2002 JEEP GRAND CHEROKEE oil

(7) Verify generator output wire (B+ wire) and
generator field connector are firmly connected to gen-
erator.
Fig. 4 Ignition Coil ConnectorÐ4.7L V-8 Engine
1 - IGNITION COIL
2 - COIL ELECTRICAL CONNECTOR
3 - COIL MOUNTING STUD/NUT
Fig. 5 Camshaft Position SensorÐ4.0L Engine
1 - OIL FILTER
2 - CAMSHAFT POSITION SENSOR
3 - CLAMP BOLT
4 - HOLD-DOWN CLAMP
5 - MOUNTING BOLTS (2)
6 - ELEC. CONNECTOR
Fig. 6 Camshaft Position SensorÐ4.7L V-8 Engine
1 - RIGHT CYLINDER HEAD
2 - CAMSHAFT POSITION SENSOR
3 - MOUNTING BOLT
4 - ELEC. CONNECTOR
Fig. 7 Crankshaft Position SensorÐ4.0L Engine
1 - SLOTTED HOLE
2 - CRANKSHAFT POSITION SENSOR
3 - WIRE SHIELD
4 - MOUNTING BOLT
5 - TRANSMISSION HOUSING
6 - PAPER SPACER
WJFUEL INJECTION 14 - 33
FUEL INJECTION (Continued)

(5) Push sensor against flywheel/drive plate. With
sensor pushed against flywheel/drive plate, tighten
mounting bolt to 7 N´m (60 in. lbs.) torque.
(6) Route sensor wiring harness into wire shield.
(7) Connect sensor pigtail harness electrical con-
nector to main wiring harness.
INSTALLATION - 4.7L
(1) Clean out machined hole in engine block.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into engine block with a slight
rocking action. Do not twist sensor into position as
damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to cylinder
block. If sensor is not flush, damage to sensor
mounting tang may result.
(4) Install mounting bolt and tighten to 28 N´m
(21 ft. lbs.) torque.
(5) Connect electrical connector to sensor.
(6) Install starter motor. Refer to Starter Removal/
Installation.
FUEL INJECTOR
DESCRIPTION
A separate fuel injector (Fig. 24) is used for each
individual cylinder.
OPERATION
OPERATION
The fuel injectors are electrical solenoids. The
injector contains a pintle that closes off an orifice at
the nozzle end. When electric current is supplied to
the injector, the armature and needle move a short
distance against a spring, allowing fuel to flow out
the orifice. Because the fuel is under high pressure, a
fine spray is developed in the shape of a pencil
stream. The spraying action atomizes the fuel, add-
ing it to the air entering the combustion chamber.
The top (fuel entry) end of the injector (Fig. 24) is
attached into an opening on the fuel rail.
The nozzle (outlet) ends of the injectors are posi-
tioned into openings in the intake manifold just
above the intake valve ports of the cylinder head.
The engine wiring harness connector for each fuel
injector is equipped with an attached numerical tag
(INJ 1, INJ 2 etc.). This is used to identify each fuel
injector.
The injectors are electrically energized, individu-
ally and in a sequential order by the Powertrain Con-
trol Module (PCM). The PCM will adjust injector
pulse width by switching the ground path to each
individual injector on and off. Injector pulse width is
the period of time that the injector is energized. The
PCM will adjust injector pulse width based on vari-
ous inputs it receives.
Battery voltage is supplied to the injectors through
the ASD relay.
The PCM determines injector pulse width based on
various inputs.
OPERATION - PCM OUTPUT
The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify each fuel injector with its
respective cylinder number.
The injectors are energized individually in a
sequential order by the Powertrain Control Module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs it
receives.
Battery voltage (12 volts +) is supplied to the injec-
tors through the ASD relay. The ASD relay will shut-
down the 12 volt power source to the fuel injectors if
the PCM senses the ignition is on, but the engine is
not running. This occurs after the engine has not
been running for approximately 1.8 seconds.
