Electrical JEEP LIBERTY 2002 KJ / 1.G Workshop Manual
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Page 1345 of 1803

(3) Screw oil filter on until the gasket contacts
base. Tighten to 21 N´m (15 ft. lbs.).
OIL PAN
REMOVAL
(1) Remove air cleaner assembly.
(2) Raise vehicle on hoist and drain engine oil.
(3) Loosen the engine mount thru bolts.
(4) Disconnect exhaust pipe at manifold.
(5) Remove structural collar, if equipped.
(6) Remove front axle mounting bolts, and lower
axle as far possible, if equipped.
(7) Using suitable jack, raise engine as needed.
(8) Remove oil pan attaching bolts.
(9) Remove oil pan.
(10) Clean oil pan and all gasket surfaces.
INSTALLATION
(1) Install the oil pan gasket to the block.
(2) Apply a 3MM (1/8 inch) bead of MopartEngine
RTV at the oil pump to engine block parting line
(Fig. 80).
(3) Install pan and tighten the screws to 12 N´m
(105 in. lbs.).
(4) Lower engine, and remove jack.
(5) Tighten engine mount thru bolts.
(6) Raise the front axle into position, and reinstall
front axle mounting bolts. If equipped.
(7) Reconnect exhaust pipe to manifold.
(8) Install structural collar, if equipped.
(9) Lower vehicle.(10) Fill engine crankcase with proper oil to cor-
rect level.
(11) Reinstall air cleaner assembly.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, electrical/mechanical engine oil pres-
sure sensor (sending unit) is located in an engine oil
pressure gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
Fig. 79 2.4 OIL FILTERFig. 80 OIL PAN GASKET INSTALLATION
1 - SEALER LOCATION
9s - 48 ENGINEKJ
OIL FILTER (Continued)
Page 1349 of 1803

(2) Spray a small stream of water (Spray Bottle) at
the suspected leak area.
(3) If engine RPM'S change, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect connector from inlet air tempera-
ture sensor.
(3) Disconnect air intake tube at throttle body and
remove upper air cleaner housing.
(4) Disconnect connector from throttle position
sensor (TPS).
(5) Disconnect connector from idle air control (IAC)
motor.
(6) Disconnect connector from MAP sensor.
(7) Remove vacuum lines for purge solenoid and
PCV valve at intake manifold.
(8) Remove vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at intake manifold fittings.
(9) Disconnect throttle, speed control (if equipped),
and transaxle control (if equipped) and cables from
throttle lever and bracket. (Refer to 14 - FUEL SYS-
TEM/FUEL INJECTION/THROTTLE CONTROL
CABLE - REMOVAL)
(10) Perform fuel system pressure release proce-
durebefore attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)
(11) Disconnect fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(12) Disconnect coolant temperature sensor/fuel
injector wire harness connector.
(13) Disconnect fuel injector harness.
(14) Remove intake manifold to cylinder head fas-
teners.
(15) Remove the manifold from engine.
CAUTION: Cover intake manifold openings to pre-
vent foreign material from entering engine.
(16) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSPECTION)
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
(1) Clean manifold sealing surfaces.
(2) Install new manifold to cylinder head seals.
(3) Install manifold to head.
(4) Install and tighten intake manifold fasteners to
28 N´m (250 in. lbs.) in the sequence shown (Fig. 90).
Repeat procedure until all bolts are at specified
torque.
(5) Install throttle cables in bracket.
(6) Connect throttle, speed control, (if equipped),
cables to throttle lever.
(7) Connect vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(8) Connect vacuum lines for purge solenoid and
PCV valve.
(9) Connect electrical connectors for MAP sensor,
throttle position sensor (TPS), and idle air control
(IAC) motor.
(10) Connect the fuel line. (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(11) Connect coolant temperature sensor/fuel injec-
tor wiring harness electrical connector.
(12) Install the air cleaner housing and air intake
tube to throttle body.
(13) Connect inlet air temperature sensor connec-
tor.
