body control module JEEP GRAND CHEROKEE 2002 WJ / 2.G Repair Manual

wired between a body ground, the Body Control Mod-
ule (BCM) and the rear wiper motor module through
the liftgate and body wire harnesses.
The liftgate flip-up glass ajar switch cannot be
adjusted or repaired and, if faulty or damaged, the
liftgate flip-up glass latch unit must be replaced.
(Refer to 23 - BODY/DECKLID/HATCH/LIFTGATE/
TAILGATE/FLIP-UP GLASS LATCH - REMOVAL)
for the service procedures. For complete circuit dia-
grams, refer to the appropriate wiring information.
DESCRIPTION - LIFTGATE AJAR SWITCH
The two liftgate ajar switches are integral to the
two liftgate latch mechanisms. The two liftgate ajar
switches are actuated by the liftgate latch mecha-
nisms, and are hard wired with each other between a
body ground and the Body Control Module (BCM)
through the liftgate and body wire harnesses.
The liftgate ajar switches cannot be adjusted or
repaired and, if faulty or damaged, the liftgate latch
unit must be replaced. (Refer to 23 - BODY/DECK-
LID/HATCH/LIFTGATE/TAILGATE/LATCH -
REMOVAL) for the service procedures. For complete
circuit diagrams, refer to the appropriate wiring
information.
OPERATION
OPERATION - DOOR AJAR SWITCH
The front door ajar switches close a path to ground
for the DDM or the PDM when a front door is
opened, and opens the ground path when a front door
is closed. The rear door ajar switches close a path to
ground for the BCM when a rear door is opened, and
opens the ground path when a rear door is closed.
The DDM, PDM, or BCM read the switch status then
send the proper switch status messages to other
modules over the Programmable Communications
Interface (PCI) data bus network. The door ajar
switch status message is used by the BCM as an
input for Vehicle Theft Security System (VTSS) oper-
ation.
OPERATION - FLIP UP GLASS AJAR SWITCH
The liftgate flip-up glass ajar switch can close a
path to ground for the BCM and the rear wiper
motor module when the liftgate flip-up glass is
opened, and opens the ground path when the liftgate
flip-up glass is closed. The rear wiper motor module
uses the liftgate flip-up glass ajar switch input to
control the rear wiper operation, and will park the
rear wiper blade if this input indicates that the lift-
gate flip-up glass is ajar. The BCM reads the switch
status then sends the proper switch status message
to other modules over the Programmable Communi-cations Interface (PCI) data bus network. The liftgate
flip-up glass ajar switch status message is used by
the BCM as an input for Vehicle Theft Security Sys-
tem (VTSS) operation.
OPERATION - LIFTGATE AJAR SWITCH
Each of the liftgate ajar switches can close a path
to ground for the BCM when the liftgate is opened,
and opens the ground path when the liftgate is
closed. The BCM reads the switch status then sends
the proper switch status message to other modules
over the Programmable Communications Interface
(PCI) data bus network. The liftgate ajar switch sta-
tus message is used by the BCM as an input for
Vehicle Theft Security System (VTSS) operation.
DIAGNOSIS AND TESTING - DOOR AJAR
SWITCH
The following diagnosis and testing is only
for the chime functions. For interior lamp diag-
nosis, refer to the appropriate wiring informa-
tion.The driver door ajar switch is hard wired to the
Driver Door Module (DDM). The DDM communicates
the switch status to the other modules in the vehicle
on the Programmable Communications Interface
(PCI) data bus network. The following test will diag-
nose a faulty driver door ajar switch and circuits. For
complete circuit diagrams, refer to the appropriate
wiring information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Check that the interior lighting switch on the
control stalk of the left multi-function switch is not
in the dome lamp disable position. Open the driver
side front door and note whether the interior lamps
light. They should light. If OK, refer to Key-In Igni-
tion Switch in the Diagnosis and Testing section of
this group for further diagnosis of the chime warning
system. If not OK, go to Step 2.
(2) Disconnect and isolate the battery negative
cable. Remove the trim panel from the driver front
door and disconnect the 4-way door wire harness con-
nector from the front door latch connector. Check for
continuity between the ground circuit of the 4-way
door wire harness connector and a good ground.
There should be continuity. If OK, go to Step 3. If not
OK, repair the ground circuit.
