2002 JEEP LIBERTY Heat

WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINE.
CAUTION: When servicing exhaust system compo-
nents, disconnect the oxygen sensor connector.
Allowing the exhaust system to hang by the oxygen
sensor harness will damage the wiring and/or sen-
sor.(1) Raise and support the vehicle.
(2) Disconnect front tailpipe hanger from the insu-
lator (Fig. 6).
(3) Remove the mounting nuts from the muffler to
catalytic converter flange (Fig. 6).
(4) Remove the tailpipe from the rear tailpipe
hanger.
(5) Remove the muffler and tailpipe assembly from
the vehicle (Fig. 6).
INSTALLATION
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are either clamped together or welded
together.
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINE.
CAUTION: When servicing exhaust system compo-
nents, disconnect the oxygen sensor connector.
Allowing the exhaust system to hang by the oxygen
sensor harness will damage the wiring and/or sen-
sor.
Fig. 4 KJ REAR HEAT SHIELD
1 - HEAT SHIELD
2 - NUT
Fig. 5 Muffler - Typical
1 - MUFFLER
Fig. 6 KJ MUFFLER AND TAILPIPE ASSEMBLY
1- TAILPIPE HANGERS
2- MUFFLER
3- FLANGE
4- NUT
KJEXHAUST SYSTEM 11s - 5
MUFFLER (Continued)

FUEL DELIVERY
DESCRIPTION
The fuel delivery system consists of:
²the 2±section fuel pump module containing the
electric fuel pump, fuel pressure regulator, fuel gauge
sending unit (fuel level sensor) and a fuel filter
located inside the lower section of pump module
²fuel tubes/lines/hoses
²A separately mounted main fuel filter²quick-connect fittings
²fuel injector rail
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
Certain fuel delivery components can be found in
(Fig. 1).
Fig. 1 FUEL DELIVERY COMPONENTS
1 - FUEL TANK 10 - EVAP CANISTER
2 - FUEL TANK STRAPS 11 - FLOW MANAGEMENT VALVE
3 - FUEL PUMP MODULE LOCK RING 12 - FRESH AIR TUBE
4 - CHECK (CONTROL) VALVE 13 - HOSE SLEEVE
5 - FUEL PUMP MODULE FLANGE 14 - FUEL FILTER
6 - FUEL FILL HOSE 15 - LEAK DETECTION PUMP
7 - FRESH AIR FILTER 16 - HEAT SHIELD
8 - FUEL FILL CAP/BEZEL 17 - SKID PLATE
9 - FUEL FILL TUBE
14 - 2 FUEL DELIVERYKJ

SPECIFICATIONS
FUEL SYSTEM PRESSURE
339 kPa +/- 34 kPa (49.2 psi +/- 2 psi).
TORQUE
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Accelerator Pedal Bracket Mounting Nuts 12 - 105
Crankshaft Position Sensor - 2.4L 28 21 -
Crankshaft Position Sensor - 3.7L 28 21 -
Camshaft Position Sensor - 2.4L 12 - 106
Camshaft Position Sensor - 3.7L 12 - 106
Engine Coolant Temperature Sensor 11 - 96
EVAP Canister-to-Body Bolts 48 35 -
EVAP Canister-to-Canis. Bracket Bolt/Nut 11 - 100
Fuel Filler Hose Clamp at Tank 3 - 30
Fuel Filler Housing-to-Body Screws 2 - 17
Fuel Filter Mounting Nut at Tank 5.5 - 49
Fuel Pump Module Access Plate Nuts 3 - 26
Fuel Rail Mounting Bolts - 3.7L 11 - 100
Fuel Rail Mounting Bolts - 2.4L 28 - 250
Fuel Tank Heat Sheild Nuts 5.5 - 49
Fuel Tank Mounting Strap Bolts 61 45 -
Fuel Tank Skid Plate and Trailer Hitch 88 65 -
IAC Motor Mounting Screws 7 - 60
Leak Detection Pump Mounting Bracket-to-Fuel
Tank Nuts5.5 - 49
Leak Detection Pump-to-Bracket Nuts 1.2 - 11
Map Sensor Mounting Screws 3 - 25
PCM-to-Mounting Bracket Mounting Screws 4 - 35
Power Steering Pressure Switch 14-22 - 124-195
TPS Mounting Screws 7 - 60
Throttle Body Mounting Bolts 11 - 100
Oxygen Sensors 30 22 -
KJFUEL DELIVERY 14 - 5
FUEL DELIVERY (Continued)

(3) Remove 4 fuel pump module access plate nuts
(Fig. 3).