(14) Connect negative cable to battery.
Fig. 90 LOWER INTAKE MANIFOLD TIGHTENING
SEQUENCE
9s - 52 ENGINEKJ
INTAKE MANIFOLD (Continued)
Page 1374 of 1803

FRAMES & BUMPERS
TABLE OF CONTENTS
page page
FRONT FASCIA
REMOVAL.............................1
INSTALLATION..........................2
REAR FASCIA
REMOVAL.............................2
INSTALLATION..........................2
REAR FASCIA SUPPORT
REMOVAL.............................3
INSTALLATION..........................3
FRAME
SPECIFICATIONS
SPECIFICATIONS - FRAME DIMENSIONS . . . 3
SPECIFICATIONS - TORQUE.............6
FRONT SKID PLATE
REMOVAL.............................6
INSTALLATION..........................6
ENGINE CRADLE CROSSMEMBER
REMOVAL.............................6
INSTALLATION..........................6TRANSFER CASE SKID PLATE
REMOVAL.............................7
INSTALLATION..........................7
REAR CROSSMEMBER
REMOVAL.............................7
INSTALLATION..........................7
FRONT TOW HOOK
REMOVAL.............................8
INSTALLATION..........................8
REAR TOW HOOK
REMOVAL.............................8
INSTALLATION..........................8
TRAILER HITCH
REMOVAL.............................9
INSTALLATION..........................9
FUEL TANK SKID PLATE
REMOVAL.............................9
INSTALLATION..........................9
FRONT FASCIA
REMOVAL
(1) Remove the grille. (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL)
(2) Raise and support vehicle.
(3) Remove the front wheel opening flare moldings.
(Refer to 23 - BODY/EXTERIOR/FRONT WHEEL
OPENING FLARE MOLDINGS - REMOVAL)
(4) Remove the four screws through the lower air
dam (Fig. 1).
(5) Disconnect the electrical connectors:
²Fascia to grille opening reinforcement. (Fig. 1)
²Side repeater lights, both sides, if equipped.
(Fig. 2)
(6) Remove the six push pins from the grill sup-
port.
(7) Remove the rivets attaching the air dam to the
wheelhouse splash shield.
(8) Release the support tabs beneath the head-
lamps.
(9) Release the inner support clips from within the
fascia between the lights (Fig. 2).
(10) Remove the fascia.
Fig. 1 FRONT FASCIA
1 - ELECTRICAL CONNECTOR
2 - PUSH PINS
3 - FRONT FASCIA ASSEMBLY
4 - LOWER SCREWS
5 - PLASTIC RIVETS (2)
6 - INNER SUPPORT CLIPS
7 - SUPPORT TABS
KJFRAMES & BUMPERS 13 - 1
Page 1375 of 1803

INSTALLATION
(1) Install the fascia.
(2) Connect the electrical connectors.
²Side repeater lights, both sides, if equipped.
²Fascia to grille opening reinforcement.
(3) Install the six push pin fasteners into the grill
support.
(4) Install the four screws through the lower air
damn.
(5) Install new rivets attaching the air dam to the
wheelhouse splash shield.
(6) Install the front wheel opening flare moldings.
(Refer to 23 - BODY/EXTERIOR/WHEEL OPENING
FLARE MOLDING - INSTALLATION)
(7) Install the grille. (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION)
REAR FASCIA
REMOVAL
(1) Remove the wheel flares (rear). (Refer to 23 -
BODY/EXTERIOR/REAR WHEEL OPENING
FLARE MOLDINGS - REMOVAL)
(2) Remove the rear lamp units. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
REAR LAMP UNIT - REMOVAL)(3) Remove the four side bolts. (Fig. 3)
(4) Remove the four bottom rivets.
(5) Remove the 3 bolts along the upper edge.
(6) Separate the side plastic retainers and remove
the fascia from the vehicle.
INSTALLATION
NOTE: Fascia must be pushed completely forward
to allow the plastic retainers full engagement in
their respective slots.
