2002 JEEP GRAND CHEROKEE rain sensor

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. Remove the instrument cluster from the
instrument panel and disconnect the instrument
panel wire harness for the instrument cluster from
the cluster connector receptacle.
(2) Reconnect the battery negative cable. Activate
the hazard warning system by moving the hazard
warning switch button to the On position. Check for
battery voltage at the inoperative (right or left) turn
signal circuit cavity of the instrument panel wire
harness connector for the instrument cluster. There
should be a switching (on and off) battery voltage sig-
nal present. If OK, replace the faulty (right or left)
turn signal indicator bulb. If not OK, repair the open
(right or left) turn signal circuit between the instru-
ment cluster and the combination flasher in the
Junction Block (JB) as required.
VOLTAGE GAUGE
DESCRIPTION
A voltage gauge is standard equipment on all
instrument clusters. The voltage gauge is located in
the upper left corner of the instrument cluster, to the
left of the tachometer. The voltage gauge consists of a
movable gauge needle or pointer controlled by the
instrument cluster circuitry and a fixed 90 degree
scale on the gauge dial face that reads left-to-right
from 9 volts to 19 volts. An International Control and
Display Symbol icon for ªBattery Charging Condi-
tionº is located on the gauge dial face.
The voltage gauge graphics are either white, gray
and orange against a black gauge dial face (base
cluster) or black, gray and red against a taupe gauge
dial face (premium cluster), making them clearly vis-
ible within the instrument cluster in daylight. When
illuminated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-rior lamps turned On, the base cluster white gauge
graphics appear blue-green and the orange graphics
still appear orange, while the premium cluster taupe
gauge dial face appears blue-green with the black
graphics silhouetted against the illuminated back-
ground and the red graphics still appear red. The
gray gauge graphics for both versions of the cluster
are not illuminated. The orange gauge needle in the
base cluster gauge is internally illuminated, while
the black gauge needle in the premium cluster gauge
is not.
Base cluster gauge illumination is provided by
replaceable incandescent bulb and bulb holder units
located on the instrument cluster electronic circuit
board. Premium cluster gauge illumination is pro-
vided by an integral electro-luminescent lamp that is
serviced as a unit with the instrument cluster. The
voltage gauge is serviced as a unit with the instru-
ment cluster.
OPERATION
The voltage gauge gives an indication to the vehi-
cle operator of the electrical system voltage. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
voltage gauge is an air core magnetic unit that
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (run-start) circuit whenever the igni-
tion switch is in the On or Start positions. The clus-
ter is programmed to move the gauge needle back to
the low end of the scale after the ignition switch is
turned to the Off position. The instrument cluster
circuitry controls the gauge needle position and pro-
vides the following features:
²System Voltage Message- Each time the clus-
ter receives a message from the PCM indicating the
system voltage, the cluster moves the gauge needle to
the relative voltage level position on the gauge scale.
²System Voltage Low Message- Each time the
cluster receives a message from the PCM indicating
the system voltage is low (system voltage is about
eleven volts or lower), the gauge needle is moved to
the relative voltage position in the red zone of the
gauge scale and the check gauges indicator is illumi-
nated. The gauge needle remains in the red zone and
the check gauges indicator remains illuminated until
the cluster receives a message from the PCM indicat-
ing there is no low system voltage condition (system
voltage is above about eleven volts, but lower than
about sixteen volts).
²System Voltage High Message- Each time
the cluster receives a message from the PCM indicat-
8J - 34 INSTRUMENT CLUSTERWJ
TURN SIGNAL INDICATOR (Continued)

inputs to the instrument cluster that control the
wait-to-start indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
WATER-IN-FUEL INDICATOR
DESCRIPTION
A water-in-fuel indicator is only found in the
instrument clusters of vehicles equipped with an
optional diesel engine. The water-in-fuel indicator is
located near the left edge of the instrument cluster,
to the left of the tachometer. The water-in-fuel indi-
cator consists of an International Control and Dis-
play Symbol icon for ªWater in Fuelº imprinted on a
red lens. The lens is located behind a cutout in the
opaque layer of the instrument cluster overlay. The
dark outer layer of the overlay prevents the icon
from being clearly visible when the indicator is not
illuminated. The icon appears silhouetted against a
red field through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED), which is
soldered onto the instrument cluster electronic circuit
board. The water-in-fuel indicator lens is serviced as
a unit with the instrument cluster lens, hood and
mask unit.
