electronic control modules CHRYSLER VOYAGER 2003 Owner's Guide

Refer to the description of the heated seat switch
later in this section for additional information.
Hard wired circuitry connects the heated seat sys-
tem components to each other through 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 differ-
ent methods. These circuits may be connected to each
other, to the vehicle electrical system and to the
heated seat system components through the use of a
combination of soldered splices and splice block con-
nectors. Refer to Wiring for complete system wiring
schematics. The wiring information also includes the
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 heated seat system components operate on
battery current received through a fuse in the Inte-
grated Power Module (IPM) on a fused ignition
switch output (run) circuit so that the system will
only operate when the ignition switch is in the On
position. The heated seat system will be turned Off
automatically whenever the ignition switch is turned
to any position except On. Also, the heated seat sys-
tem will not operate when the surface temperature of
the seat cushion cover at either heated seat sensor is
above the designed temperature set points of the sys-
tem. See the owner's manual in the vehicle glove box
for more information on the features, use and opera-
tion of the heated seat system.
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM
The most reliable, efficient, and accurate means to
diagnose the heated seat 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 heated seat modules are receiving the
proper hard wired inputs from and relaying the
proper hard wired outputs to the Body Control Mod-
ule in order to perform its functions. Refer toWiring
Diagramsfor complete wiring schematics. The wir-
ing information also includes the 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 connec-
tors, splices and grounds.
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 2). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazard, rear window
wiper and washer switches. The heated seat switches
each provide a resistor multiplexed signal to its
respective Heated Seat Module (HSM) through sepa-
rate hard wired circuits. Each switch has an Off,
Low, and High position so that both the driver and
the front seat passenger can select a preferred seat
heating mode. Each switch has two Light-Emitting
Diodes (LED) which light to indicate that the heater
for the seat is turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the high position LED indi-
Fig. 2 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)
ProCarManuals.com

In order to access and test the heated seat ele-
ments it will be necessary to remove the appropriate
front seat retaining bolts and lay the seat rearward,
up against one of the rear seats. It is not necessary
to disconnect the seat electrical connectors, just use
care not to damage the attached wire harnesses
while testing.
NOTE: When checking heated seat elements for
continuity, be certain to move the heating element
being checked. Moving the element, such as sitting
in the seat will eliminate the possibility of an inter-
mittent open in the element which would only be
evident if the element was in a certain position.
Failure to check the element in various positions
could result in an incomplete test.
SEAT CUSHION ELEMENT
(1) From under the vehicle, remove the appropri-
ate seats four retaining nuts.
(2) From inside the vehicle, pull the seat up, off
the mounting studs and lay it back, up against one of
the rear seats.
(3) Locate the heated seat module, attached to the
bottom of the seat cushion pan. Remove the heated
seat module from the seat cushion pan. Do not dis-
connect the electrical connectors at this time.
(4) Locate the green 4-way electrical connector,
connected to the heated seat module. Disconnect the
green 4-way connector from the heated seat module.
(5) Check for continuity between the two outboard
circuit cavities of the wire harness connector (Pins
1&4). There should be continuity. If OK, refer to
Heated Seat Module Diagnosis and Testing in the
Electronic Control Modules section of the service
manual for complete system testing procedures. If
not OK, install a replacement heated seat cushion
element. Refer to the procedure in this section.
SEAT BACK ELEMENT
(1) From under the vehicle, remove the appropri-
ate seats four retaining nuts.
(2) From inside the vehicle, pull the seat up and
off the mounting studs and lay it back, up against
one of the rear seats.
(3) Locate the heated seat module, attached to the
bottom of the seat cushion pan. Remove the heated
seat module from the seat cushion pan. Do not dis-
connect the electrical connectors at this time.
(4) Locate the gray 2-way electrical connector, con-
nected to the heated seat module. Disconnect the
2-way connector from the heated seat module.
(5) Check for continuity between the two circuit
cavities of the 2-way wire harness connector. There
should be continuity. If OK, refer to Heated Seat
Module Diagnosis and Testing in the Electronic Con-trol Modules section of the service manual for com-
plete system testing procedures. If not OK, install a
replacement heated seat back element. Refer to the
procedure in this section.
REMOVAL
Do not remove the OEM heating element from the
seat or seat back cushion/trim covers. The original
element is permanently attached and cannot be
removed without permanent damage. The service
replacement heating element is designed to be
applied directly on the seat cushion.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the appropriate seat cushion or seat
back trim cover. Refer to the Body section of the ser-
vice manual for the procedures.
(3) Disconnect the inoperative heated seat cushion
or seat back element electrical connectors.
(4) Locate the wires leading from the inoperative
heating element and cut them off flush with the edge
of the original heating element.
INSTALLATION
(1) Peel off the adhesive backing on the back of the
replacement heating element and stick directly on
the foam cushion.
CAUTION: During the installation of the replace-
ment heating element, be careful not to fold or
crease the element assembly. Folds or creases will
cause premature failure.
(2) Connect the new heating element electrical
connectors (Fig. 5).
(3) Connect the negative battery cable.
(4) Verify heated seat system operation.
(5) Install the appropriate seat cushion or seat
back trim cover. Make certain the seat wire harness
is correctly routed through the seat and seat back.
The excess wire between the cushion and back ele-
ments should be securely tucked between the rear of
the cushion foam and the rear carpet flap of the trim
cover.
HEATED SEAT SENSOR
DESCRIPTION
Two heated seat sensors are used per vehicle, one
in each front seat cushion heating element. The
heated seat temperature sensor is a Negative Tem-
perature Coefficient (NTC) thermistor.
The heated seat sensors cannot be repaired or
adjusted and if found to be faulty, the complete
heated seat cushion element must be replaced.
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT ELEMENTS (Continued)
ProCarManuals.com