8L - 30 LAMPS/LIGHTING - INTERIORWJ
DOOR AJAR SWITCH (Continued)

messages. The EVIC module uses its internal pro-
gramming and all of its data inputs to calculate and
display the requested data. If the data displayed is
incorrect, perform the self-diagnostic tests as
described in this group. If these tests prove inconclu-
sive, the use of a DRBIIItscan tool and the proper
Diagnostic Procedures manual are recommended for
further testing of the EVIC module and the PCI data
bus.
The EVIC module cannot be repaired, and is avail-
able for service only as a unit. This unit includes the
push button switches and the plastic housed module.
If any of these components are faulty or damaged,
the complete EVIC module must be replaced. The
incandescent bulbs used for EVIC push button back-
lighting and the display lens are available for service
replacement.
ELECTRONIC VEHICLE INFORMATION CENTER
CHIME
The Electronic Vehicle Information Center (EVIC)
uses the chime warning system for two different
kinds of support. In addition to requesting chime
tones from the Body Control Module (BCM) as tactile
beep support, the EVIC is programmed to send chime
request messages over the Programmable Communi-
cations Interface (PCI) data bus when it detects the
following conditions:
²Door Open Warning- A door is open above a
critical speed [about 16 kilometers-per-hour (10
miles-per-hour) for the driver side front door, or
about 5 kilometers-per-hour (3 miles-per-hour) for
any other door].
²Liftgate Open Warning- The liftgate is open
above a critical speed [about 5 kilometers-per-hour (3
miles-per-hour)].
²Liftglass Open Warning- The liftgate flip-up
glass is open above a critical speed [about 5 kilome-
ters-per-hour (3 miles-per-hour)].
²Low Coolant Level Warning- The coolant
level in the engine coolant reservoir is low.
²Perform Service Alert- An audible alert that
a ªPerform Serviceº reminder message is being dis-
played by the EVIC.
²Turn Signal On Warning- A turn signal
remains on for about 1.6 kilometers (one mile).
²Washer Fluid Low Warning- The fluid level
in the washer reservoir is low.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the EVIC. (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE/ELECTRONIC VEHICLE INFO CENTER
- DESCRIPTION) for more information on the EVIC.
COMPASS
While in the compass/temperature mode, the com-
pass will display the direction in which the vehicle is
pointed using the eight major compass headings
(Examples: north is N, northeast is NE). The self-cal-
ibrating compass unit requires no adjusting in nor-
mal use. The only calibration that may prove
necessary is to drive the vehicle in one circle at 5 to
8 kilometers-per-hour (3 to 5 miles-per-hour), on level
ground, in not less than 20 seconds. This will reori-
ent the compass unit to its vehicle.
The compass unit also will compensate for magne-
tism the body of the vehicle may acquire during nor-
mal use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral pro-
cession flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Mag-
netic bit drivers used on the fasteners that hold the
overhead console assembly to the roof header can
also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this group may be
required to restore proper compass operation.
TEMPERATURE
The outside ambient temperature is displayed in
whole degrees. The temperature display can be tog-
gled from Fahrenheit to Celsius by selecting the
desired U.S./Metric option from the customer pro-
grammable features as described inELECTRONIC
VEHICLE INFORMATION CENTER PROGRAM-
MINGin the Standard Procedures section of this
group. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the temperature display several minutes to
respond to a major temperature change, such as driv-
ing out of a heated garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the Body Control Module (BCM) unit memory. When
the ignition switch is turned to the On position
again, the EVIC will display the memory tempera-
ture for one minute; then update the display to the
current average temperature reading within five
minutes.
The temperature function is supported by an ambi-
ent temperature sensor. The sensor is mounted out-
side the passenger compartment near the front and
center of the vehicle, and is hard wired to the Body
Control Module (BCM). The BCM sends temperature
status messages to the EVIC module over the PCI
data bus network. The ambient temperature sensor
is available as a separate service item.
8M - 8 MESSAGE SYSTEMSWJ
ELECTRONIC VEHICLE INFO CENTER (Continued)

OPERATION
The EVIC has access to both non-switched and
ignition switched sources of battery current so that
some of its features remain operational at any time,
while others may only operate with the ignition
switch in the On position. When the ignition switch
is turned to the On position, the EVIC module VFD
will return to the last function being displayed before
the ignition was turned to the Off position.