OPERATION
The water-in-fuel indicator gives an indication to
the vehicle operator when there is excessive water in
the fuel system. This indicator is controlled by a
transistor on the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The water-in-
fuel indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator tooperate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the indicator will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the water-in-fuel indicator for the following
reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the water-in-fuel indicator
is illuminated for about three seconds as a bulb test.
²Water-In-Fuel Indicator Lamp-On Message-
Each time the cluster receives a water-in-fuel indica-
tor lamp-on message from the PCM indicating there
is excessive water in the diesel fuel system, the
water-in-fuel indicator will be illuminated. The indi-
cator remains illuminated until the cluster receives a
water-in-fuel indicator lamp-off message, or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the water-in-fuel indicator
will be turned on for the duration of the test to con-
firm the functionality of the LED and the cluster con-
trol circuitry.
The PCM continually monitors the water-in-fuel
sensor to determine whether there is excessive water
in the diesel fuel. The PCM then sends the proper
water-in-fuel indicator lamp-on and lamp-off mes-
sages to the instrument cluster. For further diagnosis
of the water-in-fuel indicator or the instrument clus-
ter circuitry that controls the indicator, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
water-in-fuel sensor, the PCM, the PCI data bus, or
the electronic message inputs to the instrument clus-
ter that control the water-in-fuel indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
8J - 36 INSTRUMENT CLUSTERWJ
WAIT-TO-START INDICATOR (Continued)

²RETRAIN TIRE SENSORS?- This program-
mable feature only applies to vehicles equipped with
the optional tire pressure monitoring system. The
options include Yes and No. The default is No. When
Yes is selected and the menu button is depressed, the
EVIC will enter the training mode starting with the
left front tire.
²EASY EXIT SEAT?- This programmable fea-
ture only applies to vehicles equipped with the
optional memory system. The options include Yes and
No. The default is No. When Yes is selected, the
driver seat moves rearward about 55 millimeters
(two inches) or to the farthest rearward position,
whichever comes first, when the key is removed from
the ignition switch lock cylinder. This provides addi-
tional ease for exiting from the vehicle. The seat will
automatically return to the memory system setting
position when the Driver 1 or Driver 2 button of the
memory switch on the door panel is depressed or, if
theREMOTE LINKED TO MEMORYprogramma-
ble feature is enabled, when the RKE Unlock button
is depressed. While not automatic, an easy entry fea-
ture can be obtained by enabling theEASY EXIT
SEATfeature and disabling theREMOTE LINKED
TO MEMORYfeature. Then theEASY EXIT SEAT
feature will move the seat back, but the RKE unlock
event will not reposition the seat. Thus, the seat
remains positioned for easy entry, and the memory
switch on the door panel can be depressed after
entering the vehicle to return the seat to the desired
memory position.
STANDARD PROCEDURE - COMPASS
DEMAGNETIZING
A degaussing tool (Special Tool 6029) is used to
demagnetize, or degauss, the overhead console for-
ward mounting screw and the roof panel above the
overhead console. Equivalent units must be rated as
continuous duty for 110/115 volts and 60 Hz. They
must also have a field strength of over 350 gauss at 7
millimeters (0.25 inch) beyond the tip of the probe.
To demagnetize the roof panel and the overhead
console forward mounting screw, proceed as follows:
(1) Be certain that the ignition switch is in the Off
position, before you begin the demagnetizing proce-
dure.
(2) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(3) Slowly approach the head of the overhead con-
sole forward mounting screw with the degaussing
tool connected.
(4) Contact the head of the screw with the plastic
coated tip of the degaussing tool for about two sec-
onds.(5) With the degaussing tool still energized, slowly
back it away from the screw. When the tip of the tool
is at least 61 centimeters (2 feet) from the screw
head, disconnect the tool.