(1) Install the fascia and insert the plastic retain-
ers.
(2) Install the three upper bolts.
(3) Install the four side bolts.
(4) Install four bottom rivets.
(5) Install the rear lamp units. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/REAR
LAMP UNIT - INSTALLATION)
(6) Install the rear half wheel opening flares.
(Refer to 23 - BODY/EXTERIOR/WHEEL OPENING
FLARE MOLDING - INSTALLATION)
Fig. 2 FASCIA INNER SUPPORT
1 - INNER SUPPORT CLIP
2 - SIDE REPEATER CONNECTOR (IF EQUIPPED)
3 - FASCIA ASSEMBLY
4 - FOG LAMP
Fig. 3 REAR FASCIA
1 - REAR FASCIA ASSEMBLY
2 - PLASTIC RETAINERS
3 - FASCIA SUPPORT BRACKET
4 - SIDE BOLTS
5 - RIVETS
6 - UPPER BOLTS
13 - 2 FRAMES & BUMPERSKJ
FRONT FASCIA (Continued)
Page 1382 of 1803

TRAILER HITCH
REMOVAL
(1) Remove the tow hooks, if equipped. (Refer to 13
- FRAME & BUMPERS/FRAME/REAR TOW HOOK
- REMOVAL)
(2) Disconnect trailer electrical connector.
(3) Support the hitch with a suitable lifting device.
(4) Remove the bolts and remove the trailer hitch.
(Fig. 12)
INSTALLATION
(1) Support the hitch with a suitable lifting device
and install the hitch.
(2) Install the bolts and tighten to 88 N´m (65 ft.
lbs.)
(3) Connect the electrical connector.
FUEL TANK SKID PLATE
REMOVAL
(1) Raise and support the vehicle.
(2) Support the skid plate with a suitable lifting
device.
(3) Remove the trailer hitch, if equipped. (Refer to
13 - FRAME & BUMPERS/FRAME/TRAILER
HITCH - REMOVAL)
(4) Remove the tow hooks, if not previously
removed. (Refer to 13 - FRAME & BUMPERS/
FRAME/REAR TOW HOOK - REMOVAL)
(5) Remove the bolts and remove the fuel tank
skid plate.
INSTALLATION
(1) Install the skid plate and support with a suit-
able lifting device.(2) Install the trailer hitch, if equipped. (Refer to
13 - FRAME & BUMPERS/FRAME/TRAILER
HITCH - INSTALLATION)
(3) Install the tow hooks, if equipped. (Refer to 13
- FRAME & BUMPERS/FRAME/REAR TOW HOOK
- INSTALLATION)
(4) Install the bolts and tighten to 88 N´m (65 ft.
lbs.).
Fig. 12 TRAILER HITCH
1 - BOLTS
2 - TRAILER LIGHTS ELECTRICAL CONNECTOR
3 - TRAILER HITCH
KJFRAMES & BUMPERS 13 - 9
Page 1389 of 1803

(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)
Page 1391 of 1803

FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel pump module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel pump module has 4 different circuits
(wires). Two of these circuits are used for the fuel
gauge sending unit for fuel gauge operation, and for
certain OBD II emission requirements. The other 2
wires are used for electric fuel pump operation.
For Fuel Gauge Operation:A constant current
source of approximately 32 milliamps is supplied to
the resistor track on the fuel gauge sending unit.
This is fed directly from the Powertrain Control Mod-
ule (PCM).NOTE: For diagnostic purposes, this
12V power source can only be verified with the
circuit opened (fuel pump module electrical
connector unplugged). With the connectors
plugged, output voltages will vary from about
0.6 volts at FULL, to about 8.6 volts at EMPTY
(about 8.6 volts at EMPTY for Jeep models, and
about 7.0 volts at EMPTY for Dodge Truck mod-
els).The resistor track is used to vary the voltage
(resistance) depending on fuel tank float level. As
fuel level increases, the float and arm move up,
which decreases voltage. As fuel level decreases, the
float and arm move down, which increases voltage.