The compass/temperature display is the normal
EVIC display. With the ignition switch in the On
position, momentarily depressing and releasing the
C/T (compass/temperature) push button switch will
cause the EVIC to return to the compass/tempera-
ture/trip computer display mode from any other
mode. While in the compass/temperature/trip com-
puter display mode, momentarily depressing and
releasing the Step push button will step through the
available trip computer display options.
The EVIC trip computer features several functions
that can be reset. The functions that can be reset
are: average fuel economy, trip odometer and elapsed
time. With the ignition switch in the On position and
with one of the functions of the trip computer that
can be reset currently displayed, depressing the
Reset push button twice within three seconds will
perform a global reset, and all of the trip computer
information that can be reset will be reset to zero.
With the ignition switch in the On position and the
function that is to be reset currently displayed,
momentarily depressing and releasing the Reset
push button once will perform a local reset, and only
the value of the displayed function will be reset to
zero. A global or local reset will only occur if the
function currently displayed is a function that can be
reset. The distance to service function can also be
reset using the local reset method, but it will reset
back to the Service Interval distance that is set in
the EVIC programmable features mode. Refer to
ELECTRONIC VEHICLE INFORMATION CEN-
TER PROGRAMMINGin the Service Procedures
section of this group for more information on setting
the Service Interval.
For more information on the features, control func-
tions and setting procedures for the EVIC module,
see the owner's manual in the vehicle glove box.
DIAGNOSIS AND TESTING - ELECTRONIC
VEHICLE INFORMATION CENTER
If the problem with the Electronic Vehicle Informa-
tion Center (EVIC) is a temperature reading of 130É
F or -40ÉF shown in the compass/temperature dis-
play, refer toAmbient Temperature Sensor Diag-
nosis and Testingin this group. If the problem with
the EVIC is an inaccurate or scrambled display, refer
toSelf-Diagnostic Testin this group. If the prob-lem with the EVIC is incorrect Vacuum Fluorescent
Display (VFD) dimming levels, use a DRBtscan tool
and the proper Diagnostic Procedures manual to test
for the correct dimming message inputs being
received from the Body Control Module (BCM) over
the Programmable Communications Interface (PCI)
data bus. If the problem is a no-display condition,
use the following procedures. For complete circuit
diagrams, refer toOverhead Consolein Wiring
Diagrams.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the fused B(+)
fuse in the PDC as required.
(3) Check the fused ignition switch output (run/
start) fuse in the junction block. If OK, go to Step 4.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) fuse in the junction block. If OK,
go to Step 5. If not OK, repair the open fused ignition
switch output (run/start) circuit to the ignition switch
as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the overhead console. Check for continuity
between the ground circuit cavity of the roof wire
harness connector for the EVIC module and a good
ground. There should be continuity. If OK, go to Step
6. If not OK, repair the open ground circuit to ground
as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
roof wire harness connector for the EVIC module. If
OK, go to Step 7. If not OK, repair the open fused
B(+) circuit to the fused B(+) fuse in the junction
block as required.
(7) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) circuit cavity of the roof wire har-
ness connector for the EVIC module. If OK, refer to
Self-Diagnostic Testbelow for further diagnosis of
the EVIC module and the PCI data bus. If not OK,
repair the open fused ignition switch output (run/
start) circuit to the fuse in the junction block as
required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
EVIC module is operating properly, and that all PCI
WJMESSAGE SYSTEMS 8M - 9
ELECTRONIC VEHICLE INFO CENTER (Continued)

AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the Elec-
tronic Vehicle Information Center (EVIC) through
ambient temperature messages received from the
Body Control Module (BCM) over the Programmable
Communications Interface (PCI) data bus network.
The BCM receives a hard wired input from the ambi-
ent temperature sensor. The ambient temperature
sensor is a variable resistor mounted to a bracket
that is secured with a screw to the right side of the
headlamp mounting module grille opening, behind
the radiator grille and in front of the engine compart-
ment.
Refer toBody Control Modulein Electronic Con-
trol Modules. For complete circuit diagrams, refer to
the appropriate wiring information. The ambient
temperature sensor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the BCM. The resistance in the sensor
changes as temperature changes, changing the tem-
perature sensor signal circuit voltage to the BCM.
Based upon the resistance in the sensor, the BCM
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The BCM then sends the
proper ambient temperature messages to the EVIC
over the PCI data bus.
