2002 JEEP GRAND CHEROKEE glove

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)

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)

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)

DIAGNOSIS AND TESTING - POWER LOCK
MOTOR
Remember, the Driver Door Module (DDM) cir-
cuitry controls the output to the driver side front
door power lock motor. The Passenger Door Module
(PDM) circuitry controls the output to the power lock
motors for the remaining doors and the liftgate.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
(1) Check each power lock motor for correct opera-
tion while moving the power lock switch to both the
Lock and Unlock positions. If all of the power lock
motors are inoperative, go to Step 2. If one power
lock motor is inoperative, go to Step 3.
(2) If all of the power lock motors except the driver
side front door are inoperative, the problem may be
caused by one shorted motor. Disconnecting a shorted
power lock motor from the power lock circuit will
allow the good power lock motors to operate. Discon-
nect the wire harness connector from each PDM-con-
trolled power lock motor, one at a time, and recheck
both the lock and unlock functions by operating the
power lock switch. If all of the PDM-controlled power
lock motors are still inoperative after the above test,
check for a short or open circuit between the power
lock motors and the PDM. If disconnecting one power
lock motor causes the other motors to become func-
tional, go to Step 3 to test the power lock motor that
was last disconnected.
(3) Once it is determined which power lock motor
is inoperative, that motor can be tested as follows.
Disconnect the door or liftgate wire harness connec-
tor from the inoperative power lock motor. Apply 12
volts to the lock and unlock driver circuit cavities of
the power lock motor connector to check its operation
in one direction. Reverse the polarity to check the
motor operation in the opposite direction. If OK,
repair the shorted or open circuits between the lock
motor and the DDM or PDM as required. If not OK,
replace the faulty power lock motor.
POWER LOCK SWITCH
DESCRIPTION
The power lock motors are controlled by a two-way
momentary switch mounted on the trim panel of each
front door. Each power lock switch is illuminated by
a Light-Emitting Diode (LED) that is integral to the
switch paddle.
The driver side front door power lock switch is
integral to the Driver Door Module (DDM), and the
passenger side front door power lock switch is inte-
gral to the Passenger Door Module (PDM). The
power lock switches and their lamps cannot be
adjusted or repaired and, if faulty or damaged, the
entire DDM or PDM unit must be replaced. (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/DOOR MODULE - DESCRIPTION).
OPERATION
The front door power lock switches provide a lock
and unlock signal to the door module circuitry. The
Driver Door Module (DDM) circuitry controls the out-
put to the driver side front door power lock motor,
while the Passenger Door Module (PDM) circuitry
controls the output to the passenger side front door,
both rear door and the liftgate power lock motors.
When the DDM-integrated power lock switch is
actuated, the DDM circuitry sends control outputs to
the driver side front door power lock motor and sends
a message to the PDM over the Programmable Com-
munications Interface (PCI) data bus to control the
output to the passenger side front door, both rear
door and the liftgate power lock motors. When the
PDM-integrated power lock switch is actuated, the
PDM circuitry sends control outputs to the passenger
side front door, both rear door and the liftgate power
lock motors and sends a message to the DDM over
the Programmable Communications Interface (PCI)
data bus to control the output to the driver side front
door power lock motor.
Each power lock switch is illuminated by a Light-
Emitting Diode (LED) when the ignition switch is
turned to the On position. See the owner's manual in
the vehicle glove box for more information on the fea-
tures, use and operation of the power lock switches.
8N - 8 POWER LOCKSWJ
POWER LOCK MOTOR (Continued)