(6) Place a piece of paper approximately 22 by 28
centimeters (8.5 by 11 inches), oriented on the vehicle
lengthwise from front to rear, on the center line of
the roof at the windshield header (Fig. 3). The pur-
pose of the paper is to protect the roof panel from
scratches, and to define the area to be demagnetized.
(7) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(8) Slowly approach the center line of the roof
panel at the windshield header, with the degaussing
tool connected.
(9) Contact the roof panel with the plastic coated
tip of the degaussing tool. Be sure that the template
is in place to avoid scratching the roof panel. Using a
slow, back-and-forth sweeping motion, and allowing
13 millimeters (0.50 inch) between passes, move the
tool at least 11 centimeters (4 inches) to each side of
the roof center line, and 28 centimeters (11 inches)
back from the windshield header.
(10) With the degaussing tool still energized,
slowly back it away from the roof panel. When the
Fig. 3 Roof Demagnetizing Pattern
8M - 4 MESSAGE SYSTEMSWJ
OVERHEAD CONSOLE (Continued)

for door and liftgate open indications and to show if a
turn signal has been left on. The EVIC messages and
displays are coordinated with warning indicators in
the instrument cluster to avoid duplication.
The EVIC module contains a central processing
unit and interfaces with other electronic modules in
the vehicle over the Programmable Communications
Interface (PCI) data bus network. The PCI data bus
network allows the sharing of sensor information.
This helps to reduce wire harness complexity, reduce
internal controller hardware, and reduce component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities.
The EVIC module includes the following display
options:
²Compass and Temperature- provides the out-
side temperature and one of eight compass readings
to indicate the direction the vehicle is facing.
²Average fuel economy- shows the average
fuel economy since the last trip computer reset.
²Distance to empty- shows the estimated dis-
tance that can be travelled with the fuel remaining
in the fuel tank. This estimated distance is computed
using the average miles-per-gallon from the last 30
gallons of fuel used.
²Instant fuel economy- shows the present fuel
economy based upon the current vehicle distance and
fuel used information.
²Trip distance- shows the distance travelled
since the last trip computer reset.
²Elapsed time- shows the accumulated igni-
tion-on time since the last trip computer reset.
²Distance to service- shows the distance
remaining until the next scheduled service interval.
²Tire Pressure- shows the tire pressure in each
tire.
²Blank screen- the EVIC compass/temperature/
trip computer VFD is turned off.
The EVIC is capable of displaying the following
alert messages, which are accompanied by an audible
announcement consisting of a series of beeps:
²TURN SIGNALS ON (with vehicle graphic)-
Indicates that a turn signal has remained on for
about 1.6 kilometers (one mile).
²PERFORM SERVICE- Indicates that a cus-
tomer programmable service interval distance has
been reached.
²DOOR OPEN (one or more, with vehicle
graphic)- Indicates that a door is open or not fully
closed.
²LIFTGATE OPEN (with vehicle graphic)-
Indicates that the liftgate is open or not fully closed.
²LIFTGLASS OPEN (with vehicle graphic)-
Indicates that the liftglass is open or not fully closed.²COOLANT LEVEL LOW (with vehicle
graphic)- Indicates that the coolant level in the
engine coolant reservoir is low.
²XX LOW PRESSURE (with vehicle graphic)
- Indicates that the air pressure in the selected tire
is low.
²WASHER FLUID LOW (with vehicle
graphic)- Indicates that the fluid level in the
washer fluid reservoir is low.
The EVIC ªMenuº push button provides the vehicle
operator with a user interface, which allows the
selection of several optional customer programmable
electronic features to suit individual preferences.
Refer toELECTRONIC VEHICLE INFORMA-
TION CENTER PROGRAMMINGin the Service
Procedures section of this group for more information
on the customer programmable feature options.
If the vehicle is equipped with the optional mem-
ory system, the EVIC will display the following mem-
ory system messages:
²MEMORY #X POSITION SET (X = Driver 1
or Driver 2)- This message appears in the EVIC
display each time the memory system is successfully
programmed. It is accompanied by an audible
announcement chime tone.