(4) While applying heat from a heat gun, carefully
pry up fuel pump module access plate. Take care not
to bend plate.
(5) Disconnect flow management valve hose clamp
and hose (Fig. 4) at pump module fitting. Also discon-
nect small recirculation line at top half of manage-
ment valve.
(6) Raise vehicle.
(7) Disconnect opposite end of flow management
valve hose at EVAP canister (Fig. 1).
(8) Remove valve and 2 hoses as an assembly.
INSTALLATION
(1) Raise vehicle.
(2) Attach 2 large hoses and 1 small line to flow
management valve. Position this assembly to top of
fuel tank.
(3) Connect valve hose at EVAP canister.
(4) Lower vehicle.
(5) Attach valve hose and clamp to top of fuel
pump module.
(6) Apply silicone sealant to bottom of fuel pump
module metal access plate.(7) Install fuel pump module metal access plate
and 4 nuts. Tighten nuts to 3 N´m (26 in. lbs.)
torque.
(8) Position carpet and install 2 new cargo clamp
rivets.
FUEL FILTER
DESCRIPTION
The fuel pressure regulator and fuel filter are not
combined on this vehicle. The main fuel filter is
attached to the front of the fuel tank (Fig. 1) and is a
serviceable/replaceable item. Also refer to Inlet Filter
and Fuel Pressure Regulator.
REMOVAL
The main fuel filter is attached to the front of fuel
tank (Fig. 1). Three fuel lines are used at filter.
Fuel tank removal will not be necessary for
fuel filter removal. Access is from rear cargo
area.
WARNING: THE FUEL SYSTEM MAY BE UNDER A
CONSTANT PRESSURE (EVEN WITH THE ENGINE
OFF). BEFORE SERVICING MOST FUEL SYSTEM
COMPONENTS, THE FUEL SYSTEM PRESSURE
MUST BE RELEASED. REFER TO THE FUEL SYS-
TEM PRESSURE RELEASE PROCEDURE.
(1) Release fuel system pressure.
(2) Four cargo holdown clamps are located inside
vehicle on floor of rear cargo area. Two of these four
clamps must be removed. Remove 2 rearward
mounted clamps by drilling out clamp rivets.
(3) Fold carpeting forward to gain access to fuel
pump module access plate (Fig. 5).
(4) Remove 4 fuel pump module access plate nuts
(Fig. 5).
(5) While applying heat from a heat gun, carefully
pry up metal fuel pump module access plate. Take
care not to bend plate.
(6) Clean top of fuel pump module area around
fuel line connection points.
(7) Disconnect 2 fuel lines at fuel pump module
(Fig. 6) by pressing on tabs at side of fitting.
(8) Raise vehicle.
(9) Place drain pan under fuel filter.
(10) A third fuel line is attached to bottom of filter
(Fig. 7). The disconnection point for this 3rd line is
approximately 1 foot towards front of vehicle. Clean
fuel line connection point before disconnection. Dis-
connect by pressing on tabs at side of fitting.
(11) Disconnect 3rd fuel line from body retention
clip. Place a small screwdriver into side of clip and
twist for removal.
Fig. 4 TOP OF FUEL PUMP MODULE
1 - LOCK RING
2 - ALIGNMENT NOTCH
3 - FUEL FILTER FITTINGS (2)
4 - ORVR SYSTEM HOSE AND CLAMP
5 - FLOW MANAGEMENT VALVE
6 - ELECTRICAL CONNECTOR
7 - LEAK DETECTION PUMP
8 - FUEL TANK CHECK (CONTROL) VALVE
9 - FUEL PUMP MODULE (UPPER SECTION)
KJFUEL DELIVERY 14 - 7
FLOW MANAGEMENT VALVE (Continued)

(17) When LCS adapter test leads are attached
into relay cavities, fuel pumpwill be activated.
Determine fuel pump amperage on DRB screen.
Amperage should be below 10.0 amps. If amperage is
below 10.0 amps, and specifications for the Fuel
Pump Pressure, Fuel Pump Capacity and Fuel Pres-
sure Leak Down tests were met, the fuel pump mod-
ule is OK.
(18) If amperage is more than 10.0 amps, replace
fuel pump module assembly. The electric fuel pump
is not serviced separately.
