plenum JEEP GRAND CHEROKEE 2002 WJ / 2.G User Guide

(4) Remove the six plastic nuts (2 short and 4
long) that secure the cowl grille cover to the studs on
the cowl top panel near the base of the windshield
(Fig. 3).
(5) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(6) Disconnect the engine compartment washer
hose from the cowl grille cover washer hose at the
plastic elbow connector.
(7) Remove the cowl grille cover from the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield.
(8) From the underside of the cowl grille cover, dis-
connect the washer hoses from the three barbed nip-
ples of the wye fitting/check valve unit.
(9) Remove the wye fitting/check valve unit from
the underside of the cowl grille cover.
INSTALLATION
(1) Position the wye fitting/check valve unit to the
underside of the cowl grille cover.
(2) From the underside of the cowl grille cover,
reconnect the three washer hoses to the barbed nip-
ples of the wye fitting/check valve unit.
(3) Reinstall the washer hoses for the front washer
nozzles into their routing clips on the underside of
the cowl grille cover.
(4) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 3).(5) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(6) Reconnect the cowl grille cover washer hose to
the engine compartment washer hose at the elbow
connector.
(7) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install the long nuts to the right out-
board stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(8) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(9) Reinstall the wiper arms onto the wiper pivots.
(Refer to 8 - ELECTRICAL/FRONT WIPERS/WASH-
ERS/FRONT WIPER ARMS - INSTALLATION).
(10) Reconnect the battery negative cable.
FRONT WASHER HOSES/
TUBES
DESCRIPTION
The front washer plumbing consists of a small
diameter rubber hose that is routed from the barbed
outlet nipple of the front washer pump/motor on the
washer reservoir along the filler neck into the engine
compartment. In the engine compartment, a molded
plastic in-line fitting with barbed nipples joins the
washer hose to another section of hose that is routed
near the left headlamp and dash wire harness to the
cowl plenum area. The engine compartment washer
hose passes from the engine compartment into the
cowl plenum area through a dedicated hole with a
rubber grommet near the left end of the cowl plenum
panel. A molded plastic elbow fitting with barbed nip-
ples joins the engine compartment hose to the cowl
grille cover hose. The cowl grille cover washer hose is
routed through routing clips on the underside of the
cowl grille cover to a molded plastic wye fitting with
barbed nipples and an integral check valve. The cowl
grille cover hose is connected to one nipple on the
wye fitting and the two washer nozzle hoses are con-
nected to the other two wye fitting nipples. The
washer nozzle hoses are routed along the underside
of the cowl grille cover to the two washer nozzles.
Fig. 3 Cowl Grille Cover Remove/Install
1 - WASHER HOSE CONNECTION
2 - STUDS (6)
3 - COWL GRILLE COVER
4 - PLASTIC NUT (6)
8R - 10 FRONT WIPERS/WASHERSWJ
FRONT CHECK VALVE (Continued)

Washer hose is available for service only as roll
stock, which must then be cut to length. The molded
plastic washer hose fittings cannot be repaired. If
these fittings are faulty or damaged, they must be
replaced.
OPERATION
Washer fluid in the washer reservoir is pressurized
and fed by the front washer pump/motor through the
front washer system plumbing and fittings to the two
front washer nozzles. Whenever routing the washer
hose or a wire harness containing a washer hose, it
must be routed away from hot, sharp, or moving
parts; and, sharp bends that might pinch the hose
must be avoided.
FRONT WASHER NOZZLE
DESCRIPTION
The two front washer nozzles have integral snap
features that secure them in dedicated holes in the
cowl plenum cover/grille panel located near the base
of the windshield. The domed upper surface of the
washer nozzle is visible on the top of the plenum cov-
er/grille panel, and the nozzle orifice is oriented
towards the windshield glass. The washer plumbing
fittings for the washer nozzles are concealed beneath
the cowl plenum cover/grille panel. These fluidic
washer nozzles are constructed of molded plastic. The
cowl plenum cover/grille panel must be removed from
the vehicle to access the nozzles for service. The
washer nozzles cannot be adjusted or repaired. If
faulty or damaged, they must be replaced.