²MEMORY SYSTEM DISABLED- The memory
system is automatically disabled while the driver
side seat belt is fastened and/or while the automatic
transmission gear selector is in any position except
Park or Neutral. This message appears in the EVIC
display as a reminder when a memory switch push
button is depressed while the memory system is dis-
abled. If the REMOTE LINKED TO MEMORY cus-
tomer programmable feature has been selected, this
message will also appear when the Unlock button of
the Remote Keyless Entry (RKE) transmitter is
depressed while the memory system is disabled.
If the vehicle is equipped with the optional Univer-
sal Transmitter transceiver, the EVIC will also dis-
play messages and an icon indicating when the
Universal Transmitter is being trained, which of the
three transmitter buttons is transmitting, and when
the transceiver is cleared.
If the vehicle is equipped with the optionalTire
Pressure Monitoring System, the EVIC will also
display messages and an icon indicating when the
tire air pressure falls below a given set-point, and
which of the five tires is transmitting the low pres-
sure warning, and when the condition is cleared.
Refer to the Tires/Wheels section of this manual for
complete Tire Pressure Monitoring System descrip-
tion. Refer to this section of the service manual for
EVIC modules function description for the Tire Pres-
sure Monitoring.
Data input for all EVIC functions, including VFD
dimming level, is received through PCI data bus
WJMESSAGE SYSTEMS 8M - 7
ELECTRONIC VEHICLE INFO CENTER (Continued)

data bus messages are being received for initial oper-
ation. Initiate the self-diagnostic test as follows:
(1) With the ignition switch in the Off position,
simultaneously depress and hold the C/T button and
the Reset button.
(2) Turn the ignition switch to the On position.
(3) Continue to hold both buttons depressed until
the EVIC software version information is displayed,
then release both buttons.
(4) Following completion of these tests, the EVIC
module will display one of the following messages:
a.Pass Self Test- Momentarily depress and
release the Reset button to return to the compass/
temperature/trip computer display mode. The EVIC
module is working properly.
b.Failed Self Test- The EVIC module has an
internal failure. The EVIC module is faulty and must
be replaced.
c.Not Receiving J1850 Message- The EVIC
module is not receiving proper message input
through the PCI data bus. This can result from one
or more faulty electronic modules in the vehicle, or
from a faulty PCI data bus. The use of a DRB scan
tool and the proper Diagnostic Procedures manual
are required for further diagnosis.
NOTE: If the compass functions, but accuracy is
suspect, it may be necessary to perform a variation
adjustment. This procedure allows the compass
unit to accommodate variations in the earth's mag-
netic field strength, based on geographic location.
Refer to Compass Variation Adjustment in the Stan-
dard Procedures section of this group.
NOTE: If the compass reading displays a blank, and
only ªCALº appears in the display, demagnetizing
may be necessary to remove excessive residual
magnetic fields from the vehicle. Refer to Compass
Demagnetizing in the Standard Procedures section
of this group.
STANDARD PROCEDURE - TIRE PRESSURE
SYSTEM TEST
The following test can be used to verify two func-
tions. One, that the tire pressure sensors are trans-
mitting properly and two, the EVIC module is
receiving these transmissions accordingly.
(1) Retrain the tire sensors (Refer to 22 - TIRES/
WHEELS/TIRE PRESSURE MONITORING/SEN-
SOR - STANDARD PROCEDURE). The tire sensors
must be retrained in order to set the proper trans-
mitting time cycle (twice a minute), failure to retrain
the sensors will cause a much slower transmitting
time cycle (once a hour).(2) Using the STEP button on the overhead con-
sole, scroll to the blank display, then press the
RESET button for five seconds, a beep will sound
indicating the start of this test. The vehicle icon and
transmission counters will now be displayed, (same
display as individual tire pressure except counters
replace tire pressure values).
(3) Upon entering the test mode, the EVIC will
clear the sensor counter and each time a sensor sig-
nal for a road tire is received, the EVIC will update
the counter value (vehicle must be driven at 25 mph
to transmit). The counter values should all read the
same value. If any of the road tires indicate a differ-
ent value than another tire sensor, this is a sign of a
problem. Replace the appropriate tire sensor and
retest the system. This test will continue until any of
the overhead console buttons are pressed or the igni-
tion is turned off.
