2002 JEEP GRAND CHEROKEE Control

tem functions, as well as separate hard wired sense
inputs to the BCM for the high speed continuous
wipe and front washer system functions.
The front wiper and washer system will only oper-
ate when the ignition switch is in the Accessory or
On positions. Battery current is directed from a B(+)
fuse in the Power Distribution Center (PDC) to the
wiper and washer system circuit breaker in the Junc-
tion Block (JB) through a fused ignition switch out-
put (run-acc) circuit. The automatic resetting circuit
breaker then provides battery current through a
fused ignition switch output (run-acc) circuit to the
wiper on/off relay, and the park switch in the front
wiper motor. A separate fuse in the JB provides bat-
tery current through another fused ignition switch
output (run-acc) circuit to the right multi-function
switch. The right multi-function switch circuitry uses
this battery feed to directly control the operation of
the front washer pump/motor unit. The BCM uses
low side drivers to control front wiper system opera-
tion by energizing or de-energizing the wiper high/
low and wiper on/off relays.
The hard wired circuits and components of the
front wiper and washer system may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), or the inputs to or out-
puts from the BCM that control the front wiper and
washer system operating modes. The most reliable,
efficient, and accurate means to diagnose the BCM,
or the BCM inputs and outputs related to the various
front wiper and washer system operating modes
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
Following are paragraphs that briefly describe the
operation of each of the front wiper and washer sys-
tem operating modes.
CONTINUOUS WIPE MODE
When the Low position of the control knob on the
control stalk of the right (wiper) multi-function
switch is selected, the Body Control Module (BCM)
energizes the wiper on/off relay. This directs battery
current through the normally open contacts of the
energized wiper on/off relay and the normally closed
contacts of the de-energized wiper high/low relay to
the low speed brush of the front wiper motor, causing
the front wipers to cycle at low speed. When the
High position of the control knob is selected, the
BCM energizes both the wiper on/off relay and the
wiper high/low relay. This directs battery current
through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speedbrush of the front wiper motor, causing the front wip-
ers to cycle at high speed.
When the Off position of the control knob is
selected, the BCM de-energizes both the wiper on/off
and wiper high/low relays, then one of two events
will occur. The event that will occur depends upon
the position of the wiper blades on the windshield at
the moment that the control knob Off position is
selected. If the wiper blades are in the down position
on the windshield when the Off position is selected,
the park switch that is integral to the front wiper
motor is closed to ground and the wiper motor ceases
to operate. If the wiper blades are not in the down
position on the windshield at the moment the Off
position is selected, the park switch is closed to bat-
tery current from the fused ignition switch output
(run-acc) circuit of the front wiper motor. The park
switch directs this battery current to the low speed
brush of the wiper motor through the wiper park
switch sense circuit and the normally closed contacts
of the wiper on/off and wiper high/low relays. This
causes the wiper motor to continue running at low
speed until the wiper blades are in the down position
on the windshield and the park switch is again
closed to ground.
INTERMITTENT WIPE MODE
On models not equipped with the optional auto-
matic wiper system, when the control knob on the
control stalk of the right (wiper) multi-function
switch is moved to one of the five Delay interval posi-
tions, the BCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The BCM monitors the chang-
ing state of the wiper motor park switch through a
hard wired front wiper park switch sense circuit
input. This input allows the BCM to determine the
proper intervals at which to energize and de-energize
the wiper on/off relay to operate the front wiper
motor intermittently for one low speed cycle at a
time. The BCM logic is also programmed to provide
an immediate wipe cycle and begin a new delay
interval timing cycle each time a shorter delay inter-
val is selected, and to add the remaining delay tim-
ing interval to the new delay interval timing before
the next wipe cycle occurs each time a longer delay
interval is selected.
The intermittent wipe mode delay times are speed
sensitive. The BCM monitors vehicle speed messages
received from the Powertrain Control Module (PCM)
over the Programmable Communications Interface
(PCI) data bus network in order to provide the speed
sensitive delay intervals. Above about sixteen kilome-
ters-per-hour (ten miles-per-hour) the delay is driver
adjustable from about one-half second to about eigh-
WJFRONT WIPERS/WASHERS 8R - 5
FRONT WIPERS/WASHERS (Continued)

teen seconds. Below about sixteen kilometers-per-
hour (ten miles-per-hour) the delay times are
doubled, from about one second to about thirty-six
seconds.