OPERATION
The two front washer nozzles are designed to dis-
pense washer fluid into the wiper pattern area on the
outside of the windshield glass. Pressurized washer
fluid is fed to each nozzle from the washer reservoir
by the front washer pump/motor through a single
hose, which is attached to a barbed nipple on each
front washer nozzle below the cowl plenum cover/
grille panel. The washer nozzles incorporate a fluidic
design, which causes the nozzle to emit the pressur-
ized washer fluid as an oscillating stream to more
effectively cover a larger area of the glass area to be
cleaned.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the wiper arms from the wiper pivots.
(Refer to 8 - ELECTRICAL/FRONT WIPERS/WASH-
ERS/FRONT WIPER ARMS - REMOVAL).
(3) Unlatch and open the hood.(4) Pull the hood to plenum seal off of the forward
flanges of the cowl grille cover and the plenum panel.
(5) Remove the six plastic nuts (2 short and 4
long) that secure the cowl grille cover to the studs on
the cowl top panel near the base of the windshield
(Fig. 4).
(6) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(7) Disconnect the engine compartment washer
hose from the cowl grille cover washer hose at the
plastic elbow connector.
(8) Remove the cowl grille cover from the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield.
(9) From the underside of the cowl grille cover, dis-
connect the washer hose(s) from the barbed nipple(s)
of the front washer nozzle(s).
(10) From the underside of the cowl grille cover,
release the integral snap features of the front washer
nozzle(s) and push the nozzle(s) out through the
mounting hole toward the top side of the cowl grille
cover.
INSTALLATION
(1) From the top side of the cowl grille cover,
insert the nipple end of the front washer nozzle(s)
through the mounting hole in the cowl grille cover.
(2) Push firmly and evenly on the top of the front
washer nozzle until the integral snap features lock
into place on the underside of the cowl grille cover.
(3) From the underside of the cowl grille cover,
reconnect the washer hose(s) to the barbed nipple(s)
of the front washer nozzle(s).
Fig. 4 Cowl Grille Cover Remove/Install
1 - WASHER HOSE CONNECTION
2 - STUDS (6)
3 - COWL GRILLE COVER
4 - PLASTIC NUT (6)
WJFRONT WIPERS/WASHERS 8R - 11
FRONT WASHER HOSES/TUBES (Continued)

(4) Reinstall the washer hoses for the front washer
nozzle(s) into their routing clips on the underside of
the cowl grille cover.
(5) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 4).
(6) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(7) Reconnect the cowl grille cover washer hose to
the engine compartment washer hose at the elbow
connector.
(8) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install the long nuts to the right out-
board stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(9) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(10) Close and latch the hood.
(11) Reinstall the wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS -
INSTALLATION).
(12) Reconnect the battery negative cable.
FRONT WASHER PUMP/
MOTOR
DESCRIPTION
The front washer pump/motor unit is located on
the outboard side and near the front of the washer
reservoir, between the left front inner and outer
fender panels (Fig. 5). A small permanently lubri-
cated and sealed electric motor is coupled to the
rotor-type washer pump. A seal flange with a large
barbed inlet nipple on the pump housing passes
through a rubber grommet seal installed in one of
two dedicated mounting holes near the bottom of the
washer reservoir. The front washer pump/motor unit
is always mounted in the lower pump mounting hole
of the reservoir. A smaller barbed outlet nipple on the
pump housing connects the unit to the front washer
hose. The washer pump/motor unit is retained on the
reservoir by the interference fit between the barbedpump inlet nipple and the grommet seal, which is a
light press fit. An integral electrical connector recep-
tacle is located on the top of the motor housing. The
front washer pump/motor unit cannot be repaired. If
faulty or damaged, the entire washer pump/motor
unit must be replaced.