NOTE: Pressing the RESET button during the test
will sound a beep and reset all the counter values
back to zero.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(3) Remove the four screws that secure the Elec-
tronic Vehicle Information Center (EVIC) module to
the overhead console housing (Fig. 5).
(4) Remove the EVIC module from the overhead
console housing.
INSTALLATION
(1) Position the EVIC module onto the overhead
console housing.
(2) Install and tighten the four screws that secure
the EVIC module to the overhead console housing.
Tighten the screws to 0.9 N´m (8 in. lbs.).
(3) Install the overhead console onto the headliner
(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
INSTALLATION).
(4) Reconnect the battery negative cable.
NOTE: If a new EVIC module has been installed, the
compass will have to be calibrated and the variance
set. Refer to Compass Variation Adjustment and
Compass Calibration in the Service Procedures sec-
tion of this group for the procedures.
8M - 10 MESSAGE SYSTEMSWJ
ELECTRONIC VEHICLE INFO CENTER (Continued)

This vehicle also offers several customer program-
mable features, which allows the selection of several
optional electronic features to suit individual prefer-
ences. (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE/ELECTRONIC VEHICLE INFO CENTER -
DESCRIPTION). Customer programmable feature
options affecting the power door lock system include:
²Auto Door Locks- Automatically locks all of
the vehicle doors and the liftgate when the vehicle
reaches a speed of about 24 kilometers-per-hour (15
miles-per-hour) with 10% throttle tip-in.
²Auto Unlock on Exit- Automatically unlocks
all of the vehicle doors and the liftgate when the
driver side front door is opened, if the vehicle is
stopped and the transmission gear selector is in the
Park or Neutral positions. This feature is linked to
the Auto Door Locks feature, and will only occur one
time following each Auto Door Lock event.
The power lock system for this vehicle can also be
operated remotely using the standard equipment
Remote Keyless Entry (RKE) system radio frequency
transmitters. (Refer to 8 - ELECTRICAL/POWER
LOCKS - DESCRIPTION - REMOTE KEYLESS
ENTRY SYSTEM).
The components of the power lock system include:
²Driver Door Module (DDM)
²Passenger Door Module (PDM)
²PCI Bus Messages
²Power Lock Motors
Certain functions and features of the power lock
system rely upon resources shared with other elec-
tronic modules in the vehicle over the Programmable
Communications Interface (PCI) data bus network.
The PCI data bus network allows the sharing of sen-
sor information. This helps to reduce wire harness
complexity, internal controller hardware, and compo-
nent sensor current loads. At the same time, this sys-
tem provides increased reliability, enhanced
diagnostics, and allows the addition of many new fea-
ture capabilities. For proper diagnosis of these elec-
tronic modules or of the PCI data bus network, the
use of a DRBIIItscan tool and the appropriate diag-
nostic information are required.
The other electronic modules that may affect power
lock system operation are as follows:
²Body Control Module (BCM)- (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/BODY CONTROL/CENTRAL TIMER MOD-
ULE - DESCRIPTION).
²Electronic Vehicle Information Center
(EVIC)- (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE/ELECTRONIC VEHICLE INFO CENTER
- DESCRIPTION).
²Powertrain Control Module (PCM)- (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROLMODULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
Hard wired circuitry connects the power lock sys-
tem components to the electrical system of the vehi-
cle. These hard wired circuits are integral to several
wire harnesses, which are routed throughout the
vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the power lock sys-
tem components through the use of a combination of
soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
DESCRIPTION - REMOTE KEYLESS ENTRY
SYSTEM
A Radio Frequency (RF) type Remote Keyless
Entry (RKE) system is standard factory-installed
equipment on this model. The RKE system allows
the use of a remote battery-powered radio transmit-
ter to control the power lock system. The RKE
receiver operates on non-switched battery current
through a fuse in the Power Distribution Center
(PDC), so that the system remains operational,
regardless of the ignition switch position.
In addition to Lock and Unlock buttons, the RKE
transmitters are also equipped with a Panic button.
