2002 JEEP GRAND CHEROKEE regulator

OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation:The pump outlet con-
tains a one-way check valve to prevent fuel flow back
into the tank and to maintain fuel supply line pres-
sure (engine warm) when pump is not operational. It
is also used to keep the fuel supply line full of gaso-
line when pump is not operational. After the vehicle
has cooled down, fuel pressure may drop to 0 psi
(cold fluid contracts), but liquid gasoline will remain
in fuel supply line between the check valve and fuel
injectors.Fuel pressure that has dropped to 0
psi on a cooled down vehicle (engine off) is a
normal condition.Refer to the Fuel Pressure Leak
Down Test for more information.
The electric fuel pump is not a separate, service-
able component.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FUEL PUMP
CAPACITY TEST
Before performing this test, verify fuel pump
pressure. Refer to Fuel Pump Pressure Test.
Use this test in conjunction with the Fuel Pres-
sure Leak Down Test.
(1) Release fuel system pressure. Refer to Fuel
Pressure Release Procedure.
(2) Disconnect fuel supply line at fuel rail. Refer to
Quick-Connect Fittings. Some engines may require
air cleaner housing removal before line disconnection.
(3) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16º fuel
lines and tool number 6631 is used for 3/8º fuel lines.
(4) Connect correct Fuel Line Pressure Test
Adapter Tool Hose into disconnected fuel supply line.
Insert other end of Adaptor Tool Hose into a gradu-
ated container.
(5) Remove fuel fill cap.
(6) To activate fuel pump and pressurize system,
obtain DRBtscan tool and actuate ASD Fuel System
Test.
(7) A good fuel pump will deliver at least 1/4 liter
of fuel in 7 seconds. Do not operate fuel pump for
longer than 7 seconds with fuel line disconnected as
fuel pump module reservoir may run empty.
(a) If capacity is lower than specification, but
fuel pump can be heard operating through fuel fill
cap opening, check for a kinked/damaged fuel sup-
ply line somewhere between fuel rail and fuel
pump module.(b) If line is not kinked/damaged, and fuel pres-
sure is OK, but capacity is low, replace fuel filter/
fuel pressure regulator. The filter/regulator may be
serviced separately on certain applications. Refer
to Fuel Filter/Fuel Pressure Regulator Removal/In-
stallation for additional information.
(c) If both fuel pressure and capacity are low,
replace fuel pump module assembly. Refer to Fuel
Pump Module Removal/Installation.
DIAGNOSIS AND TESTING - FUEL PUMP
AMPERAGE TEST
This amperage (current draw) test is to be done in
conjunction with the Fuel Pump Pressure Test, Fuel
Pump Capacity Test and Fuel Pressure Leak Down
Test. Before performing the amperage test, be sure
the temperature of the fuel tank is above 50É F (10É
C).
The DRBtScan Tool along with the DRB Low Cur-
rent Shunt (LCS) adapter (Fig. 8) and its test leads
will be used to check fuel pump amperage specifica-
tions.
(1) Be sure fuel tank contains fuel before starting
test. If tank is empty or near empty, amperage read-
ings will be incorrect.
(2) Obtain LCS adapter.
(3) Plug cable from LCS adapter into DRB scan
tool at SET 1 receptacle.
(4) Plug DRB into vehicle 16±way connector (data
link connector).
Fig. 8 LOW CURRENT SHUNT
1 - LOW CURRENT SHUNT ADAPTER
2 - PLUG TO DRB
3 - TEST LEAD RECEPTACLES
WJFUEL DELIVERY 14 - 9
FUEL PUMP (Continued)

(19) Disconnect test leads from relay cavities
immediately after testing.
FUEL PUMP PRESSURE TEST
Use this test in conjunction with other fuel system
tests. Refer to the Fuel Pump Capacity Test, Fuel
Pressure Leak Down Test and Fuel Pump Amperage
Test.
Check Valve Operation:The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not oper-
ational. It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors.Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition.When the elec-
tric fuel pump is activated, fuel pressure should
immediately(1±2 seconds) rise to specification.