REMOTE KEYLESS ENTRY
MODULE
DESCRIPTION
The Remote Keyless Entry (RKE) receiver is a
radio frequency unit contained within the Passenger
Door Module (PDM). The PDM also contains the pro-
gram logic circuitry for the RKE system. The PDM is
secured with screws to the back of the trim panel
inside the passenger side front door. The RKE
receiver has a memory function to retain the vehicle
access codes of up to four RKE transmitters. The
receiver is designed to retain the transmitter codes in
memory, even if the battery is disconnected.
For diagnosis of the RKE receiver, the PDM, or the
Programmable Communications Interface (PCI) data
bus a DRBIIItscan tool and the appropriate diagnos-
tic information are required. The RKE receiver is
only serviced as a unit with the PDM and, if faulty
or damaged, the entire PDM unit must be replaced.
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/DOOR MODULE - DESCRIP-
TION).
OPERATION
The RKE receiver is energized by one of three mes-
sages from the RKE transmitter: Unlock, Lock, or
Panic. The PDM circuitry responds to these messages
to lock or unlock the power lock motors that it con-
trols. The PDM circuitry also sends Lock, Unlock,
and Panic messages to other electronic modules over
the Programmable Communications Interface (PCI)
data bus. These messages will result in the Driver
Door Module (DDM) locking or unlocking the driver
side front door, and the other electronic modules in
the vehicle responding as their programming dic-
tates.
REMOTE KEYLESS ENTRY
TRANSMITTER
DESCRIPTION
The Remote Keyless Entry (RKE) system Radio
Frequency (RF) transmitter is equipped with three
buttons, labeled Lock, Unlock, and Panic. It is also
equipped with a key ring and is designed to serve as
a key fob. The operating range of the transmitter
radio signal is up to 10 meters (30 feet) from the
RKE receiver.
Each RKE transmitter has a different vehicle
access code, which must be programmed into the
memory of the RKE receiver in the vehicle in order
to operate the RKE system. Two transmitters are
provided with the vehicle, but the RKE receiver canretain the access codes of up to four transmitters in
its memory. (Refer to 8 - ELECTRICAL/POWER
LOCKS/REMOTE KEYLESS ENTRY TRANSMIT-
TER - STANDARD PROCEDURE - RKE TRANS-
MITTER PROGRAMMING).
In addition, the RKE transmitters for vehicles
equipped with the optional Memory System are color-
coded and have a number ª1º or ª2º molded into the
transmitter case to coincide with the ªDriver 1
(Black)º and ªDriver 2 (Gray)º buttons of the memory
switch on the driver side front door trim panel. These
transmitters must also have their access codes pro-
grammed into the RKE receiver so that they coincide
with the ªDriver 1º and ªDriver 2º buttons of the
memory switch. (Refer to 8 - ELECTRICAL/POWER
SEATS - DESCRIPTION - MEMORY SYSTEM).
The RKE transmitter operates on two Panasonic
CR2016 (or equivalent) batteries. Typical battery life
is from one to two years. The RKE transmitter can-
not be repaired and, if faulty or damaged, it must be
replaced.
OPERATION
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the Remote Keyless Entry (RKE) transmitters.
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY TRANSMITTER
(1) Replace the Remote Keyless Entry (RKE)
transmitter batteries. (Refer to 8 - ELECTRICAL/
POWER LOCKS/REMOTE KEYLESS ENTRY
TRANSMITTER - STANDARD PROCEDURE - RKE
TRANSMITTER BATTERIES). Test each of the RKE
transmitter functions. If OK, discard the faulty bat-
teries. If not OK, go to Step 2.
(2) Program the suspect RKE transmitter and
another known good transmitter into the RKE
receiver. Use a DRBIIItscan tool, as described in the
appropriate diagnostic information. (Refer to 8 -
ELECTRICAL/POWER LOCKS/REMOTE KEYLESS
ENTRY TRANSMITTER - STANDARD PROCE-
DURE - RKE TRANSMITTER PROGRAMMING).
(3) Test the RKE system operation with both
transmitters. If both transmitters fail to operate the
power lock system, use a DRBIIItscan tool and the
appropriate diagnostic information for further diag-
nosis of the RKE system. If the known good RKE
transmitter operates the power locks and the suspect
transmitter does not, replace the faulty RKE trans-
mitter.
NOTE: Be certain to perform the RKE Transmitter
Programming procedure again following this test.
This procedure will erase the access code of the
test transmitter from the RKE receiver.
WJPOWER LOCKS 8N - 9

ULES/DRIVER DOOR MODULE - DESCRIPTION)
for more information.
²Passenger Door Module (PDM)(Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/DRIVER DOOR MODULE - DESCRIPTION)
for more information.
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.
OPERATION
The Driver Door Module (DDM) and the Passenger
Door Module (PDM) each contain the power mirror
control logic for the mirror on its respective door. The
DDM also houses the power mirror switch. Each door
module controls the positioning of its respective out-
side mirror through hard wired outputs to that mir-
ror. When the power mirror switch on the DDM is
used to position the passenger side outside mirror,
the DDM sends mirror positioning 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 move the
passenger side mirror accordingly.
Both the PDM and DDM respond to the defogger
switch status messages sent by the Body Control
Module (BCM) over the PCI data bus to control the
electric heater grids of their respective mirrors.
(Refer to 8 - ELECTRICAL/HEATED MIRRORS -
DESCRIPTION) for more information on this fea-
ture.
On models equipped with the optional memory sys-
tem, each door module also receives a hard wired
input from the two power mirror motor position
potentiometers that are integral to each power mir-
ror. Each door module then stores the Driver 1 and
Driver 2 mirror position information for its respective
mirror. When the DDM receives a Driver 1 or Driver
2 memory recall message from the memory switch on
the driver side front door trim panel or from the
Remote Keyless Entry (RKE) receiver in the PDM,
the DDM positions the driver side mirror and sends
a memory recall message back to the PDM over the
PCI data bus to position the passenger side mirror.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the power mirror system.
DIAGNOSIS AND TESTING - POWER MIRRORS
Following are tests that will help to diagnose the
hard wired components and circuits of the power mir-
ror system. However, these tests may not prove con-
clusive in the diagnosis of this system. In order toobtain conclusive testing of the power mirror 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 mirror system components must be checked.
The most reliable, efficient, and accurate means to
diagnose the power mirror system requires the use of
a DRB scan tool and the proper Diagnostic Proce-
dures manual. The DRB scan tool can provide confir-
mation 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, that the
power mirror motors are being sent the proper hard
wired outputs, and that the mirror position potenti-
ometers are returning the proper outputs to the door
modules for them to perform their power mirror sys-
tem functions.
AUTOMATIC DAY/NIGHT
MIRROR
DESCRIPTION
DESCRIPTION - REAR VIEW MIRROR
An automatic day/night mirror system is an avail-
able factory-installed option on this model. The auto-
matic dimming inside day/night rear view mirror
system is a completely self-contained unit that
replaces the standard equipment inside rear view
mirror. This system will automatically change the
reflectance of the inside rear view mirror to protect
the driver from the unwanted headlight glare of
trailing vehicles while driving at night. The auto-
matic day/night inside mirror receives ignition
switched battery current through a fuse in the junc-
tion block, and will only operate when the ignition
switch is in the On position.
Vehicles equipped with the automatic day/night
mirror system are also available with an optional fac-
tory-installed automatic dimming outside rear view
mirror for the driver side of the vehicle. (Refer to 8 -
ELECTRICAL/POWER MIRRORS/SIDEVIEW MIR-
ROR - DESCRIPTION) for more information on this
option.
The automatic day/night mirror sensitivity cannot
be repaired or adjusted. If any component of this unit
is faulty or damaged, the entire automatic day/night
inside rear view mirror unit must be replaced. Refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
8N - 12 POWER MIRRORSWJ
POWER MIRRORS (Continued)