If the Panic button on the RKE transmitter is
depressed, the horn will sound and the exterior lights
will flash on the vehicle for about three minutes, or
until the Panic button is depressed a second time, if
ignition is in the Off position. A vehicle speed of
about 24 kilometers-per-hour (15 miles-per-hour) will
also cancel the panic event.
The RKE system can also perform other functions
on this vehicle. If the vehicle is equipped with the
optional Vehicle Theft Security System (VTSS), the
RKE transmitter will arm the VTSS when the Lock
button is depressed, and disarm the VTSS when the
Unlock button is depressed. (Refer to 8 - ELECTRI-
CAL/VEHICLE THEFT SECURITY - DESCRIPTION
- VEHICLE THEFT SECURITY SYSTEM). If the
vehicle is equipped with the optional Memory Sys-
tem, each of the two numbered and color-coded RKE
transmitters can be used to recall the stored driver
side front seat position, both outside power rear view
mirror positions, and the radio station presets for the
two assigned drivers. (Refer to 8 - ELECTRICAL/
POWER SEATS - DESCRIPTION - MEMORY SYS-
TEM).
8N - 2 POWER LOCKSWJ
POWER LOCKS (Continued)

The RKE system includes two transmitters when
the vehicle is shipped from the factory, but the sys-
tem can retain the vehicle access codes of up to four
transmitters. The transmitter codes are retained in
the RKE receiver memory, even if the battery is dis-
connected. If an RKE transmitter is faulty or lost,
new transmitter vehicle access codes can be pro-
grammed into the system using a DRBIIItscan tool
and the appropriate diagnostic information.
This vehicle also offers several customer program-
mable features, which allows the selection of several
optional electronic features to suit individual prefer-
ences. (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE/ELECTRONIC VEHICLE INFO CENTER -
DESCRIPTION). Customer programmable feature
options affecting the RKE system include:
²Remote Unlock- Allows the option of having
only the driver side front door unlock when the RKE
transmitter Unlock button is depressed the first time
and the remaining doors and the liftgate unlock
when the button is depressed a second time, or hav-
ing all doors and the liftgate unlock upon the first
depression of the RKE transmitter Unlock button.
²Remote Linked to Memory- If the vehicle is
equipped with the Memory System, this feature
allows the option of having the RKE transmitter
Unlock button activate the recall of the stored set-
tings, or having the recall function assigned solely to
the memory switch on the driver side front door trim
panel.
²Sound Horn on Lock- Allows the option of
having the horn sound a short chirp as an audible
verification that the doors have locked, or having no
audible verification.
²Flash Lights with Lock- Allows the option of
having the lights flash as an optical verification that
the doors have locked, or having no optical verifica-
tion.
This group covers the following components of the
RKE system:
²RKE Receiver
²RKE Transmitter
Certain functions and features of the RKE system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
PCI data bus network allows the sharing of sensor
information. This helps to reduce wire harness com-
plexity, internal controller hardware, and component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities. For diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRBIIItscan
tool and the appropriate diagnostic information are
required.The other electronic modules that may affect RKE
system operation are as follows:
²Body Control Module (BCM)- (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/BODY CONTROL/CENTRAL TIMER MOD-
ULE - DESCRIPTION).
²Driver Door Module (DDM)- (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/DOOR MODULE - DESCRIPTION).
²Electronic Vehicle Information Center
(EVIC)- (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE/ELECTRONIC VEHICLE INFO CENTER
- DESCRIPTION).
²Passenger Door Module (PDM)- (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/DOOR MODULE - DESCRIPTION).
²Powertrain Control Module (PCM)- (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
Hard wired circuitry connects the RKE system
components via the PDM to the electrical system of
the vehicle. These hard wired circuits are integral to
several wire harnesses, which are routed throughout
the vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the RKE system com-
ponents through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
COMBINATION FLASHER
The combination flasher is a smart relay that func-
tions as both the turn signal system and the hazard
warning system flasher. The combination flasher con-
tains active electronic Integrated Circuitry (IC) ele-
ments. This flasher can be energized by the BCM to
flash all of the park/turn signal/front side marker
lamps as an optical alert for the RKE panic function
and, if the Flash Lights with Lock programmable fea-
ture is enabled, as an optical verification for the RKE
lock event. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/COMBINATION FLASHER
- DESCRIPTION).