The fuel system is equipped with a combination
fuel filter/fuel pressure regulator. The fuel pressure
regulator is not controlled by engine vacuum.
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT FUEL PRESSURE EVEN WITH THE ENGINE
OFF. BEFORE DISCONNECTING FUEL LINE AT
FUEL RAIL, THIS PRESSURE MUST BE RELEASED.REFER TO THE FUEL SYSTEM PRESSURE
RELEASE PROCEDURE.
(1) Remove pressure test port cap at fuel rail test
port (Fig. 12) or (Fig. 13) . Connect 0±414 kPa (0-60
psi) fuel pressure gauge (from gauge set 5069) to test
port pressure fitting on fuel rail (Fig. 14) .The DRB
III Scan Tool along with the PEP module, the
500 psi pressure transducer, and the transduc-
er-to-test port adapter may also be used in
place of the fuel pressure gauge.
(2) Start and warm engine and note pressure
gauge reading. The DRB scan tool may also be used
to power fuel pump. Fuel pressure should be 339 kPa
  34 kPa (49.2 psi   5 psi) at idle.
(3) If engine runs, but pressure is below 44.2 psi,
determine if fuel pump or filter/regulator is defective.
Proceed to next step:
(a) Check for a kinked fuel supply line some-
where between fuel rail and fuel pump module.
Fig. 11 FUEL PUMP RELAY - TYPE 3
TERMINAL LEGEND
NUMBER IDENTIFICATION
1 COIL BATTERY
2 COIL GROUND
3 COMMON FEED
4 NORMALLY CLOSED
5 NORMALLY OPEN
Fig. 12 Test Port Cap LocationÐ4.0L Engine
1 - INJ. #1
2 - INJ. #2
3 - INJ. #3
4 - INJ. #4
5 - INJ. #5
6 - INJ. #6
7 - FUEL INJECTOR RAIL
8 - FUEL DAMPER
9 - PRESSURE TEST PORT CAP
10 - MOUNTING BOLTS (4)
11 - QUICK-CONNECT FITTING
WJFUEL DELIVERY 14 - 11
FUEL PUMP (Continued)

(b) If line is not kinked and pressure is low,
raise vehicle and disconnect fuel pressure line at
fuel filter/fuel pressure regulator (Fig. 15) . Three
fuel lines are attached to filter/regulator. Thefuel
pressure lineis attached to the right side of fil-
ter/regulator. It is also the most rearward of the
two (Fig. 15) .
(c) Install Special 5/16º Fuel Line Adapter Tool #
6539 between disconnected fuel line and filter/reg-
ulator fitting
(d) Attach 0±60 psi fuel pressure test gauge to
ªTº fitting on tool 6539.
Fig. 13 Test Port Cap LocationÐ4.7L V-8 Engine
1 - MOUNTING BOLTS (4)
2 - INJ.#7
3 - INJ.#5
4 - QUICK-CONNECT FITTING
5 - INJ.#3
6 - FUEL INJECTOR RAIL
7 - INJ.#1
8 - CONNECTOR TUBE
9 - INJ.#2
10 - INJ.#4
11 - INJ.#6
12 - INJ.#8
13 - PRESSURE TEST PORT CAP
Fig. 14 Fuel Pressure Test Gauge (Typical Gauge
Installation at Test Port)
1 - SERVICE (TEST) PORT
2 - FUEL PRESSURE TEST GAUGE
3 - FUEL RAIL
Fig. 15 Fuel Filter/Fuel Pressure Regulator Location
1 - FUEL SUPPLY LINE (TO FUEL RAIL)
2 - EVAP LINE
3 - FUEL RETURN LINE (MALE)
4 - FUEL PRESSURE LINE (FEMALE)
5 - FUEL FILTER/PRESSURE REGULATOR
6 - FUEL TANK
14 - 12 FUEL DELIVERYWJ
FUEL PUMP (Continued)

(e) Use DRB scan tool to power fuel pump. If
pressure is now within specifications, replace fuel
filter/fuel pressure regulator.