The temperature function is supported by the
ambient temperature sensor, a wiring circuit, the
Body Control Module (BCM), the Programmable
Communications Interface (PCI) data bus, and a por-
tion of the Electronic Vehicle Information Center
(EVIC) module. If any portion of the ambient temper-
ature sensor circuit fails, the BCM will self-diagnose
the circuit. A temperature reading of 130É F will
appear in the EVIC display in place of the tempera-
ture when the sensor circuit is shorted. A tempera-
ture reading of ±40É F will appear in the EVIC
display in place of the temperature when the sensor
circuit is open.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Electronic Vehicle Information Center
in this group. For complete circuit diagrams, refer to
the appropriate wiring information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336.6 kilohms. At 60É C (140É F), the sensor
resistance is 2.49 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the 2-way ambient temperature sensor
wire harness connector and the 22-way Body Control
Module (BCM) wire harness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the 2-way ambient tempera-
ture sensor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the 22-way BCM wire harness con-
nector. There should be continuity. If OK, go to Step
4. If not OK, repair the open sensor return circuit or
ambient temperature sensor signal circuit to the
ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the 2-way ambient temperature sensor wire harness
connector. Check for continuity between the sensor
return circuit cavity of the 22-way BCM wire harness
connector and a good ground. There should be no
continuity. If OK, go to Step 5. If not OK, repair the
shorted sensor return circuit as required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the 22-way
BCM wire harness connector and a good ground.
There should be no continuity. If OK, refer toDiag-
nosis and Testing - Electronic Vehicle Informa-
tion Centerin this group. If not OK, repair the
shorted ambient temperature sensor signal circuit as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
8M - 12 MESSAGE SYSTEMSWJ

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)

the engine compartment. This relay can be energized
by the BCM to sound the horns as an audible alert
for the RKE panic function and, if the Sound Horn
on Lock programmable feature is enabled, as an
audible verification for the RKE lock event. (Refer to
8 - ELECTRICAL/HORN/HORN RELAY - DESCRIP-
TION).
LOW BEAM HEADLAMP RELAY
The low beam headlamp relay is a electromechan-
ical device that switches battery current to the head-
lamp low beams when the BCM grounds the relay
coil. The low beam headlamp relay is located in the
junction block in the passenger compartment. This
relay can be energized by the BCM to flash the head-
lamp low beams as an optical alert for the RKE panic
function. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/HEADLAMP - DESCRIPTION).
DESCRIPTION - LIFTGATE FLIP-UP GLASS
POWER RELEASE SYSTEM
A power operated liftgate flip-up glass release sys-
tem is standard factory installed equipment on this
model. The liftgate flip-up glass power release system
allows the flip-up glass latch to be released electri-
cally by depressing a switch located on the bottom of
the liftgate license plate lamp housing unit, above
the license plate on the outside of the liftgate.
The liftgate flip-up glass release system operates
on non-switched battery current supplied through a
fuse in the junction block so that the system remains
functional, regardless of the ignition switch position.
However, a limit switch that is integral to the liftgate
latch actuator unit opens to prevent the flip-up glass
latch from being actuated when the liftgate latch is
locked.
The liftgate flip-up glass power release system
includes the following components:
²Liftgate Flip-Up Glass Limit Switch- The
liftgate flip-up glass limit switch is integral to the
liftgate latch unit. (Refer to 23 - BODY/DECKLID/
HATCH/LIFTGATE/TAILGATE/LATCH - REMOVAL)
and (Refer to 23 - BODY/DECKLID/HATCH/LIFT-
GATE/TAILGATE/LATCH - INSTALLATION).
²Liftgate Flip-Up Glass Release Motor- The
liftgate flip-up glass release motor is integral to the
liftgate flip-up glass latch unit. (Refer to 23 - BODY/
DECKLID/HATCH/LIFTGATE/TAILGATE/FLIP-UP
GLASS LATCH - REMOVAL) and (Refer to 23 -
BODY/DECKLID/HATCH/LIFTGATE/TAILGATE/
FLIP-UP GLASS LATCH - INSTALLATION).
²Liftgate Flip-Up Glass Release Switch- The
liftgate flip-up glass release switch is integral to the
liftgate license plate lamp housing. (Refer to 23 -
BODY/DECKLID/HATCH/LIFTGATE/TAILGATE/
FLIP-UP GLASS SWITCH - REMOVAL) and (Referto 23 - BODY/DECKLID/HATCH/LIFTGATE/TAIL-
GATE/FLIP-UP GLASS SWITCH - INSTALLATION).
