2002 JEEP LIBERTY Crankshaft

POWERTRAIN CONTROL MODULE-C1 (3.7L) - BLACK 32 WAY
CAV CIRCUIT FUNCTION
1 K93 14TN/OR COIL ON PLUG DRIVER NO. 3
2 F1 18DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
3 K94 14TN/LG COIL ON PLUG DRIVER NO. 4
4 K4 18BK/LB SENSOR GROUND
5 K96 14TN/LB COIL ON PLUG DRIVER NO. 6
6 T41 18BK/WT (A/T) PARK/NEUTRAL POSITION SWITCH SENSE
7 K91 14TN/RD COIL ON PLUG DRIVER NO.1
8 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
9- -
10 K60 18YL/BK IDLE AIR CONTROL NO. 2 DRIVER
11 K40 18BR/WT IDLE AIR CONTROL NO. 1 DRIVER
12 K10 18DB/OR POWER STEERING PRESSURE SWITCH SENSE
13 T141 18 YL/RD (M/T) FUSED IGNITION SWITCH OUTPUT (START)
13 F45 18YL/BR (A/T) FUSED IGNITION SWITCH OUTPUT (START)
14 K77 18BR/WT TRANSFER CASE POSITION SENSOR INPUT
15 K21 18BK/RD INTAKE AIR TEMPERATURE SENSOR SIGNAL
16 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
17 K7 18OR 5 VOLT SUPPLY
18 K44 18TN/YL CAMSHAFT POSITION SENSOR SIGNAL
19 K39 18GY/RD IDLE AIR CONTROL NO. 3 DRIVER
20 K59 18VT/BK IDLE AIR CONTROL NO. 4 DRIVER
21 K95 14TN/DG COIL ON PLUG DRIVER NO. 5
22 A14 16RD/WT FUSED B(+)
23 K22 18OR/DB THROTTLE POSITION SENSOR SIGNAL
24 K41 18BK/DG OXYGEN SENSOR 1/1 SIGNAL
25 K141 18TN/WT OXYGEN SENSOR 1/2 SIGNAL
26 K241 18LG/RD OXYGEN SENSOR 2/1 SIGNAL
27 K1 18DG/RD MANIFOLD ABOLUTE PRESSURE SENSOR SIGNAL
28 - -
29 K341 18TN/WT OXYGEN SENSOR 2/2 SIGNAL
30 - -
31 Z107 14BK/DB GROUND
32 Z107 14BK/DB GROUND
POWERTRAIN CONTROL MODULE-C2 (GAS) - WHITE 32 WAY
CAV CIRCUIT FUNCTION
1- -
2- -
3- -
4 K11 18WT/DB FUEL INJECTOR NO. 1 DRIVER
5 K13 18YL/WT FUEL INJECTOR NO. 3 DRIVER
6 K38 18GY (3.7L) FUEL INJECTOR NO. 5 DRIVER
7- -
8- -
9 K92 14TN/PK (3.7L) COIL ON PLUG DRIVER NO. 2
9 K17 18DB/TN (2.4L) IGNITION COIL NO. 2 DRIVER
10 K20 18DG GENERATOR FIELD
11 - -
12 K58 18BR/DB (3.7L) FUEL INJECTOR NO. 6 DRIVER
8Wa - 80 - 82 8W-80 CONNECTOR PIN-OUTSKJ

TRANSMISSION CONTROL MODULE (3.7L) - BLACK 60 WAY
CAV CIRCUIT FUNCTION
1 T1 18LG/BK TRS T1 SENSE
2 T4 18PK/OR TRS T2 SENSE
3 T3 18VT TRS T3 SENSE
4- -
5- -
6 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
7 D21 18PK SCI TRANSMIT
8 F45 18YL/BR FUSED IGNITION SWITCH OUTPUT (START)
9 T9 18OR/BK OVERDRIVE PRESSURE SWITCH SENSE
10 T10 18YL/DG TORQUE MANAGEMENT REQUEST SENSE
11 F1 18DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 K22 18OR/DB THROTTLE POSITION SENSOR SIGNAL
13 T13 18DB/BK SPEED SENSOR GROUND
14 T14 18LG/WT OUTPUT SPEED SENSOR SIGNAL
15 K30 18PK TRANSMISSION CONTROL RELAY CONTROL
16 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
17 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
18 T591 18YL/DB PRESSURE CONTROL SOLENOID CONTROL
19 T119 18WT/DB 2C SOLENOID CONTROL
20 T20 18LB LOW/REVERSE SOLENOID CONTROL
21 - -
22 - -
23 - -
24 - -
25 - -
26 - -
27 - -
28 - -
29 T29 18GY UNDERDRIVE PRESSURE SWITCH SENSE
30 T38 18VT/TN LINE PRESSURE SENSOR SIGNAL
31 - -
32 - -
33 - -
34 - -
35 - -
36 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
37 Z113 14BK/YL GROUND
38 T39 18GY/LB 5 VOLT SUPPLY
39 Z113 14BK/YL GROUND
40 T140 18VT/LG MS SOLENOID CONTROL
41 T411 18WT/PK TRS T41 SENSE
42 T42 18VT/WT TRS T42 SENSE
43 D25 18VT/YL PCI BUS
44 - -
45 - -
46 D20 18LG SCI RECEIVE
47 T147 18LB 2C PRESSURE SWITCH SENSE
48 T48 18DB 4C PRESSURE SWITCH SENSE
49 T6 18OR/WT OVERDRIVE OFF SWITCH SENSE
50 T50 18DG LOW/REVERSE PRESSURE SWITCH SENSE
51 K4 18BK/LB SENSOR GROUND
52 T52 18RD/BK INPUT SPEED SENSOR SIGNAL
53 Z112 14BK GROUND
8Wa - 80 - 98 8W-80 CONNECTOR PIN-OUTSKJ