The varied voltage signal is returned back to the
PCM through the sensor return circuit.
Both of the electrical circuits between the fuel
gauge sending unit and the PCM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the PCM, the PCM
will interpret the resistance (voltage) data and send
a message across the multi-plex bus circuits to the
instrument panel cluster. Here it is translated into
the appropriate fuel gauge level reading. Refer to
Instrument Panel for additional information.
For OBD II Emission Monitor Requirements:
The PCM will monitor the voltage output sent from
the resistor track on the sending unit to indicate fuel
level. The purpose of this feature is to prevent the
OBD II system from recording/setting false misfire
and fuel system monitor diagnostic trouble codes.
The feature is activated if the fuel level in the tank
is less than approximately 15 percent of its rated
capacity. If equipped with a Leak Detection Pump
(EVAP system monitor), this feature will also be acti-
vated if the fuel level in the tank is more than
approximately 85 percent of its rated capacity.
DIAGNOSIS AND TESTING - FUEL LEVEL
SENDING UNIT
The fuel level sending unit contains a variable
resistor (track). As the float moves up or down, elec-
trical resistance will change. Refer to Instrument
Panel and Gauges for Fuel Gauge testing. To test the
gauge sending unit only, it must be removed from
vehicle. The unit is a separate part of the lower fuel
pump module section. Refer to Fuel Pump Module
Removal/Installation for procedures (remove only the
upper section of the fuel pump module). Measure the
resistance across the sending unit terminals. With
float in up position, resistance should be 20 ohms (+/-
5%). With float in down position, resistance should be
270 ohms (+/- 5%).
REMOVAL
The fuel level sending unit (fuel level sensor) and
float assembly is located on the side of the lower sec-
tion of the fuel pump module. The lower section of
the fuel pump module is located within the fuel tank.
(1) Remove lower section of fuel pump module
from fuel tank. Refer to Fuel Pump Module Removal/
Installation.
(2) To remove sending unit from pump module, lift
on plastic locking tab (Fig. 8) while sliding sending
unit upwards.
(3) Disconnect 4±wire electrical connector (Fig. 9)
from bottom of upper section of fuel pump module.
Separate necessary sending unit wiring.
Fig. 8 FUEL LEVEL SENDING UNIT
1 - LIFT TAB HERE FOR REMOVAL
2 - FUEL LEVEL SENDING UNIT
3 - LOWER SECTION OF PUMP MODULE
KJFUEL DELIVERY 14 - 9
Page 1392 of 1803

INSTALLATION
(1) Connect necessary wiring into electrical con-
nectors. Connect 4±wire connector to upper section of
pump module.
(2) Position sending unit to pump module. Slide
and snap into place.
(3) Install lower section of fuel pump module.
Refer to Fuel Pump Module Removal/Installation.
FUEL LINES
DESCRIPTION
Also refer to Quick-Connect Fittings.
WARNING: THE FUEL SYSTEM MAY BE UNDER A
CONSTANT PRESSURE (EVEN WITH THE ENGINE
OFF). BEFORE SERVICING ANY FUEL SYSTEM
HOSES, FITTINGS, LINES, OR MOST COMPO-
NENTS, FUEL SYSTEM PRESSURE MUST BE
RELEASED. REFER TO THE FUEL SYSTEM PRES-
SURE RELEASE PROCEDURE.
The lines/tubes/hoses used on fuel injected vehicles
are of a special construction. This is due to the
higher fuel pressures and the possibility of contami-nated fuel in this system. If it is necessary to replace
these lines/tubes/hoses, only those marked EFM/EFI
may be used.
If equipped:The hose clamps used to secure rub-
ber hoses on fuel injected vehicles are of a special
rolled edge construction. This construction is used to
prevent the edge of the clamp from cutting into the
hose. Only these rolled edge type clamps may be
used in this system. All other types of clamps may
cut into the hoses and cause high-pressure fuel leaks.
Use new original equipment type hose clamps.
