2002 JEEP GRAND CHEROKEE Head light

READING LAMP
DESCRIPTION
The overhead console in this vehicle is equipped
with two individual reading and courtesy lamps.Each
lamp has its own switch, bulb, reflector and lens; but
both lamps share a common lamp housing within the
overhead console.
The overhead console reading and courtesy lamps
operate on battery current that is provided at all
times, regardless of the ignition switch position. The
ground feed for the lamps is switched through the
integral reading and courtesy lamp switches or
through the door jamb switches.
The reading and courtesy lamp lenses and the
lamp housing and reflector unit are serviced only as
a unit with the overhead console housing.The reading
and courtesy lamp switches, bulb holders and wiring
are only available as part of the overhead console
wire harness.
For service of the reading and courtesy lamp bulbs,
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
INTERIOR/READING LAMP - REMOVAL). For diag-
nosis of the reading and courtesy lamps, refer to the
appropriate wiring information.
OPERATION
All reading and courtesy lamps located in the over-
head console are activated by the door jamb switches.
When all of the doors are closed, these lamps can be
individually activated by depressing the correspond-
ing lens. When any door is open, depressing the lamp
lenses to activate the lamp switches will not turn the
lamps off.
REMOVAL
(1) Remove the overhead console.
(2) Rotate the console until the bulb is visible (Fig.
2).
(3) Grasp the bulb and remove from the socket.
INSTALLATION
(1) Push the bulb into the bulb socket.
(2) Install the console on the headliner and roof
panel.
(3) Align the screw hole and install the screw.
TRANS RANGE INDICATOR
ILLUMINATION
DESCRIPTION
The Transmission Range Indicator Lamp, mounted
on the floor console, uses electroluminescent technol-ogy as the light source. This lamp requires a 120 volt
AC signal that is provided by a power converter
included as part of the assembly. The module is not
serviceable separately. Because of a potential shock
hazard, diagnostic testing of the lamp assembly
should be avoided. Refer to TRANSMISSION, Range
Selector Assembly Removal and Installation.
VANITY LAMP
REMOVAL
(1) Fold down the visor.
(2) Using a small flat blade, and staring at the
base of the lamp assembly, carefully pry the base of
the lamp from the visor.
(3) Disconnect the vanity lamp visor and remove
the lamp from the vehicle.
INSTALLATION
(1) Position the lamp at the visor and connect the
wire connector.
(2) Press the lamp in place.
Fig. 2 Overhead Console Reading Lamp Bulb
1 - BULB
8L - 32 LAMPS/LIGHTING - INTERIORWJ