(f) If pressure is still low, replace fuel pump
module.
(4) If operating pressure is above 54.2 psi, electric
fuel pump is OK, but fuel pressure regulator is defec-
tive. Replace fuel filter/fuel pressure regulator.
(5) Install test port cap to fuel rail test port.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module is installed in the top of the
fuel tank (Fig. 16). The fuel pump module (Fig. 17)
contains the following components:
²A separate fuel pick-up filter (strainer)
²An electric fuel pump
²A threaded locknut to retain module to tank
²A gasket between tank flange and module
²Fuel gauge sending unit (fuel level sensor)²Fuel supply tube (line) connection
²Fuel return tube (line) connection
The fuel gauge sending unit and pick-up filter may
be serviced separately. If the electrical fuel pump
requires service, the entire fuel pump module must
be replaced.
OPERATION
Refer to Fuel Pump, Fuel Filter/Fuel Pressure Reg-
ulator and Fuel Gauge Sending Unit.
REMOVAL
Fuel tank removal will be necessary for fuel pump
module removal.
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).
BEFORE SERVICING FUEL PUMP MODULE, FUEL
SYSTEM PRESSURE MUST BE RELEASED.
(1) Perform Fuel System Pressure Release Proce-
dure.
Fig. 16 FUEL TANK AND COMPONENTS
1 - FUEL PUMP MODULE 9 - TANK SUPPORT BRACKET (SMALL/FRONT)
2 - MODULE LOCK RING 10 - MODULE PIGTAIL HARNESS
3 - TANK SUPPORT BRACKETS (REAR) 11 - FUEL SUPPLY (PRESSURE) LINE
4 - CHECK VALVE 12 - FUEL RETURN LINE
5 - FUEL FILL HOSE 13 - SKID PLATE
6 - ORVR COMPONENTS 14 - TANK STRAPS (2)
7 - ORVR CONTROL VALVE 15 - FUEL TANK
8 - CONTROL VALVE LOCK RING
WJFUEL DELIVERY 14 - 13
FUEL PUMP (Continued)

(8) Connect fuel return and pressure lines to fuel
pump module fittings (Fig. 16). Refer to Quick-Con-
nect Fittings.
(9) Install fuel tank. Refer to Fuel Tank Installa-
tion.
FUEL RAIL
DESCRIPTION
DESCRIPTION - 4.7L
The fuel injector rail is used to mount the fuel
injectors to the engine. It is mounted to the intake
manifold (Fig. 20).
DESCRIPTION - 4.0L
The fuel injector rail is used to mount the fuel
injectors to the engine (Fig. 21). On the 4.0L 6±cylin-
der engine, afuel damperis located near the center
of the fuel rail (Fig. 21).
OPERATION
OPERATION - 4.7L
High pressure fuel from the fuel pump is routed to
the fuel rail. The fuel rail then supplies the neces-
sary fuel to each individual fuel injector.
A fuel pressure test port is located on the fuel rail
(Fig. 20). A quick-connect fitting with a safety latch
is used to attach the fuel line to the fuel rail.
The fuel rail is not repairable.
OPERATION - 4.0L
The fuel injector rail supplies the necessary fuel to
each individual fuel injector.
High pressure fuel from the fuel pump is routed to
the fuel rail. The fuel rail then supplies the neces-
sary fuel to each individual fuel injector.
The fuel damper is used only to help control fuel
pressure pulsations. These pulsations are the result
of the firing of the fuel injectors. It isnot usedas a
fuel pressure regulator. The fuel pressure regulator is
not mountedto the fuel rail on any engine. It is
located near the front of the fuel tank above the rear
axle. Refer to Fuel Filter/Fuel Pressure Regulator in
this group for information.
A fuel pressure test port is located on the fuel rail
(Fig. 21). A quick-connect fitting with a safety latch
is used to attach the fuel line to the fuel rail.
The fuel rail is not repairable.