HORN SYSTEM TEST
CONDITION POSSIBLE CAUSE CORRECTION
HORN SOUNDS CONTINUOUSLY.
NOTE: IMMEDIATELY UNPLUG HORN
RELAY IN THE IPM.(1) FAULTY HORN RELAY. (1) REFER TO HORN RELAY TEST.
(2) HORN CONTROL
CIRCUIT TO RELAY
SHORTED TO GROUND.(2) CHECK TERMINAL 85 IN IPM
FOR CONTINUITY TO GROUND. IF
CONTINUITY TO GROUND
INDICATES:
(A) STEERING WHEEL HORN
SWITCH/LEAD SHORTED TO
GROUND.
(B) WIRING HARNESS SHORTED
TO GROUND. FIND THE SHORT
AND REPAIR AS NECESSARY.
(3) PINCHED HORN
SWITCH WIRE UNDER
DRIVER AIRBAG MODULE.(3) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(4) FAULTY HORN SWITCH. (4) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(5) FAULTY CLOCKSPRING. (5) REPLACE CLOCKSPRING.
(6) FAULTY FRONT
CONTROL MODULE.(6) REFER TO ELECTRONIC
CONTROL MODULES/FRONT
CONTROL MODULE.
HORN SOUND INTERMITTENTLY AS
THE STEERING WHEEL IS TURNED.(1) HORN RELAY
CONTROL CIRCUIT X3 IS
SHORTED TO GROUND
INSIDE STEERING
COLUMN OR WHEEL.(1) REMOVE DRIVER AIRBAG
MODULE AND/OR WHEEL. CHECK
FOR RUBBING OR LOOSE
WIRE/CONNECTOR, REPAIR AS
NECESSARY.
(2) PINCHED HORN
SWITCH WIRE UNDER
DRIVER AIRBAG MODULE.(2) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(3) FAULTY HORN SWITCH. (3) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(4) FAULTY CLOCKSPRING. (4) REPLACE CLOCKSPRING.
8H - 2 HORNRS
HORN SYSTEM (Continued)
ProCarManuals.com

CONDITION POSSIBLE CAUSE CORRECTION
HORN DOES NOT SOUND (1) CHECK FUSE 8 IN
INTELLIGENT POWER
MODULE.(1) REPLACE FUSE IF BLOWN
REPAIR AS NECESSARY.
(2) NO VOLTAGE AT HORN
RELAY TERMINALS 30 &
86, AND FUSE IS OK.(2) NO VOLTAGE, REPAIR THE
CIRCUIT AS NECESSARY.
(3) OPEN CIRCUIT FROM
TERMINAL 85 OF THE
HORN RELAY TO HORN
SWITCH, X3 CIRCUIT.(3) REPAIR CIRCUIT AS
NECESSARY.
(4) FAULTY OR DAMAGED
HORN.(4) VOLTAGE AT HORN WHEN
HORN SWITCH IS PRESSED,
REPLACE HORN.
(5) FAULTY HORN SWITCH. (5) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(6) FAULTY CLOCKSPRING. (6) REPLACE CLOCKSPRING.
(7) FAULTY FRONT
CONTROL MODULE.(7) REFER TO ELECTRONIC
CONTROL MODULES/FRONT
CONTROL MODULE.
FUSE BLOWS WHEN HORN SOUNDS (1) SHORT CIRCUIT IN
HORN OR HORN WIRING.(1) REMOVE HORN RELAY, CHECK
FOR SHORTED HORN OR HORN
WIRING. DISCONNECT HORN WIRE
HARNESS TO ISOLATE SHORT
AND REPAIR AS NECESSARY.
(2) FAULTY CLOCKSPRING. (2) REPLACE CLOCKSPRING.
FUSE BLOWS WITHOUT BLOWING
HORN(1) SHORT CIRCUIT. (1) REMOVE RELAY, INSTALL NEW
FUSE, IF FUSE DOES NOT BLOW
REPLACE HORN RELAY. IF FUSE
BLOWS WITH RELAY REMOVED,
CHECK FOR SHORT TO GROUND
WITH OHMMETER ON CIRCUIT
BETWEEN TERMINALS 30 & 86
AND THE FUSE TERMINAL. REPAIR
AS NECESSARY.
(2) FAULTY CLOCKSPRING. (2) REPLACE CLOCKSPRING.
HORN
DIAGNOSIS AND TESTING - HORN
HORN
(1) Disconnect wire connector at horn.
(2) Using a voltmeter, connect one lead to ground
terminal and the other lead to the positive wire ter-
minal (Fig. 1).
(3) Depress the horn switch, battery voltage
should be present.
(4) If no voltage, refer toHORNS WILL NOT
SOUND. If voltage is OK, go to step Step 5.(5) Using ohmmeter, test ground wire for continu-
ity to ground.
(6) If no ground repair as necessary.
(7) If wires test OK and horn does not sound,
replace horn.HORNS SOUND CONTINUOUSLY
CAUTION: Continuous sounding of horns may
cause relay to fail.
The horn switch (membrane) sometimes can be the
cause without the switch being depressed.
(1) Remove the horn relay from the intelligent
power module.
RSHORN8H-3
HORN SYSTEM (Continued)
ProCarManuals.com