PROGRAMMABLE FEATURES
²LANGUAGE?-The options include English,
Francaise, Deutsch, Italiana, or Espanol. The default is
English. All EVIC display nomenclature, including the
trip computer functions, warning messages and the pro-
grammable features appear in the selected language.
²DISPLAY U.S. OR METRIC?- The options
include U.S. and M. The default is U.S. This feature
toggles the trip computer temperature, fuel economy
and odometer display readings between U.S. and
metric units of measure. It also changes the odome-
ter display in the instrument cluster.
²AUTO DOOR LOCKS?- The options include
Yes and No. The default is Yes. When Yes is selected,
all doors and the liftgate lock automatically when
vehicle speed reaches 25 kilometers-per-hour (15
miles-per-hour). If YES is selected, a second program-
mable feature appears,AUTO UNLOCK ON EXIT?
- The options again include Yes and No. The default
is No. When Yes is selected, following each Auto Door
Lock event all doors and the liftgate will automati-
cally unlock when the driver door is opened, if the
vehicle is stopped and the transmission gear selector
is in Park or Neutral. The Auto Door Unlock event
will only occur once following each Auto Door Lock
event.
²REMOTE UNLOCK- The options include
Driver Door 1st and All Doors. The default is Driver
Door 1st. When Diver Door 1st is selected, only the
driver door unlocks when the Unlock button of the
Remote Keyless Entry (RKE) transmitter is
depressed once. The Unlock button of the RKE trans-
mitter must be depressed twice to unlock all doors
and the liftgate. When All Doors is selected, all doors
and the liftgate unlock when the Unlock button of
the RKE transmitter is depressed once.
²REMOTE LINKED TO MEMORY?- This pro-
grammable feature 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 memory system will recall the Driver 1
or Driver 2 memory settings assigned to the RKE
transmitter being used to unlock the vehicle. When
No is selected, the memory system will only recall
memory settings when the Driver 1 or Driver 2 push
buttons of the memory switch on the driver side front
door trim panel are depressed.
²SOUND HORN ON LOCK?- The options
include Yes and No. The default is No. When Yes is
selected, a short horn chirp will provide an audible
confirmation when the RKE receiver recognizes a
valid Lock signal from an RKE transmitter. When No
is selected, no horn chirp will occur with the RKE
Lock event. This feature may be selected indepen-
dent of theFLASH LIGHTS WITH LOCKS?pro-
grammable feature.²FLASH LIGHTS WITH LOCKS?- The options
include Yes and No. The default is Yes. When Yes is
selected, a single flash of the hazard warning lamps
will provide an optical confirmation when the RKE
receiver recognizes a valid Lock signal from an RKE
transmitter, and two flashes of the same lamps will
occur when the RKE receiver recognizes a valid
Unlock signal from an RKE transmitter. When No is
selected, no lamp flash will occur with the RKE Lock
or Unlock event. This feature may be selected inde-
pendent of theSOUND HORN ON LOCK?pro-
grammable feature.
²HEADLAMP DELAY =- The options include
Off, 30 Sec, 60 Sec, and 90 Sec. The default is 90 Sec.
When a time interval is selected, the headlamps will
remain on for that length of time when the head-
lamps are turned off after the ignition is turned off,
or if the Auto mode is selected on vehicles with the
Auto Headlamps option. When Off is selected, the
headlamp delay feature is disabled.
²HEADLAMPS ON WITH WIPERS?- This pro-
grammable feature only applies to vehicles equipped
with the optional Auto Headlamps. The options
include Yes and No. The default is No. When Yes is
selected, the headlamps will turn on automatically
when the windshield wipers are turned on. The head-
lamps will turn off when the wipers are turned off,
as long as the headlamp switch is in the Auto or Off
positions. When No is selected, the headlamps will
only turn on if manually selected or if the Auto mode
is selected and the outside ambient light levels dic-
tate that they should be on.
²SERVICE INTV. =- The options include from
1000 to 12000 kilometers in 1000 kilometer incre-
ments (2000 to 7500 miles in 500 mile increments).
The default is 12000 kilometers (7500 miles). The
selected distance becomes the interval at which the
Perform Service warning message will be displayed
by the EVIC. If a new distance is selected, a second
programmable feature appears,RESET SERVICE
DISTANCE?- The options include No and Yes. The
default is Yes. When Yes is selected, the accumulated
distance since the last previous Perform Service
warning message will be reset to zero because the
service interval has been changed. When No is
selected, the distance until the next Perform Service
warning message is reduced by the accumulated dis-
tance since the last previous message.
²LOW FUEL CHIME?- The options include Yes
and No. The default is Yes. When Yes is selected, a
single chime will sound as an audible alert whenever
the instrument cluster low fuel warning lamp lights.
The chime will sound only once per ignition cycle.
When No is selected, only the low fuel warning lamp
in the instrument cluster will light and no chime will
sound.
WJMESSAGE SYSTEMS 8M - 3
OVERHEAD CONSOLE (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)

NOTE: If the vehicle is equipped with the Tire Pres-
sure Monitoring (TPM) System, and the overhead
console electronics module is removed or replaced,
the TPM system will need to be retrained. Refer to
the Tires/Wheels section of this manual for the pro-
cedure.
UNIVERSAL TRANSMITTER
DESCRIPTION
The Grand Cherokee Limited model has a Univer-
sal Garage Door Opener (UGDO) transceiver as stan-
dard factory-installed equipment. The UGDO is
optional on Laredo models. The UGDO transceiver is
integral to the Electronic Vehicle Information Center
(EVIC), which is located in the overhead console. The
only visible component of the UGDO are the three
transmitter push buttons centered between the four
EVIC push buttons located just rearward of the
EVIC display screen in the overhead console. The
three UGDO transmitter push buttons are identified
with one, two or three dots so that they be easily
identified by sight.
Each of the three UGDO transmitter push buttons
controls an independent radio transmitter channel.
Each of these three channels can be trained to trans-
mit a different radio frequency signal for the remoteoperation of garage door openers, motorized gate
openers, home or office lighting, security systems or
just about any other device that can be equipped
with a radio receiver in the 288 to 410 MegaHertz
(MHz) frequency range for remote operation. The
UGDO is capable of operating systems using either
rolling code or non-rolling code technology.
The EVIC module displays messages and a small
house-shaped icon with one, two or three dots corre-
sponding to the three transmitter buttons to indicate
the status of the UGDO. The EVIC messages are:
²Cleared Channels- Indicates that all of the
transmitter codes stored in the UGDO have been suc-
cessfully cleared.
²Training- Indicates that the UGDO is in its
transmitter learning mode.
²Trained- Indicates that the UGDO has success-
fully acquired a new transmitter code.
²Transmit- Indicates that a trained UGDO
transmitter button has been depressed and that the
UGDO is transmitting.
The UGDO cannot be repaired, and is available for
service only as a unit with the EVIC module. This
unit includes the push button switches and the plas-
tic module. If any of these components are faulty or
damaged, the complete EVIC module must be
replaced.
OPERATION
The universal transmitter operates on a non-
switched source of battery current so the unit will
remain functional, regardless of the ignition switch
position. For more information on the features, pro-
gramming procedures and operation of the universal
transmitter, see the owner's manual in the vehicle
glove box.
DIAGNOSIS AND TESTING - UNIVERSAL
TRANSMITTER
If the Universal Transmitter is inoperative, but the
Electronic Vehicle Information Center (EVIC) is oper-
ating normally, see the owner's manual in the vehicle
glove box for instructions on training the Transmit-
ter. Retrain the Transmitter with a known good
transmitter as instructed in the owner's manual and
test the Transmitter operation again. If the unit is
still inoperative, replace the faulty Transmitter and
EVIC module as a unit. If both the Transmitter and
the EVIC module are inoperative, refer toElec-
tronic Vehicle Information Center Diagnosis
and Testingin this group for further diagnosis. For
complete circuit diagrams, refer toWiring Dia-
grams.
Fig. 5 Top of Overhead Console
1 - OVERHEAD CONSOLE HOUSING
2 - EVIC MODULE
3 - ILLUMINATION LAMPS
4 - SCREWS (4)
WJMESSAGE SYSTEMS 8M - 11
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)