REMOVAL
REMOVAL - 4.7L
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT PRESSURE EVEN WITH ENGINE OFF.
BEFORE SERVICING FUEL RAIL, FUEL SYSTEM
PRESSURE MUST BE RELEASED.
Fig. 20 Fuel Injector RailÐ4.7L V-8 Engine
1 - MOUNTING BOLTS (4)
2 - INJ.#7
3 - INJ.#5
4 - QUICK-CONNECT FITTING
5 - INJ.#3
6 - FUEL INJECTOR RAIL
7 - INJ.#1
8 - CONNECTOR TUBE
9 - INJ.#2
10 - INJ.#4
11 - INJ.#6
12 - INJ.#8
13 - PRESSURE TEST PORT CAP
WJFUEL DELIVERY 14 - 15
FUEL PUMP MODULE (Continued)

(19) Disconnect fuel return line at fuel filter/fuel
pressure regulator (Fig. 36). Refer to Quick-Connect
Fittings for procedures.
(20) Disconnect fuel pressure line at fuel filter/fuel
pressure regulator (Fig. 36). Refer to Quick-Connect
Fittings for procedures.
(21) Disconnect EVAP canister vent line near front
of tank (Fig. 36).
(22) Disconnect fuel pump module electrical con-
nector (pigtail harness) near front of tank (Fig. 36).
Harness connector is clipped to body.
(23) Remove left / front tank support bracket bolt
at frame (Fig. 37).
(24)WITHOUT TRAILER HITCH:Remove tank-
to-frame mounting bolts (Fig. 39). Remove rear tank
support bracket bolts at frame (Fig. 38). Carefully
lower tank until clear of vehicle. Place tank on floor.
(25)WITH TRAILER HITCH:Remove tank /
hitch mounting bolts (Fig. 40). Carefully lower tank
until clear of vehicle. Place tank on floor.
(26) If necessary, separate skid plate from fuel
tank by removing 2 fuel tank strap nuts (Fig. 39) and
remove 2 tank straps.
(27) If fuel pump module removal is necessary,
refer to Fuel Pump Module Removal/Installation.
(28) If hoses are to be removed at fuel tank end,
note painted alignment (indexing) markings on
hoses, and molded indexing tangs on tank before
removal. Remove hoses.
(29) If necessary, remove 3 fuel filler tube assem-
bly mounting bolts (Fig. 41) and remove fuel filler
tube.
INSTALLATION
CAUTION: HANDLE EVAP, LDP AND ORVR VAPOR /
VACUUM LINES VERY CAREFULLY. THESE LINES
AND HOSES MUST BE FIRMLY CONNECTED.
CHECK THE VAPOR/VACUUM LINES AT THE LDP,
LDP FILTER, EVAP CANISTER, EVAP CANISTER
PURGE SOLENOID AND ORVR COMPONENTS FOR
DAMAGE OR LEAKS. IF A LEAK IS PRESENT, A
DIAGNOSTIC TROUBLE CODE (DTC) MAY BE SET.
(1) If necessary, position fuel filler tube assembly
to body. Install 3 bolts and tighten to 2 N´m (15 in.
lbs.) torque.
(2) If necessary, connect quick-connect fittings to
fuel pump module.
(3) If fuel pump module is being installed, refer to
Fuel Pump Module Removal/Installation.
(4) Install fuel fill/vent hoses to tank fittings. To
prevent hoses from kinking, rotate each hose until
painted indexing mark on hose is aligned to molded
indexing tang on tank.
(5) Install hose clamps to hoses. Refer to Torque
Specifications.(6) If necessary, position fuel tank into skid plate.
Install 2 tank straps and 2 strap nuts (Fig. 39). Refer
to Torque Specifications.
(7) Position fuel tank / skid plate assembly to
hydraulic jack.
(8) Raise tank into position to frame.
(9)WITH TRAILER HITCH:Position trailer
hitch and tow hooks (Fig. 40) to bottom of fuel tank.
Install bolts and nuts loosely.