(19) Disconnect test leads from relay cavities
immediately after testing.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module assembly is located in the
fuel tank (Fig. 1). The assembly is divided into 2±sec-
tions, upper and lower. The lower section is locked to
the bottom of the fuel tank. The complete assembly
contains the following components:
²A fuel pressure regulator
²A separate fuel pick-up, or inlet filter
²An electric fuel pump
²A lockring to retain upper section of pump mod-
ule to tank
²A rollover valve
²A vent fitting for ORVR system
²A soft gasket between tank flange and module
²A fuel gauge sending unit (fuel level sensor)
²Two fuel line connections (supply and return)
The fuel gauge sending unit may be serviced sepa-
rately. If the electrical fuel pump, primary inlet filter
or fuel pressure regulator require service, the lower
section of the fuel pump module must be replaced.
OPERATION
Refer to Fuel Pump, Inlet Filter, Fuel Pressure
Regulator and Fuel Gauge Sending Unit.
REMOVAL
The fuel pump module is divided into 2 sections,
upper and lower. To service the check (control) valve,
replace only the upper section. To service the fuel
gauge sending unit, remove the upper section. To ser-
vice the electric fuel pump, fuel pressure regulator or
primary inlet filter, remove both sections and replace
lower section.
Fuel tank removal will not be necessary for
fuel pump module removal. Access is from rear
cargo area.
(1) Four cargo holdown clamps are located inside
the vehicle on the floor of the rear cargo area.Remove the 2 rearward mounted clamps by drilling
out the clamp rivets.
(2) Fold carpeting forward to gain access to fuel
pump module access plate (Fig. 25).
(3) Remove 4 fuel pump module access plate nuts
(Fig. 25).
(4) While applying heat from a heat gun, carefully
pry up fuel pump module access plate. Take care not
to bend plate.
(5) Thoroughly clean area around top of pump
module to prevent contaminants from entering fuel
tank or fuel lines.
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE EVEN WITH ENGINE OFF.
BEFORE SERVICING THE FUEL PUMP MODULE,
FUEL SYSTEM PRESSURE MUST BE RELEASED.
(6) Release fuel system pressure. Refer to Fuel
System Pressure Release procedure.
(7) Disconnect 2 fuel lines at fuel pump module
(Fig. 26) by pressing on 2 buttons at sides of fitting.
(8) Disconnect electrical connector (Fig. 26) at top
of fuel pump module by sliding red colored tab first
to unlock, and push grey colored tab down for
removal.
(9) Disconnect ORVR hose clamp and hose (Fig.
26) at pump module fitting.
(10) Remove module lockring (Fig. 26) using a
brass drift and hammer (counter-clockwise).
(11) Carefully lift upper section of pump module
(Fig. 26) from fuel tank exposing connections(lift
upper section from tank very slowly until rub-
ber gasket can be retained. If not, gasket will
fall into fuel tank.)
(a) Disconnect electrical connector (Fig. 27) at
bottom of upper pump module section.
(b) Disconnect fuel pressure regulator (Fig. 27)
at bottom of upper pump module section. Press on
2 locking tabs.
(c) Disconnect fuel return line (Fig. 27) at bot-
tom of upper pump module section. Press on 2
locking tabs.
(d) Remove upper section of pump module (Fig.
28) from fuel tank.
(12) Using an approved gas holding tank, drain
fuel tank through pump module opening.If check
(control) valve, or, only upper section of pump
module is being serviced, tank draining is not
necessary. If any other fuel pump module com-
ponent is being serviced, the tank must be com-
pletely drained to the bottom.
(13) To remove lower section of pump module from
fuel tank:
(a) Using finger pressure, push on plastic
release tab (Fig. 29) while sliding lock tab upward.
14 - 18 FUEL DELIVERYKJ
FUEL PUMP (Continued)

REMOVAL
Fuel Tank Draining
WARNING: THE FUEL SYSTEM MAY BE UNDER
CONSTANT FUEL PRESSURE EVEN WITH THE
ENGINE OFF. THIS PRESSURE MUST BE
RELEASED BEFORE SERVICING FUEL TANK.
Two different procedures may be used to drain fuel
tank: removing fuel pump module access plate, or
using DRBtscan tool. Due to a one-way check valve
installed into the fuel fill opening fitting at the tank
(Fig. 38), the tank cannot be drained conventionally
at the fill cap.
The quickest draining procedure involves removing
fuel pump module access plate.
As an alternative procedure, the electric fuel pump
may be activated allowing tank to be drained at fuel
rail connection. Refer to DRB scan tool for fuel pump
activation procedures. Before disconnecting fuel line
at fuel rail, release fuel pressure. Refer to the Fuel
System Pressure Release Procedure for procedures.