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Coil On Plug No.5 (3.7L) BK Left Side of Engine Near
Fuel Injector No.51
Coil On Plug No.6 (3.7L) BK Right Side of Engine Near
Fuel Injector No.62
Coil Rail (2.4L) BK Right Side of Engine 11, 12
Combination Flasher WT Under Left Side of
Instrument PanelN/S
Compass Mini-Trip Computer BK At Overhead Console N/S
Controller Antilock Brake BK Left Side of Engine
Compartment30
Crankshaft Position Sensor (2.4L) BK Top of Engine N/S
Crankshaft Position Sensor (3.7L) BK Right Lower Side of Engine 4
Crankshaft Position Sensor (Diesel) BK Right Rear Side of Engine 17
Data Link Connector BK Under Center of Instrument
PanelN/S
Diagnostic Junction Port BK Under Center of Instrument
Panel49
Dome Lamp (Base) BK On Headliner N/S
Driver Airbag Squib 1 GY In Steering Wheel N/S
Driver Airbag Squib 2 BK In Steering Wheel N/S
Driver Seat Belt Switch LG At Drive Seat N/S
Driver Seat Belt Tensioner (LHD) YL Lower Left B-Pillar 35
Driver Seat Belt Tensioner (RHD) YL Lower Right B-Pillar 39
EGR Solenoid Right Rear Side of Engine
Compartment27
Engine Control Module C1 BK Left Rear Side of Engine
Compartment19
Engine Control Module C2 BK Left Rear Side of Engine
Compartment19
Engine Coolant Level Sensor (Diesel) LG Rear Side of Engine
Compartment18
Engine Coolant Temperature Sensor
(Diesel)BK Left Side of Engine 20
Engine Coolant Temperature Sensor
(Gas)BK Front Side of Engine 2
Engine Oil Pressure Sensor (2.4L) BK Top of Engine N/S
Engine Oil Pressure Sensor (3.7L) BK Left Front Side of Engine 3
Engine Oil Pressure Sensor (Diesel) BK Right Rear Side of Engine 17
Engine Starter Motor Right Front Side of Engine 20
Evap/Purge Solenoid BK At Solenoid N/S
Flip-Up Glass Release Motor BK In Tailgate 46
Flip-Up Glass Release Switch WT In Tailgate 46
Front Washer Pump BK Right Front Side of Engine
Compartment28
Front Wiper Motor (LHD) BK Left Side of Cowl 24
8Wa - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONKJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

