2003 JEEP GRAND CHEROKEE 23 Body

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/
FRONT 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 together
using 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.
FRONT CHECK VALVE
DESCRIPTION
A front washer system check valve is standard
equipment on this model. The front check valve is
integral to the front washer nozzle plumbing wye fit-
ting located in the cowl plenum beneath the cowl ple-
num cover/grille panel near the base of the
windshield. The check valve consists of a molded
plastic body with a round center section. Three
barbed hose nipples are formed in a wye configura-
tion on the outside circumference of the center sec-
tion of the valve body. Within the check valve body, a
small check valve operated by a small coiled spring
restricts flow through the unit until the valve is
unseated by a predetermined inlet fluid pressure.
The front check valve cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The front check valve provides more than one func-
tion in this application. It serves as a wye connector
fitting between the cowl grille panel and washer noz-
zle sections of the front washer supply hose. It also
prevents washer fluid from draining out of the front
washer supply hoses back to the washer reservoir.
This drain-back would result in a lengthy delay from
when the front washer switch is actuated until
washer fluid was dispensed through the front washer
nozzles, because the front washer pump would have
to refill the front washer plumbing from the reservoir
to the nozzles. Finally, the front check valve prevents
washer fluid from siphoning through the front
washer nozzles after the front washer system is
turned Off. When the front washer pump pressurizes
and pumps washer fluid from the reservoir through
the front washer plumbing, the fluid pressure over-
rides the spring pressure applied to the check valve
and unseats the valve, allowing washer fluid to flow
toward the front washer nozzles. When the front
washer pump stops operating, spring pressure seats
the check valve and fluid flow in either direction
within the front washer plumbing is prevented.
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) Open the hood and pull the hood to plenum
seal off of the forward flanges of the cowl grille cover
and the plenum panel.
Fig. 2 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
WJFRONT WIPERS/WASHERS 8R - 9
FRONT WIPERS/WASHERS (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)

the more frequently the RSM will send wipe com-
mands to the BCM to operate the front wiper system.
The RSM operates on battery current received
through a fuse in the Junction Block (JB) on a fused
B(+) circuit. This circuit is switched by the power
accessory (sunroof) delay relay in the JB so that the
RSM will operate whenever the relay is energized by
the BCM. The RSM receives ground at all times
through a take out of the left body wire harness with
an eyelet terminal that is secured by a ground screw
to the front seat crossmember on the floor panel
under the left front seat. It is important to note that
the default condition for the wiper system is auto-
matic wipers Off; therefore, if no message is received
from the RSM by the BCM for more than about five
seconds, the automatic wipers will be disabled and
the BCM will default the front wiper system opera-
tion to the low speed continuous wipe mode.
The RSM ground and battery current inputs can be
diagnosed using conventional diagnostic tools and
methods. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the RSM
internal circuitry, the BCM, the PCI data bus net-
work, or the electronic messages received and trans-
mitted by the RSM over the PCI data bus. The most
reliable, efficient, and accurate means to diagnose
the RSM requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
REMOVAL
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) Disconnect and isolate the battery negative
cable.
(2) Adjust the inside rear view mirror on the wind-
shield downward far enough to access the lower edge
of the Rain Sensor Module (RSM) trim cover (Fig.
15).
(3) Using a small thin-bladed screwdriver inserted
into the notch at the bottom of trim cover, gently prythe trim cover away from the windshield glass until
it unsnaps from the RSM.
(4) Using a small thin-bladed screwdriver, gently
pry the spring clips on each side of the RSM away
from the bracket on the windshield.
(5) Pull the RSM away from the bracket on the
windshield far enough to access and disconnect the
overhead wire harness connector for the module from
the module connector receptacle.
(6) Remove the RSM from above the inside rear
view mirror.
INSTALLATION
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.
Fig. 15 Rain Sensor Module Remove/Install
1 - OVERHEAD CONSOLE
2 - REAR VIEW MIRROR CONNECTOR
3 - BRACKET
4 - REAR VIEW MIRROR BUTTON
5 - SPRING CLIP (2)
6 - RAIN SENSOR MODULE
7 - TRIM COVER
8 - WIRE HARNESS CONNECTOR
WJFRONT WIPERS/WASHERS 8R - 19
RAIN SENSOR 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)

²Continuous Rear Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control sleeve provides one continu-
ous rear wipe switch position.