OPERATION
The front washer pump/motor unit is connected to
the vehicle electrical system through a single take
out and two-cavity connector of the left headlamp
and dash wire harness. The washer pump/motor is
grounded at all times through a take out of the left
headlamp and dash wire harness with a single eyelet
terminal connector that is secured under a ground
screw to the top of the left inner fender shield in the
engine compartment. The front washer pump/motor
receives battery current on a fused ignition switch
output (run-acc) circuit through the closed contacts of
the momentary front washer switch within the right
multi-function switch only when the switch control
stalk is pulled towards the steering wheel. Washer
fluid is gravity-fed from the washer reservoir to the
inlet side of the washer pump. When the pump motor
is energized, the rotor-type pump pressurizes the
washer fluid and forces it through the pump outlet
nipple, the front washer plumbing, and the front
washer nozzles onto the windshield glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Fig. 5 Washer Pumps (Viewed from Bottom of
Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
8R - 12 FRONT WIPERS/WASHERSWJ
FRONT WASHER NOZZLE (Continued)

(2) Raise and support the vehicle.
(3) Remove the liner from the left front fender
wheel house.
(4) Disconnect the left headlamp and dash wire
harness connector for the front washer pump/motor
from the motor connector receptacle (Fig. 6).
(5) Disconnect the washer hose from the barbed
outlet nipple of the front washer pump/motor and
allow the washer fluid to drain into a clean container
for reuse.
(6) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the barbed inlet nipple of
the washer pump out of the rubber grommet seal in
the reservoir. Care must be taken not to damage the
reservoir.
(7) Remove the rubber grommet seal from the
washer pump mounting hole in the washer reservoir
and discard.
INSTALLATION
(1) Install a new rubber grommet seal into the
washer pump mounting hole in the washer reservoir.
Always use a new rubber grommet seal on the reser-
voir.
(2) Position the barbed inlet nipple of the washer
pump to the rubber grommet seal in the reservoir
(Fig. 6).
(3) Press firmly and evenly on the washer pump
until the barbed inlet nipple is fully seated in the
rubber grommet seal in the washer reservoir mount-
ing hole.(4) Reconnect the washer hose to the barbed outlet
nipple of the washer pump.
(5) Reconnect the left headlamp and dash wire
harness connector for the front washer pump/motor
unit to the motor connector receptacle.
(6) Reinstall the liner into the left front fender
wheel house.
(7) Lower the vehicle.
(8) Refill the washer reservoir with the washer
fluid drained from the reservoir during the removal
procedure.
(9) Reconnect the battery negative cable.
FRONT WIPER ARM
DESCRIPTION
The front wiper arms are the rigid members
located between the wiper pivots that protrude from
the cowl plenum cover/grille panel near the base of
the windshield and the wiper blades on the wind-
shield glass. These wiper arms feature an over-center
hinge that allows easy access to the windshield glass
for cleaning. The wiper arm has a die cast metal
pivot end with a large mounting hole with internal
serrations at one end. A molded black plastic cap fits
over the wiper arm retaining nut to conceal the nut
and this mounting hole following wiper arm installa-
tion. The wide end of a tapered, stamped steel chan-
nel hinges on and is secured with a hinge pin to the
blade end of the wiper arm pivot end. One end of a
long, rigid, stamped steel strap, with a small hole
near its pivot end, is riveted and crimped within the
narrow end of the stamped steel channel. The tip of
the wiper blade end of this strap is bent back under
itself to form a small hook. Concealed within the
stamped steel channel, one end of a long spring is
engaged with a wire hook on the underside of the die
cast pivot end, while the other end of the spring is
hooked through the small hole in the steel strap. The
entire wiper arm has a satin black finish applied to
all of its visible surfaces.
A wiper arm cannot be adjusted or repaired. If
damaged or faulty, the entire wiper arm unit must be
replaced.
OPERATION
The front wiper arms are designed to mechanically
transmit the motion from the wiper pivots to the
wiper blades. The wiper arm must be properly
indexed to the wiper pivot in order to maintain the
proper wiper blade travel on the glass. The mounting
hole formation with internal serrations in the wiper
arm pivot end interlocks with the serrations on the
outer circumference of the wiper pivot driver, allow-
ing positive engagement and finite adjustment of this
Fig. 6 Washer Pumps (Viewed from Bottom of
Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
WJFRONT WIPERS/WASHERS 8R - 13
FRONT WASHER PUMP/MOTOR (Continued)

(3) Insert the hook formation on the tip of the
wiper arm through the opening in the wiper blade
superstructure ahead of the wiper blade pivot block/
latch unit far enough to engage the pivot block with
the hook (Fig. 10).