Fig. 24 Fuel InjectorÐ4.0L/4.7L Engines
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
WJFUEL INJECTION 14 - 43
CRANKSHAFT POSITION SENSOR (Continued)

The PCM determines injector on-time (pulse width)
based on various inputs.
DIAGNOSIS AND TESTING - FUEL INJECTOR
To perform a complete test of the fuel injectors and
their circuitry, use the DRB scan tool and refer to the
appropriate Powertrain Diagnostics Procedures man-
ual. To test the injector only, refer to the following:
Disconnect the fuel injector wire harness connector
from the injector. The injector is equipped with 2
electrical terminals (pins). Place an ohmmeter across
the terminals. Resistance reading should be approxi-
mately 12 ohms  1.2 ohms at 20ÉC (68ÉF).
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT PRESSURE EVEN WITH ENGINE OFF.
BEFORE SERVICING FUEL INJECTOR(S), FUEL
SYSTEM PRESSURE MUST BE RELEASED.
To remove one or more fuel injectors, the fuel rail
assembly must be removed from engine.
(1) Perform Fuel System Pressure Release Proce-
dure.
(2) Remove fuel injector rail. Refer to Fuel Injector
Rail Removal/Installation.
(3) Remove clip(s) retaining injector(s) to fuel rail
(Fig. 25).
(4) Remove injector(s) from fuel rail.
INSTALLATION
(1) Apply a small amount of engine oil to each fuel
injector o-ring. This will help in fuel rail installation.
(2) Install injector(s) and injector clip(s) to fuel
rail.
(3) Install fuel rail assembly. Refer to Fuel Injector
Rail Removal/Installation.
(4) Start engine and check for 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 turned
ON, 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.
IDLE AIR CONTROL MOTOR
DESCRIPTION
The IAC stepper motor is mounted to the throttle
body, and regulates the amount of air bypassing the
control of the throttle plate. As engine loads and
ambient temperatures change, engine rpm changes.
A pintle on the IAC stepper motor protrudes into a
passage in the throttle body, controlling air flow
through the passage. The IAC is controlled by the
Powertrain Control Module (PCM) to maintain the
target engine idle speed.
OPERATION
At idle, engine speed can be increased by retract-
ing the IAC motor pintle and allowing more air to
pass through the port, or it can be decreased by
restricting the passage with the pintle and diminish-
ing the amount of air bypassing the throttle plate.
The IAC is called a stepper motor because it is
moved (rotated) in steps, or increments. Opening the
IAC opens an air passage around the throttle blade
which increases RPM.Fig. 25 Fuel Injector MountingÐTypical (4.7L V-8
Engine Shown)
1 - INLET FITTING
2 - FUEL INJECTOR RAIL
3 - CLIP
4 - FUEL INJECTOR
14 - 44 FUEL INJECTIONWJ
FUEL INJECTOR (Continued)

GEAR
TABLE OF CONTENTS
page page
GEAR
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................16
INSTALLATION.........................16
ADJUSTMENTS
STEERING GEAR.....................18
SPECIFICATIONS
POWER STEERING GEAR..............18
SPECIAL TOOLS
POWER STEERING GEAR..............19
PITMAN SHAFT
REMOVAL.............................20INSTALLATION.........................20
PITMAN SHAFT BEARING
REMOVAL.............................22
INSTALLATION.........................22
PITMAN SHAFT SEAL
REMOVAL.............................22
INSTALLATION.........................23
RACK PISTON/VALVE ASSEMBLY
REMOVAL.............................23
INSTALLATION.........................25
STUB SHAFT HOUSING
REMOVAL.............................25
INSTALLATION.........................25
GEAR
DESCRIPTION
The power steering gear is a recirculating ball type
gear (Fig. 1) .