²Front Washer Mode- The internal circuitry
and hardware of the right (wiper) multi-function
switch control stalk provide front washer system
operation.
²Front Wipe-After-Wash Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control stalk provide a wipe-after-
wash mode.
²Front Wiper Mist Mode- The internal cir-
cuitry and hardware of the right (wiper) multi-func-
tion switch control stalk provide a front wiper system
mist mode.
²Intermittent Front Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control knob provide an intermittent
front wipe mode with five delay interval positions,
except on models equipped with the optional auto-
matic wiper system.
²Intermittent Rear Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control ring provide one fixed inter-
val intermittent rear wipe mode switch position.
²Rear Washer Mode- The internal circuitry and
hardware of the right (wiper) multi-function switch
control stalk provide rear washer system operation.
OPERATION
The right (wiper) multi-function switch uses a com-
bination of resistor multiplexed and conventionally
switched outputs to control the many functions and
features it provides. The switch receives battery cur-
rent on a fused ignition switch output (run-acc) cir-
cuit from a fuse in the Junction Block (JB) whenever
the ignition switch is in the On or Accessory posi-
tions, and receives ground from the Body Control
Module (BCM) on a windshield wiper switch return
circuit. The right (wiper) multi-function switch may
be diagnosed using conventional diagnostic tools and
methods.
Following are descriptions of how the right (wiper)
multi-function switch control stalk operates to control
the functions and features it provides:
²Automatic Wipe Mode- On models equipped
with the optional automatic wiper system, the control
knob on the end of the right (wiper) multi-function
switch control stalk is rotated to one of five minor
intermediate detents to select the desired automatic
wipe sensitivity level. The control knob is rotated
rearward (counterclockwise) to reduce the sensitivity
(increase the interval between wipes), or forward
(clockwise) to increase the sensitivity (decrease the
interval between wipes). The right (wiper) multi-function switch provides a resistor multiplexed out-
put to the Body Control Module (BCM) on a
windshield wiper switch mux circuit. The BCM
responds by sending an electronic message to the
Rain Sensor Module (RSM) over the Programmable
Communications Interface (PCI) data bus indicating
the selected sensitivity level, and by operating the
front wiper system based upon electronic wipe com-
mands received from the RSM over the PCI data bus.
²Continuous Front Wipe Modes- The control
knob on the end of the right (wiper) multi-function
switch control stalk is rotated to an intermediate
detent that is one detent rearward (counterclockwise)
from the full forward (clockwise) detent to select the
low speed continuous front wiper mode, or to its full
forward (clockwise) detent to select the high speed
continuous front wiper mode. For the low speed
mode, the multi-function switch provides a resistor
multiplexed output to the Body Control Module
(BCM) on a windshield wiper switch mux circuit, and
the BCM responds by energizing the wiper on/off
relay in the Power Distribution Center (PDC) for the
front low speed continuous wipe mode. For the high
speed mode, the multi-function switch provides the
same resistor multiplexed output to the BCM on the
windshield wiper switch mux circuit as the low speed
mode, but also provides a ground output to the BCM
on a wiper high control circuit. The BCM responds to
these inputs by energizing the wiper on/off relay and
the wiper high/low relay in the PDC for the front
high speed continuous wipe mode.
²Continuous Rear Wipe Mode- The control
ring on the right (wiper) multi-function switch con-
trol stalk is rotated to the most forward (clockwise)
detent to select the continuous rear wiper mode. The
multi-function switch provides a battery current out-
put to the rear wiper motor on a rear wiper motor
control circuit to signal the rear wiper module to
operate the rear wiper motor in the continuous wipe
mode.
²Front Washer Mode- The control stalk of the
right (wiper) multi-function switch is pulled toward
the steering wheel to momentarily activate the front
washer pump/motor in the front washer mode. The
front washer pump will continue to operate in the
front washer mode until the control stalk is released.
The right (wiper) multi-function switch provides a
battery current output on a washer pump motor
switch output circuit to energize the front washer
pump in the front washer mode.
²Front Wiper Mist Mode- The control stalk of
the right (wiper) multi-function switch is pushed
towards the floor to momentarily activate the front
wiper motor in the mist mode. The front wiper motor
will continue to operate in the mist mode until the
control stalk is released. The right (wiper) multi-
WJFRONT WIPERS/WASHERS 8R - 21
RIGHT MULTI-FUNCTION SWITCH (Continued)

function switch provides a resistor multiplexed out-
put to the Body Control Module (BCM) on a
windshield wiper switch mux circuit, and the BCM
responds by energizing the wiper on/off relay in the
Power Distribution Center (PDC) to operate the front
wiper motor momentarily at low speed to provide the
front wiper mist mode.
