2002 JEEP LIBERTY removal

(14) Continue lowering tank while guiding remain-
ing hoses and lines.
(15) If fuel tank is to be replaced, remove LDP,
fuel filter and fuel pump module from tank. Refer to
Leak Detection Pump, Fuel Filter and Fuel Pump
Module Removal/Installation procedures.
INSTALLATION
(1) If fuel tank is to be replaced, install LDP, fuel
filter and fuel pump module to tank. Refer to Leak
Detection Pump, Fuel Filter and Fuel Pump Module
Removal/Installation procedures.
(2) Position fuel tank to hydraulic jack.
(3) Raise tank while carefully guiding vent tubes/
hoses through frame rail and crossmember. Before
tank reaches body, connect electrical connector to
Leak Detection Pump (LDP).
(4) Continue raising tank until positioned to body.
(5) Attach two fuel tank mounting straps and 4
mounting bolts. Tighten bolts to 61 N´m (45 ft. lbs.)
torque.
(6) Connect 2 hoses to body retention clip at left/
front of tank.
(7) Connect fuel filter fuel line to main fuel line
(snaps together). After connecting, snap this line into
body retention clip. Also connect LDP vacuum hose
near this point.(8) Install fuel fill hose and hose clamp to fuel
tank fitting. Rotate hose until white painted index
mark on hose (Fig. 42) is located between alignment
notches on fuel tank fitting. Tighten clamp to 3.4
N´m (30 in. lbs.) torque.
(9) Connect fresh air and recirculation lines to fuel
fill tube.
(10) Connect 3/4º lines to Leak Detection Pump
(LDP).
(11) Connect 3/4º flow management valve hose to
EVAP canister.
(12) Snap remaining lines into body retention clip
at front/center of fuel tank.
(13) If equipped, install fuel tank skid plate,
trailer hitch and tow hooks. Refer to Tow Hooks,
Trailer Hitch or Skid Plate in 23, Body for removal/
installation procedures.
(14) Lower vehicle.
(15) Attach (snap on) 2 fuel filter fuel lines to top
of fuel pump module.
(16) Install electrical connector to top of fuel pump
module.
(17) Connect negative battery cable to battery.
(18) Fill fuel tank with fuel.
(19) Start engine and check for fuel leaks near top
of module.
(20) Apply silicone sealant to bottom of fuel pump
module metal access plate.
Fig. 42 FUEL FILL HOSE AT TANK
1 - FUEL FILL HOSE AT TANK
2 - HOSE CLAMP
3 - WHITE PAINTED INDEX MARK
4 - ALIGNMENT NOTCHES
5 - LEFT SIDE OF FUEL TANK
6 - FUEL FILL FITTINGFig. 43 LDP ELECTRICAL CONNECTOR
1 - LEAK DETECTION PUMP (LDP)
2 - ELECTRICAL CONNECTOR
3 - FUEL FILTER
KJFUEL DELIVERY 14 - 27
FUEL TANK (Continued)

(21) Install fuel pump module metal access plate
and 4 nuts. Tighten nuts to 3 N´m (26 in. lbs.)
torque.
(22) Position carpet and install 2 new cargo clamp
rivets into each cargo holdown clamp.
FUEL TANK CHECK VALVE
DESCRIPTION
The fuel tank is equipped with a check valve. The
valve (also referred to as a control valve) is located in
the top section of the fuel pump module assembly
(Fig. 1).
OPERATION
The fuel tank check valve (also referred to as
either a control valve, one-way check valve or float
valve) will prevent fuel flow through the fuel tank
vent in the event of an accidental vehicle rollover. It
is also used as a part of the ORVR system. The
EVAP canister and ORVR system draw fuel vapors
from the fuel tank through this valve. Refer to ORVR
in Emissions for additional information.
The valve may be serviced by replacing the upper
section of the fuel pump module assembly.
REMOVAL
The fuel tank check (control) valve is attached into
the top section of the fuel pump module (Fig. 44). If
replacement is necessary, the top section of the fuel
pump module must be replaced. Refer to Fuel Pump
Module Removal/Installation.
INSTALLATION
The fuel tank check (control) valve is attached to
the top section of the fuel pump module. If replace-
ment is necessary, the top section of the fuel pump
module must be replaced. Refer to Fuel Pump Mod-
ule Removal/Installation.
INLET FILTER
REMOVAL
The fuel pump inlet filter is located on the bottom/
side of the lower fuel pump module section (Fig. 45).
The fuel pump module assembly is located in the fuel
tank.
(1) Remove lower section of fuel pump module.
Refer to Fuel Pump Module Removal/Installation.
(2) Remove filter by prying from pump module
with 2 small screwdrivers. Filter is snapped to mod-
ule with 2 release tabs (Fig. 45).
(3) Clean filter entrance into pump module open-
ing.
INSTALLATION
(1) Snap new filter to bottom of fuel pump module.
(2) Install lower section of fuel pump module.
Refer to Fuel Pump Module Removal/Installation.
Fig. 44 UPPER SECTION - FUEL PUMP MODULE
1 - UPPER SECTION - FUEL PUMP MODULE
2 - FUEL TANK CHECK (CONTROL) VALVE
Fig. 45 INLET FILTER
1 - INLET FILTER
2 - RELEASE TABS (2)
3 - BOTTOM OF FUEL PUMP MODULE
14 - 28 FUEL DELIVERYKJ
FUEL TANK (Continued)