The following gear components can be serviced:
²Pitman Shaft and Cover
²Pitman Shaft Bearings
²Pitman Shaft Oil Seal/Dust Seal
²Stud Shaft Housing with Seal
²O-Rings and Teflon Rings
NOTE: If rack piston assembly is damaged the gear
must be replaced.
OPERATION
The gear acts as a rolling thread between the
worm shaft and rack piston. The worm shaft is sup-
ported by a thrust bearing at the lower end and a
bearing assembly at the upper end. When the worm
shaft is turned the rack piston moves. The rack pis-
ton teeth mesh with the pitman shaft. Turning the
worm shaft turns the pitman shaft, which turns the
steering linkage.
REMOVAL
(1) Place the front wheels in the straight ahead
position with the steering wheel centered and locked.
(2) Remove the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(3) Drain or siphon the power steering system.(4) Remove the pressure and return lines (Fig.
2)from the steering gear. Refer to hose removal in
this section.
(5) Remove the column coupler shaft bolt (Fig.
2)and remove the shaft from the gear.
(6) Raise and support the vehicle.
(7) Remove the left front wheel and tire assembly.
(8) Remove the pitman arm from gear with Puller
C-4150A.
(9) Remove the windshield washer reservoir,(Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - REMOVAL).
(10) Remove the steering gear mounting bolts.
Remove the steering gear out of the engine compart-
ment (Fig. 3).
INSTALLATION
(1) Position the steering gear on the frame rail and
install the bolts. Tighten the bolts to 108 N´m (80 ft.
lbs.) torque.
(2) Install the pitman arm and tighten nut to 251
N´m (185 ft. lbs.).
(3) Install windshield washer reservoir,(Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WASHER RES-
ERVOIR - INSTALLATION).
(4) Install the wheel and tire assembly.
(5) Remove the support and lower the vehicle.
(6) Install the pressure and return hoses to the
steering gear and tighten to 20-38 N´m (14-28 ft.
lbs.).
(7) Install the column coupler shaft.
(8) Install the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
19 - 16 GEARWJ

PITMAN SHAFT
REMOVAL
(1) Clean exposed end of pitman shaft and housing
with a wire brush.
(2) Rotate the stub shaft with a wrench (Fig.
5)from stop to stop and count the number of turns.
(3) Center the stub shaft by rotating it from the
stop 1/2 of the total amount of turns.
NOTE: The pitman shaft will not clear the housing if
it is not centered.
(4) Remove pitman shaft cover bolts and remove
the shaft assembly (Fig. 6).
(5) Remove pitman shaft cover o-ring.
(6) Remove pitman shaft dust seal from the hous-
ing with a Puller 7794-A and Slide Hammer C-637
(Fig. 7).
(7) Remove the pitman shaft oil seal retaining ring
with snap ring pliers (Fig. 8).
(8) Remove oil seal metal backup washer then
plastic backup washer from the housing.
(9) Remove pitman shaft oil seal from the housing
with a Puller 7794-A and Slide Hammer C-637 (Fig.
7).
(10) Drop Driver 8277 through the top bearing and
align the driver up with the lower bearing. (Fig. 9).
Install Handle C-4171 into the driver and remove the
lower bearing.
(11) Turn the gear over and remover the upper
bearing with Driver 8277 and Handle C-4171.
INSTALLATION
(1) Install upper pitman shaft bearing, with Driver
8294 and Handle C-4171 (Fig. 10). Drive bearing into
housing until the driver bottoms out.
NOTE: Install upper pitman shaft bearing with the
part number/letters facing the driver.
Fig. 5 Center Stub
1 - WRENCH
2 - STUB SHAFT
Fig. 6 Cover and Pitman Shaft
1 - ADJUSTER NUT
2 - PITMAN SHAFT COVER
3 - O-RING
4 - GEAR HOUSING
5 - PITMAN SHAFT
Fig. 7 Oil Seal Removal
1 - PULLER
2 - STEERING GEAR
19 - 20 GEARWJ

(2) Install lower pitman shaft bearing with the
other side Driver 8294 and Handle C-4171 (Fig. 11).