Hard wired circuitry connects the liftgate flip-up
glass power release system components to the electri-
cal 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
liftgate flip-up glass power release system compo-
nents 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.OPERATION
OPERATION - POWER LOCK SYSTEM
The Passenger Door Module (PDM) contains the
power door lock control logic and a power lock switch.
The Driver Door Module (DDM) contains a power
lock switch and controls the output to the driver side
front door power lock motor, while the PDM controls
the output to the power lock motors for the remain-
ing doors and the liftgate.
When the power lock switch on the DDM is used to
lock or unlock the doors, the DDM sends a control
output to the driver side front door power lock motor
and sends lock or unlock request messages to the
PDM over the Programmable Communications Inter-
face (PCI) data bus. The PDM responds to these mes-
sages by sending control outputs to the power lock
motors of the remaining doors and the liftgate. When
the power lock switch on the PDM is used to lock or
unlock the doors, the PDM sends control outputs to
the power lock motors in the passenger side front
door, both rear doors and the liftgate, then sends lock
or unlock request messages to the DDM over the Pro-
grammable Communications Interface (PCI) data
bus. The DDM responds to these messages by send-
ing control outputs to the power lock motor of the
driver side front door.
In order to support the auto door locks and unlock
on exit features, if enabled, the power lock system
logic in the PDM needs to know the door ajar switch
status, vehicle speed, and transmission gear selector
lever position. The passenger side front door ajar
switch is the only hard wired input to the PDM. The
PDM obtains the remaining information from mes-
sages it receives from other electronic modules over
the PCI data bus network.
8N - 4 POWER LOCKSWJ
POWER LOCKS (Continued)

²If the power lock system functions with the RKE
transmitter, but not with one or both power lock
switches, proceed to diagnosis of the door modules.
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/DOOR MODULE - DIAGNOSIS
AND TESTING).
²If the driver side power lock switch operates
only the driver side front door power lock motor, but
all other power lock motors operate with the passen-
ger side power lock switch or the RKE transmitter,
use a DRBIIItscan tool and the appropriate diagnos-
tic information to diagnose the Programmable Com-
munications Interface (PCI) data bus.
²If only one power lock motor fails to operate
with both power lock switches and the RKE trans-
mitter, proceed to diagnosis of the power lock motor.
(Refer to 8 - ELECTRICAL/POWER LOCKS/POWER
LOCK MOTOR - DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY SYSTEM
Following are tests that will help to diagnose the
Remote Keyless Entry (RKE) system. However, these
tests may not prove conclusive in the diagnosis of
this system. In order to obtain conclusive testing of
the RKE system, the Programmable Communications
Interface (PCI) data bus network and all of the elec-
tronic modules that provide inputs to, or receive out-
puts from the RKE system components must be
checked.
The most reliable, efficient, and accurate means to
diagnose the RKE system requires the use of a
DRBIIItscan tool and the appropriate diagnostic
information. The DRBIIItscan tool can provide con-
firmation that the PCI data bus is functional, that all
of the electronic modules are sending and receiving
the proper messages on the PCI data bus, and that
the RKE receiver is being sent the proper radio fre-
quency signals by the RKE transmitters to perform
its RKE system functions.
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.
PRELIMINARY DIAGNOSIS
As a preliminary diagnosis for the RKE system,
note the system operation while you perform both the
Lock and Unlock functions with the power lock
switches and with the Remote Keyless Entry (RKE)
transmitter. Then, proceed as follows:
²If the entire power lock system fails to function
with either the power lock switches or the RKE
transmitter, check the fused B(+) fuse in the PowerDistribution Center. If the fuse is OK, proceed to the
diagnosis for the door modules. (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/
DOOR MODULE - DIAGNOSIS AND TESTING).
²If the power lock system functions with both
power lock switches, but not with the RKE transmit-
ter, proceed to the diagnosis for the RKE transmitter.
(Refer to 8 - ELECTRICAL/POWER LOCKS/RE-
MOTE KEYLESS ENTRY TRANSMITTER - DIAG-
NOSIS AND TESTING).
²If the driver side power lock switch operates
only the driver side front door power lock motor, but
all other power lock motors operate with the passen-
ger side power lock switch or the RKE transmitter,
use a DRBIIItscan tool and the appropriate diagnos-
tic information to diagnose the Programmable Com-
munications Interface (PCI) data bus.