(10)WITHOUT TRAILER HITCH:Install 2 rear
tank support brackets and bolts (Fig. 38). Install
tank-to-frame bolts. Do not tighten bolts / nuts at
this time.
(11) Install 1 left / front tank support bracket and
bolts / nuts (Fig. 37). Do not tighten bolts / nuts at
this time.
(12) Be sure fuel tank is properly aligned to frame
and body. Tighten all tank, tow hook and trailer
hitch bolts / nuts except for 3 support brackets.
Tighten all 3 (2 rear and 1 left / front) support
bracket bolts / nuts last. Refer to Torque Specifica-
tions.
(13)
(14) Connect fuel pump module pigtail harness
electrical connector near front of tank.
(15) Connect both fuel lines to fuel filter/fuel pres-
sure regulator. Refer to Quick-Connect Fittings for
procedures.
(16) Connect EVAP hose near front of tank.
(17) Position rear axle vent hose and install new
tie strap (Fig. 32).
(18) Install heat shield nuts / bolts (Fig. 35). Refer
to Torque Specifications.
(19) Connect ORVR hose elbow (Fig. 33) to top of
EVAP canister.
(20) Connect fuel vent hose to fuel vent tube (Fig.
32).
(21) Install fuel fill hose and clamp to fuel fill tube
(Fig. 32).
(22) Install 3 LDP mounting bolts (Fig. 29).
(23) While raising support bracket, connect LDP
wiring clip (Fig. 31). Install front section of two-piece
support bracket to rear section with 3 attaching bolts
located on bottom of support bracket (Fig. 30).
(24) Install support bracket brace bolt (Fig. 30).
(25) Tighten 2 support bracket nuts at frame rail
(Fig. 29).
(26) Install fuel tank-to-rear bumper fascia clips
(Fig. 34).
(27) Using new plastic rivets, install stone shield
behind left/rear wheel (Fig. 28).
(28) Install left rear wheel/tire.
(29) Lower vehicle and connect negative battery
cable to battery.
(30) Fill tank with fuel and check for leaks.
14 - 20 FUEL DELIVERYWJ
FUEL TANK (Continued)

Fig. 35 FUEL TANK HEAT SHIELD BOLTS
1 - FUEL TANK
2 - HEAT SHIELD BOLTS
Fig. 36 FUEL FILTER/FUEL PRESSURE REGULATOR
1 - FUEL RETURN LINE
2 - FUEL SUPPLY LINE (TO FUEL RAIL)
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - FUEL PRESSURE LINE
5 - REAR AXLE
6 - ELEC. CONNECTOR
7 - EVAP LINE
14 - 24 FUEL DELIVERYWJ
FUEL TANK (Continued)

(23) Inspect for pinched or leaking fuel tubes/lines.
Inspect for pinched, cracked or leaking fuel hoses.
(24) Inspect for exhaust system restrictions such
as pinched exhaust pipes, collapsed muffler or
plugged catalytic convertor.
(25) If equipped with automatic transmission, ver-
ify electrical harness is firmly connected to park/neu-
tral switch and to transmission components.
(26) Verify fuel pump module pigtail harness elec-
trical connector (Fig. 15) is firmly connected to body
harness connector.
(27) Inspect fuel line harness (from fuel pump
module) at fuel filter/fuel pressure regulator (Fig. 15)
for chaffing, cracks or leaks.
(28) Verify battery cable and solenoid feed wire
connections to starter solenoid are tight and clean.
(29) Inspect for chaffed wires or wires rubbing up
against other components.
(30) Inspect for chaffed vacuum lines or lines rub-
bing up against other components.
Fig. 15 Fuel Filter/Fuel Pressure Regulator Location
1 - FUEL RETURN LINE
2 - FUEL SUPPLY LINE (TO FUEL RAIL)
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - FUEL PRESSURE LINE
5 - REAR AXLE
6 - ELEC. CONNECTOR
7 - EVAP LINE
14 - 38 FUEL INJECTIONWJ
FUEL INJECTION (Continued)