FUEL INJECTION
TABLE OF CONTENTS
page page
FUEL INJECTION
DESCRIPTION.........................29
ACCELERATOR PEDAL
REMOVAL.............................29
INSTALLATION.........................30
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................30
OPERATION...........................31
REMOVAL.............................31
INSTALLATION.........................32
FUEL INJECTOR
DESCRIPTION.........................33
OPERATION
OPERATION - FUEL INJECTOR..........33
OPERATION - PCM OUTPUT............33
DIAGNOSIS AND TESTING - FUEL INJECTOR . 33
REMOVAL.............................34
INSTALLATION.........................34
FUEL PUMP RELAY
DESCRIPTION.........................34
OPERATION...........................34
DIAGNOSIS AND TESTING - FUEL PUMP
RELAY..............................34
REMOVAL.............................34
INSTALLATION.........................34
IDLE AIR CONTROL MOTOR
DESCRIPTION.........................35
OPERATION...........................35
REMOVAL.............................36INSTALLATION.........................36
INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION.........................36
OPERATION...........................36
REMOVAL.............................37
INSTALLATION.........................38
MAP SENSOR
DESCRIPTION.........................38
OPERATION...........................38
REMOVAL.............................39
INSTALLATION.........................40
OXYGEN SENSOR
DESCRIPTION.........................40
OPERATION...........................40
REMOVAL.............................41
INSTALLATION.........................43
THROTTLE BODY
DESCRIPTION.........................43
OPERATION...........................43
REMOVAL.............................43
INSTALLATION.........................44
THROTTLE CONTROL CABLE
REMOVAL.............................45
INSTALLATION.........................46
THROTTLE POSITION SENSOR
DESCRIPTION.........................47
OPERATION...........................47
REMOVAL.............................47
INSTALLATION.........................48
FUEL INJECTION
DESCRIPTION
The Powertrain Control Module (PCM) operates
the fuel injection system. Refer to Powertrain Control
Module in Electronic Control Modules for informa-
tion.
ACCELERATOR PEDAL
REMOVAL
The accelerator pedal is serviced as a complete
assembly including the bracket.The accelerator pedal is connected to the upper
part of the accelerator pedal arm by a plastic
retainer (clip) (Fig. 1). This plastic retainer snaps
into the top of the accelerator pedal arm.
(1) From inside the vehicle, hold up accelerator
pedal. Remove plastic cable retainer (clip) and throt-
tle cable core wire from upper end of accelerator
pedal arm (Fig. 1). Plastic cable retainer (clip) snaps
into pedal arm.
(2) Remove 2 accelerator pedal mounting bracket
nuts. Remove accelerator pedal assembly.
KJFUEL INJECTION 14 - 29