If the problem being diagnosed involves only the
Sound Horn on Lock or the Flash Lights with Locks
features, be certain that these programmable fea-
tures are enabled. If the features are enabled and the
service horn and turn signals still operate, the Body
Control Module (BCM) and the PCI data bus must be
tested. For diagnosis of the BCM or the PCI data
bus, the use of a DRBIII scan tool and the appropri-
ate diagnostic information are required.
DIAGNOSIS AND TESTING - LIFTGATE FLIP-UP
GLASS POWER RELEASE SYSTEM
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.
(1) Check the fused B(+) fuse in the Junction
Block (JB). If OK, go to Step 2. If not OK, repair the
shorted circuit or component as required and replace
the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the JB. If OK, go to Step 3. If not OK, repair the
open fused B(+) circuit to the Power Distribution
Center (PDC) as required.
(3) Disconnect the liftgate wire harness connector
for the liftgate lock motor and flip-up glass limit
switch from the motor and switch connector recepta-
cle. Check for battery voltage at the fused B(+) cir-
cuit cavity of the liftgate wire harness connector for
the liftgate lock motor and flip-up glass limit switch.
If OK, go to Step 4. If not OK, repair the open fused
B(+) circuit between the liftgate lock motor and
flip-up glass limit switch and the JB as required.
(4) Check for continuity between the two liftgate
flip-up glass limit switch terminals. There should be
continuity with the liftgate latch unlocked, and no
continuity with the latch locked. If OK, go to Step 5.
8N - 6 POWER LOCKSWJ
POWER LOCKS (Continued)

If not OK, replace the faulty liftgate latch actuator
(brainplate) unit.
(5) Disconnect the liftgate wire harness connector
for the liftgate flip-up glass release switch from the
switch connector receptacle. With the liftgate latch
unlocked, check for battery voltage at the liftgate
flip-up glass limit switch output circuit cavity of the
liftgate wire harness connector for the release switch.
If OK, go to Step 6. If not OK, repair the open lift-
gate flip-up glass limit switch output circuit between
the release switch and the limit switch as required.
(6) Check for continuity between the two terminals
of the liftgate flip-up glass release switch. There
should be no continuity. Depress the switch, there
should now be continuity. If OK, go to Step 7. If not
OK, replace the faulty liftgate flip-up glass release
switch.
(7) Disconnect the liftgate wire harness connector
for the liftgate flip-up glass latch motor from the
motor connector receptacle. Check for continuity
between the ground circuit cavity of the liftgate wire
harness connector for the latch motor and a good
ground. There should be continuity. If OK, go to Step
8. If not OK, repair the open ground circuit to ground
as required.
(8) With the liftgate latch unlocked and the flip-up
glass release switch depressed, check for battery volt-
age at the liftgate flip-up glass release switch output
circuit cavity of the liftgate wire harness connector
for the latch motor. If OK, replace the faulty liftgate
flip-up glass latch unit. If not OK, repair the open
liftgate flip-up glass release switch output circuit
between the latch motor and the release switch as
required.
DOOR CYLINDER LOCK
SWITCH
DESCRIPTION
The driver cylinder lock switch is integral to the
key lock cylinder inside the driver side front door.
The driver cylinder lock switch is a resistive multi-
plexed switch that is hard wired between a body
ground and the Driver Door Module (DDM) through
the front door wire harness. It maintains a path to
ground, and changes voltages through an internal
resistor when the lock cylinder is rotated to the lock
or unlock position.
The driver cylinder lock switch cannot be adjusted
or repaired and, if faulty or damaged, the driver side
front door lock cylinder unit must be replaced. (Refer
to 23 - BODY/DOOR - FRONT/LOCK CYLINDER -
REMOVAL) and (Refer to 23 - BODY/DOOR -
FRONT/LOCK CYLINDER - INSTALLATION). Refer
to the appropriate wiring information. The wiringinformation 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.
OPERATION
The driver cylinder lock switch is actuated by the
key lock cylinder when the key is inserted in the lock
cylinder and turned to the unlock position. The
driver cylinder lock switch maintains a path to
ground and changes voltages through an internal
resistor for the DDM when the driver door key lock
cylinder is in the lock or unlock position. The DDM
reads the switch status through an internal pull-up,
then sends the proper switch status messages to
other electronic modules over the Programmable
Communications Interface (PCI) data bus network.