AUTOMATIC WIPE MODE
On models equipped with the optional automatic
wiper system, when the control knob on the control
stalk of the right (wiper) multi-function switch is
moved to one of the five Auto sensitivity positions,
the BCM sends an electronic message to the Rain
Sensor Module (RSM) over the Programmable Com-
munications Interface (PCI) data bus network indi-
cating the selected position. The RSM monitors an
area within the wipe pattern of the windshield glass
for the accumulation of moisture. Based upon inter-
nal programming and the selected sensitivity level,
when sufficient moisture has accumulated the RSM
sends the appropriate electronic wipe command mes-
sages to the BCM over the PCI data bus and the
BCM operates the front wiper system accordingly. As
the sensitivity level is set higher, the RSM is more
sensitive to moisture accumulation and will send
wipe commands more frequently. The BCM logic is
also programmed to provide an immediate wipe cycle
each time the control knob on the control stalk of the
right multi-function switch is moved from a non-au-
tomatic wipe position to one of the five Auto sensitiv-
ity positions, and another immediate wipe cycle each
time the control knob is moved from a lower Auto
sensitivity position to a higher Auto sensitivity posi-
tion.
MIST WIPE MODE
When the control stalk of the right (wiper) multi-
function switch is moved to the momentary Mist
position, the BCM energizes the wiper on/off relay for
as long as the Mist switch is held closed, then de-en-
ergizes the relay when the state of the Mist switch
input changes to open. The BCM can operate the
front wiper motor in this mode for only one low speed
cycle at a time, or for an indefinite number of
sequential low speed cycles, depending upon how
long the Mist switch is held closed.
WASH MODE
When the control stalk of the right (wiper) multi-
function switch is moved to the momentary front
Wash position while the control knob is in the Low or
High positions, the circuitry within the switch directs
battery current to the front washer pump/motor unit.
This will cause the front washer pump/motor unit to
be energized for as long as the front Wash switch is
held closed, and to de-energize when the front Wash
switch is released. When the control stalk of the
right (wiper) multi-function switch is moved to the
momentary front Wash position while the controlknob is in one of the Delay interval or Auto sensitiv-
ity positions, the front washer pump/motor operation
is the same. However, the BCM energizes the wiper
on/off relay to override the selected delay interval or
auto sensitivity level and operate the front wiper
motor in a continuous low speed mode for as long as
the front Wash switch is held closed, then de-ener-
gizes the relay and reverts to the selected delay mode
interval or auto sensitivity level several wipe cycles
after the front Wash switch is released. The BCM
detects the front Wash switch state through a hard
wired washer pump motor switch output circuit input
from the right multi-function switch.
WIPE-AFTER-WASH MODE
When the control stalk of the right (wiper) multi-
function switch is moved to the momentary front
Wash position while the control knob is in the Off
position, the BCM detects that switch state through
a hard wired washer pump motor switch output cir-
cuit input from the right multi-function switch. The
BCM responds to this input by energizing the wiper
on/off relay for as long as the Wash switch is held
closed, then de-energizes the relay several wipe
cycles after the front Wash switch is released. The
BCM monitors the changing state of the wiper motor
park switch through a hard wired front wiper park
switch sense circuit input. This input allows the
BCM to count the number of wipe cycles that occur
after the front Wash switch state changes to open,
and to determine the proper interval at which to de-
energize the wiper on/off relay to complete the wipe-
after-wash mode cycle.