QUICK CONNECT FITTING
DESCRIPTION
Different types of quick-connect fittings are used to
attach various fuel system components, lines and
tubes. These are: a single-tab type, a two-tab type or
a plastic retainer ring type. Some are equipped with
safety latch clips. Some may require the use of a spe-
cial tool for disconnection and removal. Refer to
Quick-Connect Fittings Removal/Installation for more
information.
CAUTION: The interior components (o-rings, clips)
of quick-connect fittings are not serviced sepa-
rately, but new plastic spacers are available for
some types. If service parts are not available, do
not attempt to repair the damaged fitting or fuel line
(tube). If repair is necessary, replace the complete
fuel line (tube) assembly.
STANDARD PROCEDURE - QUICK-CONNECT
FITTINGS
Also refer to Fuel Tubes/Lines/Hoses and Clamps.
Different types of quick-connect fittings are used to
attach various fuel system components, lines and
tubes. These are: a single-tab type, a two-tab type or
a plastic retainer ring type. Safety latch clips are
used on certain components/lines. Certain fittings
may require use of a special tool for disconnection.
DISCONNECTING
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH ENGINE OFF).
BEFORE SERVICING ANY FUEL SYSTEM HOSE,
FITTING OR LINE, FUEL SYSTEM PRESSURE MUST
BE RELEASED. REFER TO FUEL SYSTEM PRES-
SURE RELEASE PROCEDURE.
Fig. 9 FUEL PRESSURE REGULATOR/SENDING
UNIT ELECTRICAL CONNECTOR
1 - UPPER SECTION OF PUMP MODULE
2 - QUICK-CONNECT FITTINGS
3 - FUEL PRESSURE REGULATOR
4 - 4-WIRE ELECTRICAL CONNECTOR
5 - FUEL TANK CHECK (CONTROL) VALVE
14 - 10 FUEL DELIVERYKJ
FUEL LEVEL SENDING UNIT / SENSOR (Continued)
Page 1396 of 1803

OPERATION
The fuel pressure regulator is a mechanical device
that is not controlled by engine vacuum or the Pow-
ertrain Control Module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa +/- 34
kPa (49.2 psi +/- 5 psi) at the fuel injectors. It con-
tains a diaphragm, calibrated springs and a fuel
return valve.
The main fuel filteris not combinedwithin the
fuel pressure regulator as in other Jeeptmodels.
Three different fuel filters are used: 1. a serviceable,
separate, externally mounted, main fuel filter; 2. a
non-serviceable primary filter located on the bottom
of the electric fuel pump; 3. a non-serviceable second-
ary filter attached to the side of the fuel pump mod-
ule.
Fuel Flow:Fuel migrates into the fuel pump mod-
ule reservoir through a one-way check valve located
on the bottom of the module. This check valve pre-
vents the reservoir from running empty such as
when going up or down hills with a low amount of
fuel in the tank. A primary fuel filter (sock) is located
at the bottom of the electric fuel pump. Fuel is drawn
in through this filter, and up to the electric fuel
pump. High pressure fuel (unregulated) is supplied
from the electric fuel pump through a high-pressure
line to one of 3 fittings on the main fuel filter. If fuel
pressure at the pressure regulator exceeds approxi-
mately 49 psi, an internal diaphragm within the reg-
ulator closes, and excess fuel is routed through a
second fitting on the main fuel filter, and back into
the fuel tank (the fuel pressure regulator is installed
into the return side of the system). Pressure regu-
lated fuel is then delivered from the third fitting on
the fuel filter, up to and through the fuel rail, and on
to the fuel injectors.
A secondary fuel filter is attached to the side of the
fuel pump module. High-pressure from the electric
fuel pump causes a siphoning action across a passage
connected to this filter, and fuel is drawn into the
fuel pump module reservoir. This is used to help keep
the module reservoir full of fuel.