The driver cylinder lock switch unlock status mes-
sage is used by the BCM as an input for Vehicle
Theft Security System (VTSS) operation and interior
lighting.
POWER LOCK MOTOR
DESCRIPTION
Power operated front door, rear door, and liftgate
locking mechanisms are standard equipment on this
model. The lock mechanisms are actuated by a
reversible electric motor mounted within each door
and the liftgate. The power lock motors for the doors
are integral to the door latch units. The liftgate
power lock motor is a separate unit secured to the
latch brainplate near the center of the liftgate and
operates the liftgate latch lock mechanism through a
connecting linkage rod.
The power lock motors for the four doors cannot be
adjusted or repaired and, if faulty or damaged, the
entire door latch unit must be replaced. The liftgate
power lock motor cannot be adjusted or repaired and,
if faulty or damaged, the entire liftgate latch actua-
tor (brainplate) unit must be replaced.
OPERATION
The driver side front door power lock motor is con-
trolled by the Driver Door Module (DDM). The
remaining power door lock motors and the liftgate
power lock motor are controlled by the Passenger
Door Module (PDM). A positive and negative battery
connection to the two motor terminals will cause the
power lock motor plunger to move in one direction.
Reversing the current through these same two con-
nections will cause the power lock motor plunger to
move in the opposite direction.
WJPOWER LOCKS 8N - 7
POWER LOCKS (Continued)

POWER MIRRORS
TABLE OF CONTENTS
page page
POWER MIRRORS
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - POWER
MIRRORS...........................12
AUTOMATIC DAY/NIGHT MIRROR
DESCRIPTION
DESCRIPTION - REAR VIEW MIRROR.....12
DESCRIPTION - OUTSIDE REAR VIEW
MIRROR............................13
OPERATION
OPERATION - REAR VIEW MIRROR.......13
OPERATION - OUTSIDE REAR VIEW
MIRROR............................13
DIAGNOSIS AND TESTING - AUTOMATIC DAY
/ NIGHT MIRROR......................13POWER FOLD-AWAY MIRROR - EXPORT
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - POWER
FOLD-AWAY MIRROR - EXPORT..........14
REMOVAL.............................14
POWER MIRROR SWITCH
DESCRIPTION.........................15
OPERATION...........................15
SIDEVIEW MIRROR
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - SIDEVIEW
MIRROR............................16
POWER MIRRORS
DESCRIPTION
Driver and passenger side power operated outside
rear view mirrors are standard factory-installed
equipment on this model. The power mirror system
allows the driver to adjust both outside mirrors elec-
trically from the driver seat position by operating a
switch on the driver side front door trim panel. The
power mirror system receives non-switched battery
current through a fuse in the Power Distribution
Center (PDC) so that the power mirrors remain oper-
ational, regardless of the ignition switch position.
The standard equipment power operated outside
rear view mirrors are also equipped with the heated
mirror system, which will only operate when the
ignition switch is in the On position and the rear
window defogger switch is turned on. When the rear
window defogger switch is in the On position, electric
heater grids on the rear window glass and behind
both outside rear view mirror glasses are energized.
These electric heater grids produce heat to help clear
the rear window glass and outside rear view mirrors
of ice, snow, or fog. (Refer to 8 - ELECTRICAL/
HEATED MIRRORS - DESCRIPTION) for more
information on this feature.
A driver side automatic dimming outside mirror
that dims the mirror to reduce the glare of bright
lights approaching the vehicle from behind, and a
memory system that automatically positions the
power mirrors for two different drivers are optionalfactory-installed equipment on this model. (Refer to 8
- ELECTRICAL/POWER MIRRORS/AUTOMATIC
DAY / NIGHT MIRROR - DESCRIPTION) for more
information. (Refer to 8 - ELECTRICAL/POWER
SEATS - DESCRIPTION) for more information.
This group covers the following components of the
power mirror system:
²Power mirrors
²Power mirror switch.
Certain functions and features of the power mirror
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 diagnosis of these electronic
modules or of the PCI data bus network, the use of a
DRB scan tool and the proper Diagnostic Procedures
manual are recommended.
The other electronic modules that may affect power
mirror system operation are as follows:
²Body Control Module (BCM)(Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/BODY CONTROL/CENTRAL TIMER MODUL
- DESCRIPTION) for more information.
²Driver Door Module (DDM)(Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
WJPOWER MIRRORS 8N - 11