ENGINE BLOCK
DESCRIPTION.........................39
STANDARD PROCEDURE - CYLINDER BORE
HONING............................39
CLEANING............................39
INSPECTION..........................40
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - CONNECTING
ROD BEARING - FITTING...............40
CRANKSHAFT
DESCRIPTION.........................42
REMOVAL.............................43
INSPECTION..........................43
INSTALLATION.........................43
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE
MAIN BEARING - FITTING...............45
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................46
INSTALLATION.........................47
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................48
INSTALLATION.........................48
FLEX PLATE
REMOVAL.............................49
INSTALLATION.........................49
PISTON & CONNECTING ROD
DESCRIPTION.........................49
STANDARD PROCEDURE
CONNECTING ROD BEARING - FITTING . . . 49
STANDARD PROCEDURE - PISTON
FITTING.............................50
REMOVAL.............................50
CLEANING............................51
INSPECTION..........................51
INSTALLATION.........................51
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING.............................52
VIBRATION DAMPER
REMOVAL.............................54
INSTALLATION.........................55
STRUCTURAL COVER
DESCRIPTION.........................55
OPERATION...........................55
REMOVAL.............................55
INSTALLATION.........................55
FRONT MOUNT
REMOVAL.............................56
INSTALLATION.........................57
REAR MOUNT
REMOVAL.............................57
INSTALLATION.........................57
LUBRICATION
DESCRIPTION.........................57
OPERATION...........................58DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK...............................60
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE..........................60
DIAGNOSIS AND TESTING - REAR SEAL
AREA LEAKS.........................61
OIL
STANDARD PROCEDURE - ENGINE OIL.....61
OIL FILTER
REMOVAL.............................63
INSTALLATION.........................63
OIL PAN
DESCRIPTION.........................63
REMOVAL.............................63
CLEANING............................63
INSPECTION..........................63
INSTALLATION.........................64
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION.........................65
OPERATION...........................65
REMOVAL.............................65
INSTALLATION.........................65
OIL PUMP
REMOVAL.............................65
DISASSEMBLY.........................65
INSPECTION..........................66
ASSEMBLY............................67
INSTALLATION.........................67
INTAKE MANIFOLD
DESCRIPTION.........................68
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS.....................68
REMOVAL.............................68
INSTALLATION.........................69
EXHAUST MANIFOLD
DESCRIPTION.........................69
REMOVAL.............................69
INSTALLATION.........................70
VALVE TIMING
DESCRIPTION.........................71
OPERATION...........................71
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR.......71
SERVICE PROCEDURES...............72
BALANCE SHAFT
REMOVAL.............................74
INSTALLATION.........................74
TIMING BELT / CHAIN COVER(S)
REMOVAL.............................74
INSTALLATION.........................76
IDLER SHAFT
REMOVAL.............................77
INSTALLATION.........................77
TIMING BELT/CHAIN AND SPROCKET(S
REMOVAL.............................77
INSPECTION..........................79
INSTALLATION.........................80
9 - 2 ENGINE - 3.7LKJ

ENGINE - 3.7L
DESCRIPTION
The 3.7 liter (226 CID) six-cylinder engine is an
90É single overhead camshaft engine. The cast iron
cylinder block is made up of two different compo-
nents; the first component is the cylinder bore and
upper block, the second component is the bedplate
that comprises the lower portion of the cylinder block
and houses the lower half of the crankshaft mainbearings. The cylinders are numbered from front to
rear with the left bank being numbered 1,3,and 5
and the right bank being numbered 2,4, and 6. The
firing order is 1±6±5±4±3±2. The engine serial num-
ber is located at the right front side of the engine
block
3.7 L ENGINE
KJENGINE - 3.7L 9 - 3

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTIONS
NOISY VALVES 1. High or low oil level in
crankcase.1. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
SPECIFICATIONS).
2. Thin or diluted oil. 2. Change oil and filter.
3. Low oil pressure. 3. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
4. Dirt in lash adjusters. 4. Clean or replace as necessary.
5. Worn rocker arms. 5. Replace as necessary.
7. Worn valve guides. 7. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
8. Excessive runout of valve seats
on valve faces.8. Service valves and valve seats.
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
ENGINE VIBRATION 1. Counter Balance Shaft not timed
properly1. Refer to Engine Timing in this
section
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
SPECIFICATIONS).
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Connecting rod journal
out-of-round.5. Service or replace crankshaft.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
SPECIFICATIONS).
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check thrust washers for wear.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
9 - 6 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - LUBRICATION
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Gaskets and O-Rings. 1.
(a) Misaligned or damaged. (a) Replace as necessary.
(b) Loose fasteners, broken or
porous metal parts.(b) Tighten fasteners, Repair or
replace metal parts.
2. Crankshaft rear seal 2. Replace as necessary (Refer to 9
- ENGINE/ENGINE BLOCK/
CRANKSHAFT OIL SEAL - REAR -
REMOVAL).
3. Crankshaft seal flange.
Scratched, nicked or grooved.3. Polish or replace crankshaft.
4. Oil pan flange cracked. 4. Replace oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN -
REMOVAL).
5. Timing chain cover seal
damaged.5. Re-seal timing cover.
6. Scratched or damaged vibration
damper hub.6. Polish or replace damper.
OIL PRESSURE DROP 1. Low oil level. 1. Check and correct oil level.
2. Faulty oil pressure sending unit. 2. Replace sending unit (Refer to 9
- ENGINE/LUBRICATION/OIL
PRESSURE SENSOR/SWITCH -
REMOVAL).
3. Low oil pressure. 3. Check oil pump and bearing
clearance.
4. Clogged oil filter. 4. Replace oil filter (Refer to 9 -
ENGINE/LUBRICATION/OIL FILTER
- REMOVAL).
5. Worn oil pump. 5. Replace oil pump (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP
- REMOVAL).
6. Thin or diluted oil. 6. Change oil and filter.
7. Excessive bearing clearance. 7. Replace as necessary.
8. Oil pump relief valve stuck. 8. Replace oil pump (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP
- REMOVAL).
9. Oil pump suction tube loose,
damaged or clogged.9. Replace as necessary.
KJENGINE - 3.7L 9 - 7
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)