Drive bearing into housing until the bearing shoulder
is seated against the housing.
(3) Coat the oil seal and backup washers withspe-
cial greasesupplied with the new seal.
(4) Install the oil seal with Driver 8294 and Han-
dle C-4171.
(5) Install plastic backup washer.
NOTE: The plastic backup washer has a lip on the
inside diameter that faces down towards the oil
seal.
(6) Install metal backup washer.
(7) Install the retainer ring with snap ring pliers.(8) Coat the dust seal withspecial greasesup-
plied with the new seal.
(9) Install dust seal with Driver 8294 and Handle
C-4171.
(10) Install new pitman shaft cover o-ring.
(11) Install pitman shaft assembly into the hous-
ing.
(12) Install cover bolts and tighten to 62 N´m (46
ft. lbs.).
(13) Perform over-center rotation torque adjust-
ment.
Fig. 8 Oil Seal Retaining Ring
1 - SNAP RING PLIERS
2 - RETAINING RING
Fig. 9 Bearing Driver
1 - UPPER BEARING
2 - LOWER BEARING
3 - DRIVER
Fig. 10 Upper Pitman Shaft Bearing
1 - DRIVER
2 - UPPER BEARING
Fig. 11 Lower Pitman Shaft Bearing
1 - STEERING GEAR
2 - BEARING SHOULDER
3 - DRIVER
4 - LOWER BEARING
WJGEAR 19 - 21
PITMAN SHAFT (Continued)

PITMAN SHAFT BEARING
REMOVAL
(1) Clean exposed end of pitman shaft and housing
with a wire brush.
(2) Rotate the stub shaft with a wrench (Fig.
5)from stop to stop and count the number of turns.
(3) Center the stub shaft by rotating it from the
stop 1/2 of the total amount of turns.
NOTE: The pitman shaft will not clear the housing if
it is not centered.
(4) Remove pitman shaft cover bolts and remove
the shaft assembly (Fig. 6).
(5) Remove pitman shaft cover o-ring.
(6) Remove pitman shaft dust seal from the hous-
ing with a Puller 7794-A and Slide Hammer C-637
(Fig. 7).
(7) Remove the pitman shaft oil seal retaining ring
with snap ring pliers (Fig. 8).
(8) Remove oil seal metal backup washer then
plastic backup washer from the housing (Fig. 12).
(9)
Remove pitman shaft oil seal from the housing
with a Puller 7794-A and Slide Hammer C-637 (Fig. 7).
(10) Drop Driver 8277 through the top bearing and
align the driver up with the lower bearing. (Fig. 9).
Install Handle C-4171 into the driver and remove the
lower bearing.
(11) Turn the gear over and remover the upper
bearing with Driver 8277 and Handle C-4171.
INSTALLATION
(1) Install upper pitman shaft bearing, with Driver
8294 and Handle C-4171 (Fig. 10). Drive bearing into
housing until the driver bottoms out.NOTE: Install upper pitman shaft bearing with the
part number/letters facing the driver.
(2) Install lower pitman shaft bearing with the
other side Driver 8294 and Handle C-4171 (Fig. 11).
Drive bearing into housing until the bearing shoulder
is seated against the housing.
(3) Coat the oil seal and backup washers withspe-
cial greasesupplied with the new seal.
(4) Install the oil seal with Driver 8294 and Han-
dle C-4171.
(5) Install plastic backup washer.
NOTE: The plastic backup washer has a lip on the
inside diameter that faces down towards the oil
seal.
(6) Install metal backup washer.
(7) Install the retainer ring with snap ring pliers.
(8) Coat the dust seal withspecial greasesup-
plied with the new seal.
(9) Install dust seal with Driver 8294 and Handle
C-4171.
(10) Install new pitman shaft cover o-ring.
(11) Install pitman shaft assembly into the hous-
ing.