DESCRIPTION - OUTSIDE REAR VIEW MIRROR
An automatic dimming outside rear view mirror is
an available factory-installed option for the driver
side of the vehicle, if the vehicle is also equipped
with the automatic day/night inside rear view mirror.
The automatic dimming outside mirror is completely
controlled by the circuitry of the automatic day/night
inside rear view mirror. The automatic dimming out-
side mirror will automatically change the reflectance
of the driver side outside rear view mirror to protect
the driver from the unwanted headlight glare of
trailing vehicles while driving at night. The auto-
matic dimming outside mirror will only operate when
the ignition switch is in the On position.
The automatic dimming outside mirror sensitivity
cannot be repaired or adjusted. If any component of
this unit is faulty or damaged, the entire automatic
dimming outside mirror unit must be replaced. (Refer
to 8 - ELECTRICAL/POWER MIRRORS/SIDEVIEW
MIRROR - DIAGNOSIS AND TESTING). Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
OPERATION
OPERATION - REAR VIEW MIRROR
The automatic day/night mirror switch allows the
driver a manual control of whether the automatic
dimming feature is operational. This switch is a
momentary rocker-type switch located on the lower
rear-facing surface of the mirror housing. When Auto
is selected, a Light-Emitting Diode (LED) on the mir-
ror housing just to the right of the switch illuminates
to indicate that automatic day/night mirror is turned
on. When Off is selected, the LED is turned off. The
mirror also senses the backup lamp circuit, and will
automatically disable its self-dimming feature when-
ever the transmission gear selector is in the Reverse
position.
A thin layer of electrochromatic material between
two pieces of conductive glass make up the face of
the mirror. Two photocell sensors are used to monitor
light levels and adjust the reflectance of the mirror.
The ambient photocell sensor faces forward, to detect
the outside light levels. The headlamp sensor is
located on the mirror housing just to the left of the
switch and facing rearward, to detect the light level
received at the rear window side of the mirror. When
the difference between the two light levels becomes
too great (the light level received at the rear of themirror is much higher than that at the front of the
mirror), the mirror begins to darken.
On models with an optional driver side automatic
dimming outside mirror, the signal to control the
dimming of that mirror is generated by the auto-
matic day/night inside rear view mirror circuitry.
That signal is then delivered to the driver side out-
side rear view mirror on a hard wired circuit.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the automatic day/night mirror system.
OPERATION - OUTSIDE REAR VIEW MIRROR
The automatic dimming outside mirror is operated
by the same controls and circuitry as the automatic
day/night mirror. When the automatic day/night mir-
ror is turned on or off, the automatic dimming out-
side mirror is likewise turned on or off. Like in the
automatic day/night mirror, a thin layer of electro-
chromatic material between two pieces of conductive
glass make up the face of the automatic dimming
outside mirror. However, the signal to control the
dimming of the outside mirror is generated by the
automatic day/night inside rear view mirror circuitry.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the automatic dimming outside mirror.
DIAGNOSIS AND TESTING - AUTOMATIC DAY /
NIGHT MIRROR
For complete circuit diagrams, refer to the appro-
priate 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 connec-
tors, splices and grounds.
(1) Check the fused ignition switch output (run/
start) fuse in the junction block. If OK, go to Step 2.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(2) 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 3. If not OK, repair the open fused ignition
switch output (run/start) circuit to the ignition switch
as required.
(3) Disconnect the overhead wire harness connec-
tor from the automatic day/night mirror connector
receptacle. Check for battery voltage at the fused
ignition switch output (run/start) circuit cavity of the
overhead wire harness connector for the automatic
day/night mirror. If OK, go to Step 4. If not OK,
repair the open fused ignition switch output (run/
start) circuit to the fuse in the junction block as
required.
WJPOWER MIRRORS 8N - 13
AUTOMATIC DAY/NIGHT MIRROR (Continued)