DIAGNOSIS AND TESTING - FRONT WIPER &
WASHER SYSTEM
FRONT WIPER SYSTEM
If the front wiper motor operates, but the wipers
do not move on the windshield, replace the faulty
front wiper module. If the wipers operate, but chat-
ter, lift, or do not clear the glass, clean and inspect
the wiper system components as required. (Refer to 8
- ELECTRICAL/FRONT WIPERS/WASHERS -
INSPECTION) and (Refer to 8 - ELECTRICAL/
FRONT WIPERS/WASHERS - CLEANING). Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
The hard wired circuits and components of the
front wiper and washer system may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
8R - 6 FRONT WIPERS/WASHERSWJ
FRONT WIPERS/WASHERS (Continued)

ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), the Rain Sensor Mod-
ule (RSM), the Powertrain Control Module (PCM) or
the inputs to or outputs from these modules that con-
trol the various front wiper and washer system oper-
ating modes. The most reliable, efficient, and
accurate means to diagnose the BCM, the RSM, the
PCM or the BCM inputs and outputs related to the
various front wiper and washer system operating
modes requires the use of a DRBIIItscan tool. Refer
to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
FRONT WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative washer system. If the washer pump/mo-
tor operates, but no washer fluid is emitted from the
front washer nozzles, be certain to check the fluid
level in the reservoir. Also inspect the front washer
system components as required. (Refer to 8 - ELEC-
TRICAL/FRONT WIPERS/WASHERS - INSPEC-
TION). Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control knob on the control stalk of the
right (wiper) multi-function switch to the Low or
High wiper position. Check whether the front wiper
system is operating. If OK, go to Step 2. If not OK,
test and repair the front wiper system before con-
tinuing with these tests. Refer to FRONT WIPER
SYSTEM
(2) Turn the control knob on the control stalk of
the right (wiper) multi-function switch to the Off
position. Pull the control stalk of the right (wiper)
multi-function switch toward the steering wheel to
close the front washer switch. The front washer
pump should operate and the front wipers should
operate for about three sweep cycles after the switch
is released before they park. If the front wipers are
OK, but the front washers are not, go to Step 3. If
the front washers are OK, but the front wipers are
not, go to Step 5.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the left headlamp and dash wire harness
connector for the front washer pump/motor from the
pump/motor connector receptacle. Check for continu-
ity between the ground circuit cavity of the left head-
lamp and dash wire harness connector for the front
washer pump/motor and a good ground. There should
be continuity. If OK, go to Step 4. If not OK, repair
the open ground circuit to ground (G106) as required.
(4) Reconnect the battery negative cable. Turn the
ignition switch to the On position. While pulling the
control stalk of the right (wiper) multi-function
switch toward the steering wheel to close the front
washer switch, check for battery voltage at the
washer pump switch sense circuit cavity of the left
headlamp and dash wire harness connector for the
front washer pump/motor unit. If OK, replace the
faulty front washer pump/motor. If not OK, repair
the open washer pump switch sense circuit between
the right (wiper) multi-function switch and the front
washer pump/motor unit as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the instrument panel wire harness con-
nector (Connector C2) for the Body Control Module
(BCM) from the BCM connector receptacle. Recon-
nect the battery negative cable. Turn the ignition
switch to the On position. While pulling the control
stalk of the right (wiper) multi-function switch
toward the steering wheel to close the front washer
WJFRONT WIPERS/WASHERS 8R - 7
FRONT WIPERS/WASHERS (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)

connection. The mounting nut locks the wiper arm to
the threaded stud on the wiper pivot. The spring-
loaded wiper arm hinge controls the down-force
applied through the tip of the wiper arm to the wiper
blade on the glass. The hook formation on the tip of
the wiper arm provides a cradle for securing and
latching the wiper blade pivot block to the wiper
arm.
REMOVAL
(1) Lift the front wiper arm to its over-center posi-
tion to hold the wiper blade off of the glass and
relieve the spring tension on the wiper arm to wiper
pivot connection.
(2) Carefully pry the plastic nut cap off of the
pivot end of the wiper arm (Fig. 7).
(3) Remove the nut that secures the wiper arm to
the wiper pivot shaft.
(4) Use a suitable battery terminal puller to disen-
gage the wiper arm from the wiper pivot shaft
splines (Fig. 8).
(5) Remove the front wiper arm pivot end from the
wiper pivot.
INSTALLATION
NOTE: Be certain that the wiper motor is in the park
position before attempting to install the wiper arms.
Turn the ignition switch to the On position and
move the right multi-function switch control knob to
its Off position. If the wiper pivots move, wait until
they stop moving, then turn the ignition switchback to the Off position. The wiper motor is now in
its park position.
(1) The front wiper arms must be indexed to the
wiper pivots with the wiper motor in the park posi-
tion to be properly installed. Position the front wiper
arm pivot ends onto the wiper pivots so that the
lower edge of the blade is aligned with the wiper
alignment lines located in the lower edge of the
windshield glass (Fig. 7).
(2) Once the wiper blade is aligned, lift the wiper
arm away from the windshield slightly to relieve the
spring tension on the pivot end and push the pivot
hole on the end of the wiper arm down over the
wiper pivot shaft.
(3) Install and tighten the nut that secures the
wiper arm to the wiper pivot shaft. Tighten the nut
to 23.7 N´m (210 in. lbs.).