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)

See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the power lock system.
OPERATION - REMOTE KEYLESS ENTRY
SYSTEM
The Passenger Door Module (PDM) contains the
RKE system control logic and the RKE receiver.
When the RKE receiver recognizes a Lock, Unlock or
Panic message from a valid RKE transmitter, the
RKE receiver provides that input to the PDM. The
PDM circuitry and programming responds by sending
the proper messages to the other electronic modules
over the Programmable Communications Interface
(PCI) data bus.
When an RKE lock message is received, the doors
and the liftgate lock, the interior lighting fades to off,
the horn chirps (if this feature is enabled), the exte-
rior lamps flash (if this feature is enabled) and, if the
vehicle is so equipped, the Vehicle Theft Security
System (VTSS) is armed. When an RKE unlock mes-
sage is received, the driver side front door (or all
doors and the liftgate if this feature is enabled)
unlock, the interior lighting is turned on and, if the
vehicle is so equipped, the VTSS is disarmed. If the
vehicle is equipped with the Memory System and the
RKE Linked to Memory feature is enabled, the RKE
unlock message also recalls the driver seat, outside
mirror and radio settings assigned to the RKE trans-
mitter that sent the unlock signal.
When an RKE panic message is received, it causes
the exterior lamps (including the headlights) to flash,
and the horn to pulse for about three minutes, or
until a second panic message is received. A vehicle
speed of about 24 kilometers-per-hour (15 miles-per-
hour) will also cancel the panic event.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the RKE system.
OPERATION - LIFTGATE FLIP-UP GLASS
POWER RELEASE SYSTEM
When the liftgate mounted flip-up glass release
switch is depressed, battery current is directed to the
electric release motor that is integral to the flip-up
glass latch located inside the liftgate. When the
release motor is energized the latch releases and the
flip-up glass can be opened. A liftgate flip-up glass
limit switch is integral to the liftgate latch actuator
mechanism. The limit switch automatically enables
or disables the liftgate flip-up glass power release cir-
cuitry, depending upon the position of the liftgate
latch lock mechanism. When the liftgate latch is
unlocked, the limit switch closes and battery current
is available at the release switch. When the liftgatelatch is locked , the limit switch opens, and the
release switch is disabled.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the liftgate flip-up glass power release system.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER LOCK
SYSTEM
Following are tests that will help to diagnose the
hard wired components and circuits of the power lock
system. However, these tests may not prove conclu-
sive in the diagnosis of this system. In order to
obtain conclusive testing of the power lock system,
the Programmable Communications Interface (PCI)
data bus network and all of the electronic modules
that provide inputs to, or receive outputs from the
power lock system components must be checked.
The most reliable, efficient, and accurate means to
diagnose the power lock system requires the use of a
DRBIIItscan tool and the proper Diagnostic Proce-
dures manual. The DRBIIItscan tool can provide
confirmation that the PCI data bus is functional, that
all of the electronic modules are sending and receiv-
ing the proper messages on the PCI data bus, and
that the power lock motors are being sent the proper
hard wired outputs by the door modules for them to
perform their power lock 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 power lock sys-
tem, note the system operation while you actuate
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 Power
Distribution Center. If the fuse is OK, proceed to
diagnosis of 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 diagnosis of the Remote Keyless Entry
(RKE) system. (Refer to 8 - ELECTRICAL/POWER
LOCKS - DIAGNOSIS AND TESTING - REMOTE
KEYLESS ENTRY SYSTEM).
WJPOWER LOCKS 8N - 5
POWER LOCKS (Continued)