(12) Install cover bolts and tighten to 62 N´m (46
ft. lbs.).
(13) Perform over-center rotation torque adjust-
ment.
PITMAN SHAFT SEAL
REMOVAL
(1) Clean exposed end of pitman shaft and housing
with a wire brush.
(2) Rotate the stub shaft with a wrench (Fig.
5)from stop to stop and count the number of turns.
(3) Center the stub shaft by rotating it from the
stop 1/2 of the total amount of turns.
NOTE: The pitman shaft will not clear the housing if
it is not centered.
(4) Remove pitman shaft cover bolts and remove
the shaft assembly (Fig. 6).
(5) Remove pitman shaft cover o-ring.
(6) Remove pitman shaft dust seal from the hous-
ing with a Puller 7794-A and Slide Hammer C-637
(Fig. 7).
(7) Remove the pitman shaft oil seal retaining ring
with snap ring pliers (Fig. 8).
(8) Remove oil seal metal backup washer then
plastic backup washer from the housing (Fig. 12).
Fig. 12 Backup Washers
1 - METAL BACK UP WASHER
2 - PLASTIC BACK UP WASHER
19 - 22 GEARWJ

(9) Remove pitman shaft oil seal from the housing
with a Puller 7794-A and Slide Hammer C-637 (Fig.
7).
(10) Drop Driver 8277 through the top bearing and
align the driver up with the lower bearing. (Fig. 9).
Install Handle C-4171 into the driver and remove the
lower bearing.
(11) Turn the gear over and remover the upper
bearing with Driver 8277 and Handle C-4171.
INSTALLATION
(1) Install upper pitman shaft bearing, with Driver
8294 and Handle C-4171 (Fig. 10). Drive bearing into
housing until the driver bottoms out.
NOTE: Install upper pitman shaft bearing with the
part number/letters facing the driver.
(2) Install lower pitman shaft bearing with the
other side Driver 8294 and Handle C-4171 (Fig. 11).
Drive bearing into housing until the bearing shoulder
is seated against the housing.
(3) Coat the oil seal and backup washers withspe-
cial greasesupplied with the new seal.
(4) Install the oil seal with Driver 8294 and Han-
dle C-4171.
(5) Install plastic backup washer.
NOTE: The plastic backup washer has a lip on the
inside diameter that faces down towards the oil
seal.
(6) Install metal backup washer.
(7) Install the retainer ring with snap ring pliers.
(8) Coat the dust seal withspecial greasesup-
plied with the new seal.
(9) Install dust seal with Driver 8294 and Handle
C-4171.
(10) Install new pitman shaft cover o-ring.
(11) Install pitman shaft assembly into the hous-
ing.
(12) Install cover bolts and tighten to 62 N´m (46
ft. lbs.).
(13) Perform over-center rotation torque adjust-
ment.
RACK PISTON/VALVE
ASSEMBLY
REMOVAL
(1) Remove the steering gear (Refer to 19 -
STEERING/GEAR - REMOVAL).
(2) Clean exposed end of pitman shaft and housing
with a wire brush.
(3) Rotate the stub shaft with a wrench (Fig.
5)from stop to stop and count the number of turns.(4) Center the stub shaft by rotating it from the
stop 1/2 of the total amount of turns.
NOTE: The pitman shaft will not clear the housing if
it is not centered.
(5) Remove pitman shaft cover bolts and remove
the shaft assembly (Fig. 6).
(6) Remove the pitman shaft cover o-ring.
(7) Remove stub shaft housing bolts (Fig. 13).
(8) Remove the housing from the stub shaft (Fig.
14).
Fig. 13 Stub Shaft Housing
1 - STUB SHAFT HOUSING
2 - BOLTS
3 - STUB SHAFT
Fig. 14 Housing Removal
1 - STEERING GEAR
2 - STUB SHAFT HOUSING
WJGEAR 19 - 23
PITMAN SHAFT SEAL (Continued)