²Intermittent Front Wipe Mode- On models
not equipped with the optional automatic wiper sys-
tem, the control knob on the end of the right (wiper)
multi-function switch control stalk is rotated to one
of five minor intermediate detents to select the
desired intermittent front wipe delay interval. The
control knob is rotated rearward (counterclockwise)
to increase the delay, or forward (clockwise) to
decrease the delay. The right (wiper) multi-function
switch provides a resistor multiplexed output to the
Body Control Module (BCM) on a windshield wiper
switch mux circuit. The BCM responds by monitoring
electronic vehicle speed messages received from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus,
then energizing the wiper on/off relay in the Power
Distribution Center (PDC) to operate the front wiper
motor at the proper delay intervals.
²Intermittent Rear Wipe Mode- The control
ring on the right (wiper) multi-function switch con-
trol stalk is rotated to the center detent to select the
intermittent rear wiper mode. The right (wiper)
multi-function switch provides a battery current out-
put to the rear wiper motor on a rear wiper motor
delay control circuit to signal the rear wiper module
to operate the rear wiper in the intermittent wipe
mode.
²Rear Washer Mode- The right (wiper) multi-
function switch control stalk is pushed forward
toward the instrument panel to a momentary posi-
tions to activate the rear washer pump/motor in the
rear washer mode. The rear washer pump will con-
tinue to operate in the rear washer mode until the
control stalk is released. The right (wiper) multi-
function switch provides battery current on a rear
washer pump motor control circuit to energize the
rear washer pump in the rear washer mode.DIAGNOSIS AND TESTING - RIGHT MULTI-
FUNCTION SWITCH
Be certain to perform the diagnosis for the front
wiper system, front washer system, rear wiper sys-
tem, and/or rear washer system before testing the
right multi-function switch. (Refer to 8 - ELECTRI-
CAL/FRONT WIPERS/WASHERS - DIAGNOSIS
AND TESTING) or (Refer to 8 - ELECTRICAL/REAR
WIPERS/WASHERS - DIAGNOSIS AND TESTING).
Refer to the appropriate wiring information. The wir-
ing 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 PASSIVE RESTRAINT SYS-
TEM 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 PASSIVE RESTRAINT
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right multi-function switch from
the steering column and disconnect the instrument
panel wire harness connector for the switch from the
switch connector receptacle.
(3) Using an ohmmeter, check the right multi-func-
tion switch continuity and resistances at the switch
terminals as shown in the Right Multi-Function
Switch test chart (Fig. 17).
8R - 22 FRONT WIPERS/WASHERSWJ
RIGHT MULTI-FUNCTION SWITCH (Continued)

switch mounting housing. Tighten the screws to 2.5
N´m (22 in. lbs.).
(3) Reconnect the instrument panel wire harness
connector for the right multi-function switch to the
switch connector receptacle.
(4) Position the lower tilting steering column
shroud to the underside of the steering column (Fig.
18).
(5) Install and tighten the screw that secures the
lower tilting steering column shroud to the multi-
function switch mounting housing. Tighten the screw
to 1.9 N´m (17 in. lbs.).
(6) Position the upper tilting column shroud over
the steering column with the hazard warning switch
button inserted through the hole in the upper surface
of the shroud. Align the upper tilting steering column
shroud to the lower shroud and snap the two shroud
halves together.
(7) Reconnect the battery negative cable.
WASHER FLUID LEVEL
SWITCH
DESCRIPTION
The washer fluid level switch is a single pole, sin-
gle throw reed-type switch mounted near the front of
the washer reservoir, forward of the two washer
pump/motors (Fig. 20). Only the molded plastic
switch mounting flange and connector receptacle are
visible when the switch is installed in the reservoir.A short nipple formation extends from the inner sur-
face of the switch mounting flange, and a barb on the
nipple near the switch mounting flange is press-fit
into a rubber grommet seal installed in the mounting
hole of the reservoir. A small plastic float pivots on
the end of a bracket that extends from the switch
nipple formation. Within the float is a small magnet,
which actuates the reed switch. The washer fluid
level switch cannot be adjusted or repaired. If faulty
or damaged, the switch must be replaced.