Attach end of special test hose tool number 6541,
6539, 6631 or 6923 at fuel rail disconnection (tool
number will depend on model and/or engine applica-
tion). Position opposite end of this hose tool to an
approved gasoline draining station. Activate fuel
pump and drain tank until empty.
If electric fuel pump is not operating, fuel pump
module access plate must be removed for fuel drain-
ing. Refer to following procedures.Fuel tank removal will not be necessary for
fuel tank draining. Access for draining is from
rear cargo area.
(1) Open all windows in vehicle to allow for air
ventilation.
(2) Four cargo holdown clamps are located inside
the vehicle on the floor of the rear cargo area.
Remove the 2 rearward mounted clamps by drilling
out the clamp rivets.
(3) Fold carpeting forward to gain access to fuel
pump module access plate (Fig. 39).
(4) Remove 4 fuel pump module access plate nuts
(Fig. 39).
(5) While applying heat from a heat gun, carefully
pry up fuel pump module access plate. Take care not
to bend plate.
(6) Thoroughly clean area around top of pump
module to prevent contaminants from entering fuel
tank or fuel lines.
(7) Release fuel system pressure.
(8) Disconnect 2 fuel lines (Fig. 40) at fuel pump
module by pressing on tabs at side of fitting.
(9) Disconnect electrical connector (Fig. 40). Slide
red tab first to unlock, and push grey tab down for
removal.
(10) Disconnect ORVR hose (Fig. 40) at pump mod-
ule fitting.
Fig. 38 FUEL FILL CHECK VALVE
1 - ONE-WAY CHECK VALVE
2 - FUEL FILL FITTING
3 - SIDE OF FUEL TANK
Fig. 39 ACCESS PLATE
1 - FLOORPAN AT REAR
2 - FUEL PUMP MODULE ACCESS PLATE
3 - NUTS (4)
4 - OPENING TO PUMP MODULE
KJFUEL DELIVERY 14 - 25
FUEL TANK (Continued)

INSTALLATION
2.4L
The Manifold Absolute Pressure (MAP) sensor is
mounted into the rear of the intake manifold. An
o-ring is used to seal the sensor to the intake mani-
fold (Fig. 19).
(1) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.
(4) Install MAP sensor mounting screws. Tighten
screw to 3 N´m (25 in. lbs.) torque.
(5) Connect electrical connector.
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) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.
(4) Install MAP sensor mounting bolts (screws).
Tighten screws to 3 N´m (25 in. lbs.) torque.
(5) Connect electrical connector.
OXYGEN SENSOR
DESCRIPTION
The Oxygen Sensors (O2S) are attached to, and
protrude into the vehicle exhaust system. Depending
on the engine or emission package, the vehicle may
use a total of either 2 or 4 sensors.
2.4L Engine:Two sensors are used: upstream
(referred to as 1/1) and downstream (referred to as
1/2). With this emission package, the upstream sen-
sor (1/1) is located just before the main catalytic con-
vertor. The downstream sensor (1/2) is located just
after the main catalytic convertor.
3.7L V-6 Engine:On this emissions package, 4
sensors are used: 2 upstream (referred to as 1/1 and
2/1) and 2 downstream (referred to as 1/2 and 2/2).
With this emission package, the right upstream sen-
sor (2/1) is located in the right exhaust downpipe just
before the mini-catalytic convertor. The left upstream
sensor (1/1) is located in the left exhaust downpipe
just before the mini-catalytic convertor. The right
downstream sensor (2/2) is located in the right
exhaust downpipe just after the mini-catalytic con-
vertor, and before the main catalytic convertor. The
left downstream sensor (1/2) is located in the left
exhaust downpipe just after the mini-catalytic con-
vertor, and before the main catalytic convertor.
OPERATION
An O2 sensor is a galvanic battery that provides
the PCM with a voltage signal (0-1 volt) inversely
proportional to the amount of oxygen in the exhaust.
In other words, if the oxygen content is low, the volt-
age output is high; if the oxygen content is high the
output voltage is low. The PCM uses this information
to adjust injector pulse-width to achieve the
14.7±to±1 air/fuel ratio necessary for proper engine
operation and to control emissions.
The O2 sensor must have a source of oxygen from
outside of the exhaust stream for comparison. Cur-
rent O2 sensors receive their fresh oxygen (outside
air) supply through the O2 sensor case housing.