(4) Slide the wiper blade pivot block/latch up into
the hook formation on the tip of the wiper arm until
the latch release tab snaps into its locked position.
Latch engagement will be accompanied by an audible
click.
(5) Gently lower the wiper blade onto the glass.
FRONT WIPER MODULE
DESCRIPTION
The front wiper module is secured with four screws
through rubber isolators to the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 11).
The ends of the wiper pivot shafts that protrude
through dedicated openings in the cowl plenum cov-
er/grille panel to drive the wiper arms and blades are
the only visible components of the front wiper mod-
ule. The front wiper module consists of the following
major components:
²Bracket- The front wiper module bracket con-
sists of a long tubular steel main member that has a
stamped pivot bracket formation near each end
where the two wiper pivots are secured. A stamped
steel mounting plate for the wiper motor is secured
with welds near the center of the main member.
²Crank Arm- The front wiper motor crank arm
is a stamped steel unit with a slotted hole on the
driven end that is secured to the wiper motor outputshaft with a nut, and a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the pivot lever
arms. The passenger side drive link has a plastic
socket-type bushing on each end. The driver side
drive link has a plastic socket-type bushing on one
end, and a plastic sleeve-type bushing on the other
end. The socket-type bushing on one end of each
drive link is snap-fit over the ball stud on the lever
arm of its respective pivot. The driver side drive link
sleeve-type bushing end is then fit over the motor
crank arm ball stud, and the other socket-type bush-
ing of the passenger side drive link is snap-fit over
the exposed end of the wiper motor crank arm ball
stud.
²Motor- The front wiper motor is secured with
three screws to the motor mounting plate near the
center of the wiper module bracket. The wiper motor
output shaft passes through a hole in the module
bracket, where a nut secures the wiper motor crank
arm to the motor output shaft. The two-speed perma-
nent magnet wiper motor features an integral trans-
mission, an internal park switch, and an internal
automatic resetting circuit breaker.
²Pivots- The two front wiper pivots are secured
to the ends of the wiper module bracket. The crank
arms that extend from the bottom of the pivot shafts
each have a ball stud on their end. The upper end of
each pivot shaft where the wiper arms will be fas-
tened each has an externally serrated drum with a
threaded stud secured to it.
The front wiper module cannot be adjusted or
repaired. If any component of the module is faulty or
damaged, the entire front wiper module unit must be
replaced. The reinforcement bracket and stud plate
are available for service replacement.OPERATION
The front wiper module operation is controlled by
the battery current inputs received by the wiper
motor from the wiper on/off and wiper high/low
relays. The wiper motor speed is controlled by cur-
rent flow to either the low speed or the high speed
set of brushes. The park switch is a single pole, sin-
gle throw, momentary switch within the wiper motor
that is mechanically actuated by the wiper motor
transmission components. The park switch alter-
nately closes the wiper park switch sense circuit to
ground or to battery current, depending upon the
position of the wipers on the glass. This feature
allows the motor to complete its current wipe cycle
after the wiper system has been turned Off, and to
park the wiper blades in the lowest portion of the
wipe pattern. The automatic resetting circuit breaker
protects the motor from overloads. The wiper motor
Fig. 11 Front Wiper Module
1 - FRONT WIPER MODULE
2 - SCREW (4)
3 - WIRE HARNESS CONNECTOR
4 - LOWER COWL PLENUM PANEL
8R - 16 FRONT WIPERS/WASHERSWJ
FRONT WIPER BLADE (Continued)

crank arm, the two wiper linkage members, and the
two wiper pivots mechanically convert the rotary out-
put of the wiper motor to the back and forth wiping
motion of the wiper arms and blades on the glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front wiper arms from the wiper
pivots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS - REMOVAL).
(3) Unlatch and open the hood.
(4) Remove the hood to plenum seal from the for-
ward flanges of the cowl grille cover and the plenum
panel.