OPERATION
The washer fluid level switch uses a pivoting,
oblong float to monitor the level of the washer fluid
in the washer reservoir. The float contains a small
magnet. When the float pivots, the changing proxim-
ity of its magnetic field will cause the contacts of the
small, stationary reed switch to open or close. When
the fluid level in the washer reservoir is at or above
the float level, the float moves to a vertical position
and the switch contacts open. When the fluid level in
the washer reservoir falls below the pivoting float,
the float moves to a horizontal position and the
switch contacts close. The switch is connected to the
vehicle electrical system through a dedicated take
out and connector of the left headlamp and dash wire
harness. The switch receives a five volt reference sig-
nal from the Body Control Module (BCM) through
the washer fluid switch output circuit. The switch is
grounded at all times through another take out of
the left headlamp and dash wire harness with a sin-
gle eyelet terminal connector that is secured under a
ground screw near the top of the left front fender
inner shield in the engine compartment.
When the switch closes, the BCM senses the volt-
age change on the circuit. The BCM is programmed
to send low washer fluid messages to the Electronic
Vehicle Information Center (EVIC) over the Program-
mable Communications Interface (PCI) data bus. The
EVIC is programmed to respond to this message by
displaying the Washer Fluid Low warning and send-
ing a chime request message back to the BCM over
the PCI data bus. Then the BCM generates an audi-
ble chime tone warning. A resistor within the washer
fluid level switch allows the BCM to monitor and
diagnose this circuit. The BCM will store a Diagnos-
tic Trouble Code (DTC) for any fault that it detects.
For retrieval of this fault information and further
diagnosis of the washer fluid level switch, the BCM,
the EVIC, the PCI data bus, the BCM message out-
puts to the EVIC that control the Low Washer Fluid
indicator, or the EVIC message outputs to the BCM
that control chime service, a DRBIIItscan tool and
the appropriate diagnostic information are required.
Fig. 20 Washer Fluid Level Switch (Viewed from
Bottom of Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
WJFRONT WIPERS/WASHERS 8R - 25
RIGHT MULTI-FUNCTION SWITCH (Continued)

(6) Install and tighten the two screws that secure
the inboard mounting flange of the washer reservoir
to the left inner wheel house. Tighten the screws to
7.4 N´m (66 in. lbs.).
(7) Reconnect the left headlamp and dash wire
harness connectors for the two washer pump/motor
units to the pump/motor unit connector receptacles.
(8) Reinstall the liner into the left front fender
wheel house.
(9) Lower the vehicle.
(10) Install and tighten the one screw that secures
the washer reservoir filler neck to the left inner
fender shield (Fig. 23). Tighten the screw to 7.4 N´m
(66 in. lbs.).
(11) Reinstall the washer reservoir filler cap hinge
onto the hook on the filler neck and close the cap.
(12) Reconnect the two washer reservoir washer
hoses to the two engine compartment washer hoses
at the inline connectors located on the top of the left
front fender wheel house.
(13) Reinstall the air cleaner housing onto the top
of the left front fender wheel house. (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(14) Reconnect the battery negative cable.
WIPER HIGH/LOW RELAY
DESCRIPTION
The wiper high/low relay is located in the Power
Distribution Center (PDC) in the engine compart-
ment near the battery. The wiper high/low relay is a
conventional International Standards Organization
(ISO) micro relay (Fig. 25). Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The relay is contained within a small, rect-
angular, molded plastic housing and is connected to
all of the required inputs and outputs by five integral
male spade-type terminals that extend from the bot-
tom of the relay base.
The wiper high/low relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper high/low relay is an electromechanical
switch that uses a low current input from the Body
Control Module (BCM) to control a high current out-
put to the front wiper motor. The movable common
feed contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The wiper high/low relay terminals are connected
to the vehicle electrical system through a connector
receptacle in the Power Distribution Center (PDC).
The inputs and outputs of the wiper high/low relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the output of the wiper
on/off relay at all times through the wiper on/off
relay output circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Body
Control Module (BCM) through a front wiper high/
low relay control circuit. The BCM controls front
wiper motor operation by controlling a ground path
through this circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a circuit breaker in the Junction Block (JB) through
a fused ignition switch output (run-acc) circuit.
Fig. 25 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
WJFRONT WIPERS/WASHERS 8R - 29
WASHER RESERVOIR (Continued)