OPERATION
2.4L
Engine speed and crankshaft position are provided
through the CKP (Crankshaft Position) sensor. The
sensor generates pulses that are the input sent to the
Powertrain Control Module (PCM). The PCM inter-
prets the sensor input to determine the crankshaft
position. The PCM then uses this position, along with
other inputs, to determine injector sequence and igni-
tion timing.
The sensor is a hall effect device combined with an
internal magnet. It is also sensitive to steel within a
certain distance from it.
A tonewheel (targetwheel) is a part of the engine
crankshaft (Fig. 4). This tonewheel has sets of
notches at its outer edge.
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the input
to the PCM.
3.7L
Engine speed and crankshaft position are provided
through the CKP (Crankshaft Position) sensor. The
sensor generates pulses that are the input sent to the
Powertrain Control Module (PCM). The PCM inter-
prets the sensor input to determine the crankshaft
position. The PCM then uses this position, along with
other inputs, to determine injector sequence and igni-
tion timing.
The sensor is a hall effect device combined with an
internal magnet. It is also sensitive to steel within a
certain distance from it.A tonewheel (targetwheel) is bolted to the engine
crankshaft (Fig. 5). This tonewheel has sets of
notches at its outer edge (Fig. 5).
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the input
to the PCM.
REMOVAL
2.4L
The Crankshaft Position (CKP) sensor is mounted
into the right front side of the cylinder block (Fig. 6).
It is positioned and bolted into a machined hole.
(1) Disconnect sensor electrical connector.
(2) Remove sensor bolt.
(3) Carefully pry sensor from cylinder block in a
rocking action.
(4) Check condition of sensor o-ring (Fig. 7).
3.7L
The Crankshaft Position (CKP) sensor is mounted
into the right rear side of the cylinder block (Fig. 8).
It is positioned and bolted into a machined hole.
(1) Raise vehicle.
(2) Disconnect sensor electrical connector.
(3) Remove sensor mounting bolt (Fig. 8).
(4) Carefully remove sensor from cylinder block in
a rocking and twisting action.
(5) Check condition of sensor o-ring.
Fig. 4 CKP OPERATION-2.4L
1 - NOTCHES
2 - CRANKSHAFT
Fig. 5 CKP OPERATION-3.7L
1 - TONEWHEEL
2 - NOTCHES
3 - CRANKSHAFT POSITION SENSOR
4 - CRANKSHAFT
KJFUEL INJECTION 14 - 31
CRANKSHAFT POSITION SENSOR (Continued)

REMOVAL
(1) Remove fuel rail. Refer to Fuel Injector Rail
Removal.
(2) Disconnect clip(s) that retain fuel injector(s) to
fuel rail (Fig. 10).
INSTALLATION
(1) Install fuel injector(s) into fuel rail assembly
and install retaining clip(s).
(2) If same injector(s) is being reinstalled, install
new o-ring(s).
(3) Apply a small amount of clean engine oil to
each injector o-ring. This will aid in installation.
(4) Install fuel rail. Refer to Fuel Rail Installation.
(5) Start engine and check for fuel leaks.
FUEL PUMP RELAY
DESCRIPTION
The 5±pin, 12±volt, fuel pump relay is located in
the Power Distribution Center (PDC). Refer to the
label on the PDC cover for relay location.
OPERATION
The Powertrain Control Module (PCM) energizes
the electric fuel pump through the fuel pump relay.
The fuel pump relay is energized by first applying
battery voltage to it when the ignition key is turnedON, and then applying a ground signal to the relay
from the PCM.
Whenever the ignition key is turned ON, the elec-
tric fuel pump will operate. But, the PCM will shut-
down the ground circuit to the fuel pump relay in
approximately 1±3 seconds unless the engine is oper-
ating or the starter motor is engaged.
DIAGNOSIS AND TESTING - FUEL PUMP
RELAY
For procedures, refer to ASD Relay Diagnosis and
Testing in the Ignition section.
REMOVAL
The fuel pump relay is located in the Power Distri-
bution Center (PDC) (Fig. 11). Refer to label on PDC
cover for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.
(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The fuel pump relay is located in the Power Distri-
bution Center (PDC). Refer to label on PDC cover for
relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
Fig. 10 INJECTOR RETAINING CLIP
1 - PLIERS
2 - INJECTOR CLIP
3 - FUEL INJECTOR
4 - FUEL RAIL - TYPICAL
Fig. 11 POWER DISTRIBUTION CENTER (PDC)
1 - BATTERY
2 - PDC
3 - PDC COVER
14 - 34 FUEL INJECTIONKJ
FUEL INJECTOR (Continued)

REMOVAL
2.4L
The Idle Air Control (IAC) motor is located on the
rear side of the throttle body (Fig. 12).
(1) Disconnect electrical connector from IAC motor.
(2) Remove two mounting bolts (screws).
(3) Remove IAC motor from throttle body.
3.7L
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 13).
(1) Disconnect electrical connector from IAC motor.
(2) Remove two mounting bolts (screws).
(3) Remove IAC motor from throttle body.
INSTALLATION
2.4L
The Idle Air Control (IAC) motor is located on the
rear side of the throttle body.
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
3.7L
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 13).
(1) Install IAC motor to throttle body.(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
INTAKE AIR TEMPERATURE
SENSOR
DESCRIPTION
The 2±wire Intake Manifold Air Temperature (IAT)
sensor is installed in the intake manifold with the
sensor element extending into the air stream.
The IAT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as intake mani-
fold temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
The IAT sensor provides an input voltage to the
Powertrain Control Module (PCM) indicating the
density of the air entering the intake manifold based
upon intake manifold temperature. At key-on, a
5±volt power circuit is supplied to the sensor from
the PCM. The sensor is grounded at the PCM
through a low-noise, sensor-return circuit.
The PCM uses this input to calculate the following:
²Injector pulse-width
²Adjustment of spark timing (to help prevent
spark knock with high intake manifold air-charge
temperatures)
Fig. 12 TPS/IAC MOTOR - 2.4L
1 - THROTTLE POSITION SENSOR (TPS)
2 - MOUNTING SCREWS
3 - IDLE AIR CONTROL MOTOR (IAC)
4 - MOUNTING SCREWS
Fig. 13 TPS/IAC MOTOR - 3.7L
1 - THROTTLE POSITION SENSOR (TPS)
2 - MOUNTING SCREWS
3 - IDLE AIR CONTROL MOTOR (IAC)
4 - MOUNTING SCREWS
14 - 36 FUEL INJECTIONKJ
IDLE AIR CONTROL MOTOR (Continued)

