compartment 8, 9, 10, 14, 19
G101 (2.4L) Left Side of Engine Compartment 11
G102 (LHD) Right Rear Side of Engine Compartment 9
G102 (RHD) Left Rear Side of Engine Compartment 10
G103 (3.7L) Right Front Side of Engine 4
G103 (Diesel) Right Front Side of Engine 20
G104 Near Engine Control Module C2 19
G105 Left Side of Engine Compartment N/S
G106 Left Side of Engine Compartment N/S
G110 Left Side of Engine Compartment 30
G111 Left Front Side of Engine Compartment 29
G112 Left Front Side of Engine Compartment 29
G200 Near Body Control Module N/S
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-9
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE NUMBER LOCATION FIG.
S151 (Diesel) In Trough Near T/O for Accelerator Pedal Position Sensor 19
S152 In Trough Near T/O for Fuel Injector No.4 2
S153 (2.4L) Near T/O for Coil Rail 11, 12
S153 (3.7L) Near T/O for Idle Air Control Motor 1
S153 (Diesel) In Trough Near T/O for Generator 20, 23
S154 Near T/O for Engine Starter Motor 2, 4, 20
S155 Near T/O for Knock Sensor 1
S156 (2.4L) In Trough Near T/O for C112 13, 14
S156 (3.7L) Near T/O for Powertrain Control Module C1 8
S156 (Diesel) Near T/O for A/C Compressor Clutch 20
S157 Near T/O for Oxygen Sensor 2/2 Downstream N/S
S158 In Trough Near T/O for C112 8
S159 Near T/O for Knock Sensor 1, 8
S160 In T/O for C104 10
S161 Near T/O for Oxygen Sensor 1/2 Downstream 5, 7
S163 In T/O for Transmission Control Module 10
S164 In Trough on Right Rear Side of Engine Compartment 10
S165 In Trough on Right Rear Side of Engine Compartment 10
S167 In T/O for Transmission Control Module 10
S168 Near T/O for Fuel Injector No.6 2
S169 (2.4L) Near T/O for C101 11
S169 (3.7L) Near T/O for Oxygen Sensor 1/1 Upstream 1, 3
S169 (Diesel) Near T/O for Generator 20
S170 Near T/O for C103 8, 13, 16
S175 In Trough on Top of Engine 22, 23
S177 In Trough Near T/O for G100 19
S178 Near T/O for Oxygen Sensor 2/2 Downstream 6
S180 Near T/O for C103 8
S181 In Trough Near T/O for G100 19
S184 Near T/O for Powertrain Control Module C1 8
S200 Near T/O for C201 N/S
S201 Near T/O for Left Instrument Panel Lamp N/S
S204 Near T/O for Data Link Connector N/S
S205 In T/O for C100 N/S
S206 Near T/O for Multifunction Switch C2 N/S
S207 In T/O for C100 N/S
S208 Near T/O for G202 N/S
S210 Near T/O for Left Instrument Panel Lamp N/S
S212 Near T/O for Diagnostic Junction Port N/S
S213 Near T/O for Diagnostic Junction Port N/S
S214 Near T/O for Airbag Control Module C1 (ORC C1) N/S
S215 Near T/O for Multifunction Switch C2 N/S
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-11
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE NUMBER LOCATION FIG.
S336 (RHD) Near T/O for Right Instrument Panel Speaker 37
S338 Near T/O for C201 33, 37
S340 Near T/O for C201 33
S341 Near T/O for C201 33
S342 (Base) Near T/O for Right Instrument Panel Speaker 33
S344 Near T/O for Right Instrument Panel Speaker 33
S346 In T/O for Trailer Tow Relays 47
S347 Near T/O for Right Tail/Stop Lamp 45
S348 Near T/O for Right Tail/Stop Lamp 45
S349 Near T/O for License Lamp 45
S350 Near T/O for License Lamp 45
S351 In T/O for Rear Window Defogger 46
S352 In T/O for Rear Window Defogger N/S
S356 Near T/O for Center High Mounted Stop Lamp N/S
S360 Near T/O for Left Power Mirror 41
S361 Near T/O for Left Power Mirror 41
S362 Near T/O for Power Mirror Switch 41
S363 Near T/O for Left Front Door Speaker N/S
S364 Near T/O for Left Front Door Speaker N/S
S370 Near T/O for Right Power Mirror 41
S371 Near T/O for Right Door Lock Switch 41
S372 Near T/O for Right Front Door Speaker N/S
S373 Near T/O for Right Front Door Speaker N/S
S380 Near T/O for Rear Wiper Motor N/S
S381 Near T/O for Tailgate Cylinder Lock Switch N/S
S382 Near T/O for License Lamp N/S
S390 Near T/O for Intrusion Sensor N/S
S391 Near T/O for Left Visor/Vanity Lamp N/S
S392 Near T/O for Left Visor/Vanity Lamp N/S
S393 Near T/O for Intrusion Sensor N/S
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-13
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
3. Incorrect ring size installed. 3. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
4. Worn valve guides. 4. Ream guides and replace valves
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
5. Leaking valve guide seals. 5. Replace valve guide seals.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(5) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(6) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(7) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylin-
ders.