(5) Remove the six plastic nuts (2 short and 4
long) that secure the cowl grille cover to the studs on
the cowl top panel near the base of the windshield
(Fig. 12).
(6) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(7) Disconnect the front washer engine compart-
ment hose from the cowl grille cover hose at the
elbow connector.
(8) Remove the cowl grille cover from the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield.
(9) Remove the four screws that secure the front
wiper module to the cowl plenum panel (Fig. 13).
(10) Lift the left end of the front wiper module far
enough to access the front wiper motor wire harness
connector.(11) Disconnect the left headlamp and dash wire
harness connector for the front wiper motor from the
front wiper motor pigtail wire connector.
(12) Remove the front wiper module from the cowl
plenum as a unit.
INSTALLATION
(1) Position the front wiper module into the cowl
plenum as a unit (Fig. 13).
(2) Lift the left end of the front wiper module far
enough to access the front wiper motor wire harness
connector.
(3) Reconnect the left headlamp and dash wire
harness connector for the front wiper motor to the
front wiper motor pigtail wire connector.
(4) Loosely install one of the front wiper module
mounting screws to the mounting hole near the pivot
on the right end of the module to locate the module
in the plenum.
(5) Working from left to right, install and tighten
the four screws that secure the front wiper module to
the cowl plenum panel. Tighten the screws to 8 N´m
(72 in. lbs.).
(6) Position the cowl grille cover onto the cowl ple-
num and cowl top panels through the opening
between the hood and the base of the windshield
(Fig. 12).
(7) Lift the left end of the cowl grille cover off of
the cowl plenum panel far enough to access the front
washer plumbing.
(8) Reconnect the front washer system engine com-
partment hose to the cowl grille cover hose at the
elbow connector.
Fig. 12 Cowl Grille Cover Remove/Install
1 - WASHER HOSE CONNECTION
2 - STUDS (6)
3 - COWL GRILLE COVER
4 - PLASTIC NUT (6)
Fig. 13 Front Wiper Module Remove/Install
1 - FRONT WIPER MODULE
2 - SCREW (4)
3 - WIRE HARNESS CONNECTOR
4 - LOWER COWL PLENUM PANEL
WJFRONT WIPERS/WASHERS 8R - 17
FRONT WIPER MODULE (Continued)

(9) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install long nuts to the right outboard
stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(10) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(11) Close and latch the hood.
(12) Reinstall the wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS -
INSTALLATION).
(13) Reconnect the battery negative cable.
RAIN SENSOR MODULE
DESCRIPTION
The Rain Sensor Module (RSM) is the primary
component of the automatic wiper system (Fig. 14).
The RSM is located on the inside of the windshield,
between the rear view mirror mounting button and
the windshield header and is concealed behind a
molded plastic trim cover that snaps over the modulehousing. The triangular-shaped molded black plastic
housing of the RSM has a rectangular opening
located on the upper end of the housing for the mod-
ule connector receptacle, which contains four termi-
nal pins. These terminal pins connect the rain sensor
to the vehicle electrical system through a dedicated
take out and connector of the overhead wire harness
that extends from above the headliner. Five openings
on the windshield side of the RSM housing are fitted
with eight convex clear plastic lenses. A metal spring
clip on each side of the housing near the bottom
secures the RSM to a plastic mounting bracket that
is bonded to the windshield glass. Concealed within
the RSM housing is the electronic circuitry of the
module, which includes four InfraRed (IR) diodes,
two photocells, and a microprocessor.
The RSM software is Flash compatible, which
means it can be reprogrammed using Flash repro-
gramming procedures. However, if any of the hard-
ware of the RSM is damaged or faulty, the entire
module must be replaced. The RSM bracket is ser-
viced as a unit with the windshield glass. If the
bracket is faulty, damaged, or separated from the
windshield glass, the windshield unit must be
replaced.