The resistance values of the IAT sensor is the same
as for the Engine Coolant Temperature (ECT) sensor.
REMOVAL
2.4L
The intake manifold air temperature (IAT) sensor
is installed into the intake manifold plenum at the
rear end of the intake manifold (Fig. 14).
(1) Disconnect electrical connector from IAT sen-
sor.
(2) Clean dirt from intake manifold at sensor base.
(3) Gently lift on small plastic release tab (Fig. 14)
or (Fig. 15) and rotate sensor about 1/4 turn counter-
clockwise for removal.
(4) Check condition of sensor o-ring (Fig. 15).
3.7L
The intake manifold air temperature (IAT) sensor
is installed into the left side of intake manifold ple-
num (Fig. 16).
(1) Disconnect electrical connector from IAT sen-
sor.
(2) Clean dirt from intake manifold at sensor base.
(3) Gently lift on small plastic release tab (Fig. 16)
or (Fig. 15) and rotate sensor about 1/4 turn counter-
clockwise for removal.
(4) Check condition of sensor o-ring.
Fig. 14 IAT SENSOR LOCATION-2.4L
1 - RELEASE TAB
2 - IAT SENSOR
3 - PRESS HERE FOR REMOVAL
4 - ELECTRICAL CONNECTOR
5 - REAR END OF INTAKE MANIFOLD
Fig. 15 IAT SENSOR TAB / O-RING
1 - IAT SENSOR
2 - SENSOR O-RING
3 - RELEASE TAB
Fig. 16 IAT SENSOR LOCATION- 3.7L
1 - IAT SENSOR
2 - RELEASE TAB
3 - ELECTRICAL CONNECTOR
KJFUEL INJECTION 14 - 37
INTAKE AIR TEMPERATURE SENSOR (Continued)

The range of voltage output from the sensor is usually
between 4.6 volts at sea level to as low as 0.3 volts at
26 in. of Hg. Barometric pressure is the pressure
exerted by the atmosphere upon an object. At sea level
on a standard day, no storm, barometric pressure is
approximately 29.92 in Hg. For every 100 feet of alti-
tude, barometric pressure drops 0.10 in. Hg. If a storm
goes through, it can change barometric pressure from
what should be present for that altitude. You should
know what the average pressure and corresponding
barometric pressure is for your area.
REMOVAL
2.4L
The Manifold Absolute Pressure (MAP) sensor is
mounted into the rear of the intake manifold (Fig.
17). An o-ring is used to seal the sensor to the intake
manifold (Fig. 19).
(1) Disconnect electrical connector at sensor.
(2) Clean area around MAP sensor.
(3) Remove sensor mounting screw (TORX head).
(4) Remove MAP sensor from intake manifold.
(5) Check condition of sensor o-ring (Fig. 19).
3.7L
The Manifold Absolute Pressure (MAP) sensor is
mounted into the front of the intake manifold (Fig.
18). An o-ring is used to seal the sensor to the intake
manifold (Fig. 19).(1) Disconnect electrical connector at sensor.
(2) Clean area around MAP sensor.
(3) Remove 2 sensor mounting screws.
(4) Remove MAP sensor from intake manifold.
(5) Check condition of sensor o-ring (Fig. 19).
Fig. 17 MAP SENSOR LOCATION-2.4L
1 - REAR OF INTAKE MANIFOLD
2 - MAP SENSOR
3 - ALIGNMENT PIN
4 - MOUNTING BOLT (TORX)
5 - ELECTRICAL CONNECTOR
6 - MAIN ENGINE HARNESS CONNECTORS
Fig. 18 MAP SENSOR / ECT SENSOR - 3.7L
1 - MOUNTING SCREWS
2 - MAP SENSOR
3 - ECT SENSOR
Fig. 19 MAP SENSOR O-RING
1 - MAP SENSOR
2 - O-RING
KJFUEL INJECTION 14 - 39
MAP SENSOR (Continued)