(4) Wet the windshield glass, then operate the
front wipers. Turn the wiper switch to the Off posi-
tion, then check for the correct wiper arm position
and readjust as required.
(5) Reinstall the plastic nut cap onto the wiper
arm pivot nut.
FRONT WIPER BLADE
DESCRIPTION
Each front wiper blade is secured by an integral
latching pivot block to the hook formation on the tip
of the front wiper arms, and rests on the glass near
the base of the windshield when the wipers are not
in operation (Fig. 9). The wiper blade consists of the
following components:
²Superstructure- The superstructure includes
several stamped steel bridges and links with claw
Fig. 7 Wiper Arm Remove/Install
1 - ARM AND BLADE
2 - CAP
3 - NUT
4 - PIVOT SHAFT
5 - ALIGNMENT LINE
Fig. 8 Wiper Arm Puller - Typical
1 - WIPER ARM
2 - WIPER PIVOT
3 - BATTERY TERMINAL PULLER
8R - 14 FRONT WIPERS/WASHERSWJ
FRONT WIPER ARM (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)

(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)

(1) Position the Rain Sensor Module (RSM) above
the inside rear view mirror (Fig. 15).
(2) Reconnect the overhead wire harness connector
for the RSM to the module connector receptacle.
(3) Position the RSM to the bracket on the wind-
shield above the inside rear view mirror.
(4) Using hand pressure, press the spring clips on
each side of the RSM until they snap over the
bracket on the windshield.
NOTE: The spring clips on the RSM will become
deformed after numerous (about ten) removal and
installation cycles. If the spring clips become
deformed, the RSM must be replaced with a new
unit.
(5) Align and engage the top of the trim cover over
the top of the RSM.
(6) Using hand pressure, press the bottom of the
trim cover toward the windshield glass until it snaps
over the bottom of the RSM.
(7) Reconnect the battery negative cable.
RIGHT MULTI-FUNCTION
SWITCH
DESCRIPTION
The right (wiper) multi-function switch is secured
to the right side of the multi-function switch mount-
ing housing at the top of the steering column, just
below the steering wheel (Fig. 16). The only visible
component of the right multi-function switch is the
control stalk that extends through a dedicated open-
ing in the right side of the steering column shrouds.
The remainder of the right multi-function switch is
concealed beneath the steering column shrouds. The
switch housing and its control stalk are constructed
of molded black plastic. A single connector receptacle
containing up to ten terminal pins is located on the
back of the switch housing and connects the switch
to the vehicle electrical system through a take out
and connector of the instrument panel wire harness.
The switch is secured to the multi-function switch
mounting housing near the top of the steering col-
umn by two screws.
There are two versions of the right multi-function
switch: one to support the standard equipment speed
sensitive intermittent front wiper system, and a sec-
ond to support the optional front automatic wiper
system. Each version of the right multi-function
switch control stalk has both white nomenclature
and International Control and Display Symbol icons
applied to it, which clearly identify its many func-
tions. The control stalk has a control knob on its end
with a flattened face to allow it to be easily rotated.
Just below the control knob is a knurled control
sleeve. The right multi-function switch is the primary
control for the front and rear wiper and washer sys-
tems, and contains switches and circuitry to provide
signals to the Body Control Module (BCM) and the
rear wiper module.
The right (wiper) multi-function switch cannot be
adjusted or repaired. If any function of the switch is
faulty, or if the switch is damaged, the entire switch
unit must be replaced.
The right (wiper) multi-function switch supports
the following functions and features:
²Automatic Front Wipe Mode- On models
equipped with the optional automatic wiper system,
the internal circuitry and hardware of the right
(wiper) multi-function switch control knob provide an
automatic front wipe mode with five sensitivity posi-
tions.
²Continuous Front Wipe Modes- The internal
circuitry and hardware of the right (wiper) multi-
function switch control knob provide two continuous
front wipe switch positions, low speed or high speed.
Fig. 16 Right (Wiper) Multi-Function Switch
1 - CONTROL STALK
2 - REAR WIPER CONTROL SLEEVE
3 - FRONT WIPER CONTROL KNOB
4 - RIGHT (WIPER) MULTI-FUNCTION SWITCH
8R - 20 FRONT WIPERS/WASHERSWJ
RAIN SENSOR MODULE (Continued)