OPERATION
The microprocessor-based Rain Sensor Module
(RSM) senses moisture in the wipe pattern on the
outside of the windshield glass and sends wipe com-
mands to the Body Control Module (BCM). Four
InfraRed (IR) diodes within the RSM generate IR
light beams that are aimed by four of the convex
optical lenses near the base of the module through
the windshield glass. Four additional convex optical
lenses near the top of the RSM are focused on the IR
light beams on the outside of the windshield glass
and allow the two photocells within the module to
sense changes in the intensity of these IR light
beams. When sufficient moisture accumulates within
the wipe pattern of the windshield glass, the RSM
detects a change in the monitored IR light beam
intensity.
The internal programming of the RSM then sends
the appropriate electronic wipe command messages
to the BCM over the Programmable Communications
Interface (PCI) data bus. The BCM responds by acti-
vating or deactivating the front wiper system. The
BCM also sends electronic sensitivity level messages
to the RSM over the PCI data bus based upon the
driver-selected sensitivity setting of the control knob
on the control stalk of the right (wiper) multi-func-
tion switch. The higher the selected sensitivity set-
ting the more sensitive the RSM is to the
accumulated moisture on the windshield glass, and
Fig. 14 Rain Sensor Module
1 - SPRING CLIP (2)
2 - INFRARED LENS (4)
3 - HOUSING
4 - CONNECTOR RECEPTACLE
5 - PHOTOCELL LENS (4)
8R - 18 FRONT WIPERS/WASHERSWJ
FRONT WIPER MODULE (Continued)

CAL/REAR WIPERS/WASHERS - CLEANING). If
after cleaning the wiper blade and the glass, the
wiper blade fails to clear the glass without smearing,
streaking, chattering, hazing, or beading, replace the
wiper blade. Also, if a wiper blade is damaged or if
the squeegee rubber is damaged or deteriorated,
replace the wiper blade with a new unit. Do not
attempt to repair a wiper blade that is damaged.
WASHER SYSTEM
The washer system components should be
inspected periodically, not just when washer perfor-
mance problems are experienced. This inspection
should include the following points:
(1) Check for ice or other foreign material in the
washer reservoir. If contaminated, clean and flush
the washer system. (Refer to 8 - ELECTRICAL/
REAR WIPERS/WASHERS - CLEANING).
(2) Inspect the washer plumbing for pinched, leak-
ing, deteriorated, or incorrectly routed hoses and
damaged or disconnected hose fittings. Replace dam-
aged or deteriorated hoses and hose fittings. Leaking
washer hoses can sometimes be repaired by cutting
the hose at the leak and splicing it back togetherusing an in-line connector fitting. Similarly, sections
of deteriorated hose can be cut out and replaced by
splicing in new sections of hose using in-line connec-
tor fittings. Whenever routing a washer hose or a
wire harness containing a washer hose, it must be
routed away from hot, sharp, or moving parts. Also,
sharp bends that might pinch the washer hose must
be avoided.
REAR WASHER HOSES/TUBES
DESCRIPTION
The rear washer plumbing consists of small diam-
eter rubber hoses and molded plastic inline connector
fittings (Fig. 2). The washer reservoir hose is con-
nected to the barbed outlet nipple of the rear washer
pump/motor unit below the left front wheel house
extension and routed up the washer reservoir filler
neck to the engine compartment. Just rearward of
the washer reservoir filler neck in the engine com-
partment, an inline connector with barbed nipples
joins the reservoir hose to the engine compartment
hose. The engine compartment hose is routed along
the top of the left front fender wheel house to the
dash panel. The engine compartment hose passes
through a hole with a rubber grommet in the dash
panel into the passenger compartment. Below the
instrument panel in the passenger compartment near
the left cowl side inner panel, another inline connec-