(8) (Refer to 9 - ENGINE - SPECIFICATIONS) for
the correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner.
(6) Calibrate the tester according to the manufac-
turer's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
Set piston of cylinder to be tested at TDC compres-
sion,While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to CYLINDER COMBUSTION PRESSURE
LEAKAGE DIAGNOSIS CHART .
9 - 8 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
AIR ESCAPES THROUGH
THROTTLE BODYIntake valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary.
Inspect valve springs. Replace as
necessary.
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary.
Inspect valve springs. Replace as
necessary.
AIR ESCAPES THROUGH
RADIATORHead gasket leaking or cracked
cylinder head or blockRemove cylinder head and inspect.
Replace defective part
MORE THAN 50% LEAKAGE
FROM ADJACENT CYLINDERSHead gasket leaking or crack in
cylinder head or block between
adjacent cylindersRemove cylinder head and inspect.
Replace gasket, head, or block as
necessary
MORE THAN 25% LEAKAGE AND
AIR ESCAPES THROUGH OIL
FILLER CAP OPENING ONLYStuck or broken piston rings;
cracked piston; worn rings and/or
cylinder wallInspect for broken rings or piston.
Measure ring gap and cylinder
diameter, taper and out-of-round.
Replace defective part as necessary
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE GASKET
SURFACE PREPARATION
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
Neveruse the following to clean gasket surfaces:
²Metal scraper
²Abrasive pad or paper to clean cylinder block
and head
²High speed power tool with an abrasive pad or a
wire brush (Fig. 1)
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:
²Solvent or a commercially available gasket
remover
²Plastic or wood scraper (Fig. 1)
²Drill motor with 3M RolocŸ Bristle Disc (white
or yellow) (Fig. 1)
CAUTION: Excessive pressure or high RPM (beyond
the recommended speed), can damage the sealing
surfaces. The mild (white, 120 grit) bristle disc is
recommended. If necessary, the medium (yellow, 80
grit) bristle disc may be used on cast iron surfaces
with care.
STANDARD PROCEDURE - REPAIR DAMAGED
OR WORN THREADS
CAUTION: Be sure that the tapped holes maintain
the original center line.
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
Fig. 1 Proper Tool Usage For Surface Preparation
1 - ABRASIVE PAD
2 - 3M ROLOCŸ BRISTLE DISC
3 - PLASTIC/WOOD SCRAPER
KJENGINE - 3.7L 9 - 9
ENGINE - 3.7L (Continued)

²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
STANDARD PROCEDURE - ENGINE CORE AND
OIL GALLERY PLUGS
Using a blunt tool such as a drift and a hammer,
strike the bottom edge of the cup plug. With the cup
plug rotated, grasp firmly with pliers or other suit-
able tool and remove plug (Fig. 2).
CAUTION: Do not drive cup plug into the casting as
restricted cooling can result and cause serious
engine problems.
Thoroughly clean inside of cup plug hole in cylin-
der block or head. Be sure to remove old sealer.
Lightly coat inside of cup plug hole with Mopart
Stud and Bearing Mount. Make certain the new plug
is cleaned of all oil or grease. Using proper drive
plug, drive plug into hole so that the sharp edge of
the plug is at least 0.5 mm (0.020 in.) inside the
lead-in chamfer.
It is not necessary to wait for curing of the sealant.
The cooling system can be refilled and the vehicle
placed in service immediately.
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove hood. Mark hood hinge location for
reinstallation.
(3) Remove air cleaner assembly.(4) Remove radiator core support bracket.
(5) Remove fan shroud with electric fan assembly.
(6) Remove mechanical cooling fan.
(7) Remove drive belt.
NOTE: It is NOT necessary to discharge the A/C
system to remove the engine.
(8) Remove A/C compressor and secure away from
engine with lines attached.
(9) Remove generator and secure away from
engine.
NOTE: Do NOT remove the phenolic pulley from the
P/S pump. It is not required for P/S pump removal.
(10) Remove power steering pump with lines
attached and secure away from engine.
(11) Drain cooling system.
(12) Remove coolant bottle.
(13) Disconnect the heater hoses from the engine.
(14) Disconnect heater hoses from heater core and
remove hose assembly.
(15) Disconnect throttle and speed control cables.
(16) Remove upper radiator hose from engine.
(17) Remove lower radiator hose from engine.
(18) Disconnect the engine to body ground straps
at the left side of cowl.
(19) Disconnect the engine wiring harness at the
following points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(20) Remove coil over plugs.
(21) Release fuel rail pressure.
(22) Remove fuel rail and secure away from
engine.
NOTE: It is not necessary to release the quick con-
nect fitting from the fuel supply line for engine
removal.
(23) Remove the PCV hose.
(24) Remove the breather hoses.
(25) Remove the vacuum hose for the power brake
booster.
(26) Disconnect knock sensors.
(27) Remove engine oil dipstick tube.
(28) Remove intake manifold.
(29) Install engine lift plate.
Fig. 2 Core Hole Plug Removal
1 - CYLINDER BLOCK
2 - REMOVE PLUG WITH PLIERS
3 - STRIKE HERE WITH HAMMER
4 - DRIFT PUNCH
5 - CUP PLUG
9 - 10 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)