HORN RELAY
The horn relay is a electromechanical device that
switches battery current to the horn when the horn
switch grounds the relay coil. The horn relay is
located in the Power Distribution Center (PDC) in
WJPOWER LOCKS 8N - 3
POWER LOCKS (Continued)

²Ten-way power drivers and passenger seats
with Memory- This power seat option is standard
on Overland models and optional on Limited models.
This option includes a six-way adjustable seat cush-
ion track with power seat back recliners and power
lumbar supports. Heated Seats are standard with
this option.
Refer toHeated Seat Systemfor more informa-
tion on the heated seat option. Refer toMemory
Systemin the Memory System section of this group
for more information on the memory system.
The power seat system includes the following com-
ponents:
²Power lumbar adjuster (ten-way power seat
only)
²Power lumbar switch (ten-way power seat only)
²Power seat recliner (ten-way power seat only)
²Power seat switch
²Power seat track.
Refer toPower Seatin Wiring Diagrams for com-
plete circuit diagrams. Following are general descrip-
tions of the major components in the power seat/
memory seat system.
DESCRIPTION - MEMORY SYSTEM
An electronic memory system is standard equip-
ment on the Limited model. The memory system is
able to store and recall the driver side power seat
positions (including the power recliner position), and
both outside power mirror positions for two drivers.
For vehicles with a radio connected to the Program-
mable Communications Interface (PCI) data bus net-
work, the memory system is also able to store and
recall up to twenty - ten AM and ten FM - radio sta-
tion presets for two drivers. The memory system also
will store and recall the last station listened to for
each driver, even if it is not one of the twenty preset
stations.
The memory system will automatically return to
all of these settings when the corresponding num-
bered and color-coded button (Driver 1 - Black, or
Driver 2 - Gray) of the memory switch on the driver
side front door trim panel is depressed, or when the
doors are unlocked using the corresponding num-
bered and color-coded (Driver 1 - Black, or Driver 2 -
Gray) Remote Keyless Entry (RKE) transmitter. A
customer programmable feature of the memory sys-
tem allows the RKE recall of memory features to be
disabled in cases where there are more than two
drivers of the vehicle.
The memory system also has a customer program-
mable easy exit feature that will move the driver
seat rearward 55 millimeters (two inches) or to the
end of its travel, whichever occurs first, when the key
is removed from the ignition switch lock cylinder.A Memory Seat Module (MSM) or Memory Heated
Seat Module (MHSM) are used on this model to con-
trol and integrate the many electronic functions and
features included in the memory system. On vehicles
equipped with the heated seat system option, the
MHSM also controls the functions and features of
that system.
The memory system includes the following compo-
nents:
²Memory seat module (or memory heated seat
module)
²Memory switch
²Position potentiometers on both outside power
mirrors
²Position potentiometers on the driver side power
seat track and power seat recliner motors.
²Radio receiver (if PCI data bus capable).
Certain functions and features of the memory sys-
tem rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
PCI data bus network allows the sharing of sensor
information. This helps to reduce wire harness com-
plexity, internal controller hardware, and component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities. For diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRBtscan
tool and the proper Diagnostic Procedures manual
are recommended.
The other electronic modules that may affect mem-
ory system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
²Driver Door Module (DDM)- Refer toDoor
Modulein Electronic Control Modules for more
information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console Systems for more infor-
mation.
²Passenger Door Module (PDM)- Refer to
Door Modulein Electronic Control Modules for
more information.
²Powertrain Control Module (PCM)- Refer to
Powertrain Control Modulein Electronic Control
Modules for more information.
²Radio Receiver- Refer toRadio Receiverin
Audio Systems for more information.
Refer toHeated Seat Systemfor more informa-
tion on this system. Refer toRemote Keyless Entry
Systemin Power Lock Systems for more information
on the RKE system. Refer toPower Mirrorin
Power Mirror Systems for more information on the
WJPOWER SEAT SYSTEM 8N - 19
POWER SEAT SYSTEM (Continued)