tor joins the engine compartment hose to the A-pillar
hose. The A-pillar hose is routed up the left A-pillar
to the headliner. At the headliner, an inline connector
joins the A-pillar hose to the headliner hose. The
headliner hose is routed above the headliner and
Fig. 1 Wiper Blade Inspection
1 - WORN OR UNEVEN EDGES
2 - ROAD FILM OR FOREIGN MATERIAL DEPOSITS
3 - HARD, BRITTLE, OR CRACKED
4 - DEFORMED OR FATIGUED
5 - SPLIT
6 - DAMAGED SUPPORT COMPONENTS
Fig. 2 Rear Washer Plumbing
1 - UPPER COWL PLENUM PANEL
2 - WASHER HOSE FROM ENGINE COMPARTMENT
3 - A-PILLAR WASHER HOSE
4 - HEADLINER WASHER HOSE
8R - 38 REAR WIPERS/WASHERSWJ
REAR WIPERS/WASHERS (Continued)

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Trailer Tow Brake Lamp Relay BK Left Quarter Panel N/S
Trailer Tow Circuit Breaker BK Left Quarter Panel N/S
Trailer Tow Connector BK In Rear Bumper 39
Trailer Tow Left Turn Relay BK Left Quarter Panel N/S
Trailer Tow Right Turn Relay BK Left Quarter Panel N/S
Transfer Case Position Sensor BK On Transfer Case 7
Transmission Control Module
(4.7L)BK Rear of Engine Compartment 14, 15, 18
Transmission Control Module
C1 (Diesel)BK Right Rear Side of Engine
CompartmentN/S
Transmission Control Module
C2 (Diesel)BK Right Rear Side of Engine
Compartment8
Transmission Solenoid (4.0L
Gas)BK Left Side of Transmission 12
Transmission Solenoid
Assembly (Diesel)BK On Transmission 8
Transmission Solenoid/TRS
Assembly (4.7L)GY Left Side of Transmission 16
Underhood Lamp BK At Lamp 6
Vehicle Information Center BK In Overhead Console N/S
Viscous/Cabin Heater (Diesel) BK Left Rear of Engine Compartment N/S
Washer Fluid Level Switch GY Left Front of Engine Compartment 3, 4
Wastegate Solenoid (Diesel) Near Power Distribution Center N/S
Water In Fuel Sensor (Diesel) BK Left Rear of Engine Compartment N/S
GROUNDS
GROUND NUMBER LOCATION FIG.
G100 (4.0L and Diesel) Near Starter N/S
G100 (4.7L) Near Intake Plenum N/S
G101 Near Battery 2
G102 Right Side of Engine 14, 15
G103 Right Side of Engine 7, 8, 10, 11, 14, 15
G104 (4.0L) Right Rear of Engine 10, 11
G104 (4.7L) Left Side of Engine 13
G105 Right Side of Engine 8
G106 Left Side of Engine Compartment 3, 4
G107 Left Side of Engine Compartment 3, 4
G108 Near Power Distribution Center 5
G200 Near Airbag Control Module 19, 20, 21, 22
G201 Near Airbag Control Module 19, 20, 21, 22
G300 Near Right Front Seat 34, 36
G301 Near Left Front Seat 33, 35
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 11
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

INSTALLATION
INSTALLATION - 4.0L
The IAC motor is located on 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.
(4) Install air cleaner duct/air box to throttle body.
INSTALLATION - 4.7L
(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.
(4) Install air duct/air box to throttle body.
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)
The resistance values of the IAT sensor is the same
as for the Engine Coolant Temperature (ECT) sensor.
REMOVAL
REMOVAL - 4.0L
The Intake Manifold Air Temperature (IAT) sensor
is installed into the intake manifold plenum near the
front of the throttle body (Fig. 27).
(1) Disconnect electrical connector from sensor.
(2) Remove sensor from intake manifold.
REMOVAL - 4.7L
The Intake Manifold Air Temperature (IAT) sensor
is located on the left side of the intake manifold.
Threaded Type Sensor
(1) Disconnect electrical connector from sensor.
(2) Remove sensor from intake manifold (Fig. 28).
Snap-In Type Sensor
(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. 30)
or (Fig. 29) and rotate sensor about 1/4 turn counter-
clockwise for removal.
(4) Check condition of sensor o-ring.
Fig. 27 Intake Manifold Air Sensor LocationÐ4.0L
Engine
1 - MOUNTING BOLTS (4)
2 - THROTTLE BODY
3 - IAC MOTOR
4 - ELEC. CONN.
5 - TPS
6 - MAP SENSOR
7 - ELEC. CONN.
8 - IAT SENSOR
9 - ELEC. CONN.
14 - 46 FUEL INJECTIONWJ
IDLE AIR CONTROL MOTOR (Continued)