Four wires (circuits) are used on each O2 sensor: a
12±volt feed circuit for the sensor heating element; a
ground circuit for the heater element; a low-noise
sensor return circuit to the PCM, and an input cir-
cuit from the sensor back to the PCM to detect sen-
sor operation.
Oxygen Sensor Heater Relay - 3.7L Engine:On
the 3.7L engine, 4 heated oxygen sensors are used. A
separate oxygen sensor relay is used to supply volt-
age to the sensors heating elements for only the 1/2
and 2/2 downstream sensors. Voltage for the other 2
sensor heating elements is supplied directly from the
Powertrain Control Module (PCM) through a Pulse
Width Module (PWM) method.
Pulse Width Module (PWM):Voltage to the O2
sensor heating elements is supplied directly from the
Powertrain Control Module (PCM) through two sepa-
rate Pulse Width Module (PWM) low side drivers.
PWM is used on both the upstream and downstream
O2 sensors on the 2.4L engine, and only on the 2
upstream sensors (1/1 and 2/1) on the 3.7L engine.
The main objective for a PWM driver is to avoid over-
heating of the O2 sensor heater element. With
exhaust temperatures increasing with time and
engine speed, it's not required to have a full-voltage
duty-cycle on the O2 heater elements.
To avoid the large simultaneous current surge
needed to operate all 4 sensors, power is delayed to
the 2 downstream heater elements by the PCM for
approximately 2 seconds.
Oxygen Sensor Heater Elements:
The O2 sensor uses a Positive Thermal Co-efficient
(PTC) heater element. As temperature increases,
resistance increases. At ambient temperatures
around 70ÉF, the resistance of the heating element is
approximately 4.5 ohms. As the sensor's temperature
increases, resistance in the heater element increases.
This allows the heater to maintain the optimum
operating temperature of approximately 930É-1100ÉF
(500É-600É C). Although the sensors operate the
same, there are physical differences, due to the envi-
14 - 40 FUEL INJECTIONKJ
MAP SENSOR (Continued)

THROTTLE CONTROL CABLE
REMOVAL
2.4L
CAUTION: Be careful not to damage or kink the
cable core wire (within the cable sheathing) while
servicing accelerator pedal or throttle cable.
(1) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer (clip) and throttle cable
core wire from upper end of pedal arm (Fig. 26).
Plastic cable retainer snaps into top of pedal arm.
(2) Remove cable core wire at pedal arm.
(3) From inside vehicle, remove metal clip holding
cable to dashpanel (Fig. 26).
(4) Remove air box at throttle body.
(5) Unsnap cable from dashpanel routing clip.
(6) Remove cable housing from dash panel and
pull into engine compartment.
(7) Hold throttle in wide open position. While held
in this position, slide throttle cable pin (Fig. 27) from
throttle body bellcrank.(8) Using a pick or small screwdriver, press release
tab (Fig. 27) to release plastic cable mount from
bracket.Press on tab only enough to release
cable from bracket. If tab is pressed too much,
it will be broken.To remove throttle cable from
throttle body bracket, slide cable towards front of
vehicle.
(9) Remove throttle cable from vehicle.
3.7L
CAUTION: Be careful not to damage or kink the
cable core wire (within the cable sheathing) while
servicing accelerator pedal or throttle cable.
(1) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer (clip) and throttle cable
core wire from upper end of pedal arm (Fig. 28).
Plastic cable retainer snaps into top of pedal arm.
(2) Remove cable core wire at pedal arm.
(3) From inside vehicle, remove metal clip holding
cable to dashpanel (Fig. 28).
(4) Remove air box at throttle body.
(5) Unsnap cable from dashpanel routing clip.
(6) Remove cable housing from dash panel and
pull into engine compartment.
(7) Hold throttle in wide open position. While held
in this position, slide throttle cable pin (Fig. 29) from
throttle body bellcrank.
Fig. 26 ACCELERATOR PEDAL/BRACKET
ASSEMBLY
1 - METAL THROTTLE CABLE CLIP
2 - THROTTLE CABLE
3 - PLASTIC CABLE RETAINER
4 - PEDAL/BRACKET ASSEMBLY
5 - PEDAL MOUNTING NUTS (2)
6 - PEDAL MOUNTING STUDS (2)
Fig. 27 THROTTLE CABLE, PIN, RELEASE TAB-2.4L
1 - MOUNTING BRACKET
2 - SPEED CONTROL CABLE
3 - THROTTLE CABLE
4 - RELEASE TAB
5 - CABLE PINS
6 - BELLCRANK
KJFUEL INJECTION 14 - 45