The fuel pressure regulator also acts as a check
valve to maintain some fuel pressure when the
engine is not operating. This will help to start the
engine. A second check valve is located at the outlet
of the fuel pump module housing.Refer to Fuel
Pump - Description and Operation for more
information. Also refer to the Fuel Pressure
Leak Down Test, and the Fuel Pump Pressure
Tests.
A separate fuel return line from the engine is not
used with this system.
REMOVAL
The fuel pressure regulator is located in the fuel
tank. It is attached to the bottom of the upper sec-
tion of the fuel pump module with a quick-connect
fitting (Fig. 19). The fuel pump module is supplied in
2 sections (upper and lower). To replace the pressure
regulator, the bottom section of the fuel pump mod-
ule must be replaced.
(1) Remove upper and lower sections of fuel pump
module from fuel tank. Refer to Fuel Pump Module
Removal/Installation.
(2) Replace lower section of fuel pump module
(includes fuel pressure regulator).
INSTALLATION
The fuel pressure regulator is located in the fuel
tank. It is attached to the bottom of the upper sec-
tion of the fuel pump module with a quick-connect
fitting. The fuel pump module is supplied in 2 sec-
tions (upper and lower). To replace the pressure reg-
ulator, the bottom section of the fuel pump module
must be replaced.
(1) Replace lower section of fuel pump module
(includes fuel pressure regulator).
(2) Install upper and lower sections of fuel pump
module to fuel tank. Refer to Fuel Pump Module
Installation.
Fig. 19 FUEL PRESSURE REGULATOR/SENDING
UNIT ELECTRICAL CONNECTOR
1 - UPPER SECTION OF PUMP MODULE
2 - QUICK-CONNECT FITTINGS
3 - FUEL PRESSURE REGULATOR
4 - 4-WIRE ELECTRICAL CONNECTOR
5 - FUEL TANK CHECK (CONTROL) VALVE
14 - 14 FUEL DELIVERYKJ
FUEL PRESSURE REGULATOR (Continued)
Page 1399 of 1803

WARNING: BEFORE PROCEEDING TO NEXT STEP,
NOTE THE FUEL PUMP WILL BE ACTIVATED AND
SYSTEM PRESSURE WILL BE PRESENT. THIS WILL
OCCUR AFTER CONNECTING TEST LEADS FROM
LCS ADAPTER INTO FUEL PUMP RELAY CAVITIES.
THE FUEL PUMP WILL OPERATE EVEN WITH IGNI-
TION KEY IN OFF POSITION. BEFORE ATTACHING
TEST LEADS, BE SURE ALL FUEL LINES AND
FUEL SYSTEM COMPONENTS ARE CONNECTED.
CAUTION: To prevent possible damage to the vehi-
cle electrical system and LCS adapter, the test
leads must be connected into relay cavities exactly
as shown in following steps.
Depending upon vehicle model, year or engine con-
figuration, three different types of relays may be
used: Type-1, type-2 and type±3.
(14) If equipped withtype±1 relay(Fig. 22),
attach test leads from LCS adapter into PDC relay
cavities number 30 and 87. For location of these cav-
ities, refer to numbers stamped to bottom of relay
(Fig. 22).
(15) If equipped withtype±2 relay(Fig. 23),
attach test leads from LCS adapter into PDC relay
cavities number 30 and 87. For location of these cav-
ities, refer to numbers stamped to bottom of relay
(Fig. 23).
(16) If equipped withtype±3 relay(Fig. 24),
attach test leads from LCS adapter into PDC relay
cavities number 3 and 5. For location of these cavi-
ties, refer to numbers stamped to bottom of relay
(Fig. 24).
Fig. 22 FUEL PUMP RELAY - TYPE 1
Fig. 23 FUEL PUMP RELAY - TYPE 2
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 24 FUEL PUMP RELAY - TYPE 3
TERMINAL LEGEND
NUMBER IDENTIFICATION
1 COIL BATTERY
2 COIL GROUND
3 COMMON FEED
4 NORMALLY CLOSED
5 NORMALLY OPEN
KJFUEL DELIVERY 14 - 17
FUEL PUMP (Continued)