also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this section may be
required to restore proper compass operation.
DESCRIPTION - TEMPERATURE
All the available overhead consoles on this model
include Temperature information. The temperature
displays the outside ambient temperature in whole
degrees. The temperature display can be toggled
from Fahrenheit to Celsius by selecting the desired
U.S./Metric option from the customer programmable
features. 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 electronic control modules (CT, CMTC, EVIC)
memory. When the ignition switch is turned to the
On position again, the electronic module will display
the memory temperature for one minute; then update
the display to the current average temperature read-
ing 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 Front
Control Module (FCM). The FCM sends temperature
status messages to the module over the J1850 PCI
data bus circuit.
Following are general descriptions of the major
components used in the overhead console. Refer to
Wiring Diagrams for complete circuit schematics.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSelf-Diag-
nostic Testbelow. If the problem with the overhead
console is incorrect Vacuum Fluorescent Display
(VFD) dimming levels, use a DRB IIItscan tool and
the proper Diagnostic Procedures manual to test for
the correct dimming message inputs being received
from the Body Control Module (BCM) or Front Con-
trol Module (FCM) over the J1850 Programmable
Communications Interface (PCI) data bus circuit. If
the problem is a no-display condition, use the follow-
ing procedures. For complete circuit diagrams, refer
toOverhead Consolein the Wiring Diagrams sec-
tion of the service manual.(1) Check the fused B(+) fuse in the integrated
power module. 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 integrated power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the integrated power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the integrated power module. 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 integrated power mod-
ule. 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 electronics 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 electronics mod-
ule. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit to the fused B(+) fuse in the inte-
grated power module 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 electronics module. If OK, refer
toSelf-Diagnostic Test
later this group for further
diagnosis of the electronics module and the J1850
PCI data bus circuit. If not OK, repair the open fused
ignition switch output (run/start) circuit to the fuse
in the integrated power module as required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
electronics module is operating properly, and that all
the J1850 PCI data bus messages are being received
for initial operation. Initiate the self-diagnostic test
as follows:
(1) With the ignition switch in the Off position, on
Electronic Vehicle Information Center (EVIC) and
Compass Mini-Trip Computer (CMTC) equipped vehi-
cles simultaneously depress and hold theSTEP and
the RESET buttons. On Compass Temperature
Module (CT) equipped vehicles depress theC/T and
the US/M push buttons.
8M - 2 MESSAGE SYSTEMSRS
OVERHEAD CONSOLE (Continued)
ProCarManuals.com

US/Mpush button to step through the zone numbers,
until the zone number for your geographic location
appears in the display.
(6) On Electronic Vehicle Information Center
(EVIC) and Compass Mini-Trip Computer (CMTC)
equipped vehicles momentarily depress and release
theRESETpush button to enter the displayed zone
number into the EVIC/CMTC module memory. On
Compass Temperature Module (CT) equipped vehicles
depress theC/Tpush button to enter the displayed
zone number into the electronic module memory.
(7) Confirm that the correct directions are now
indicated by the compass.
REMOVAL - OVERHEAD CONSOLE
(1) Disconnect and isolate the remote negative bat-
tery cable.
(2) Remove the overhead console retaining screw,
located in the front of console.
(3) Using your fingertips, grasp the sides of the
overhead console and pull straight down evenly to
disengage the two snap clips at the rear of the unit.
(4) Lower the overhead console far enough to
access the wire harness connectors.
(5) Disconnect the EVIC, CMTC or CT electronic
module and the reading/courtesy lamps electrical
connector.
(6) Remove the overhead console from the vehicle.
INSTALLATION
(1) Position the overhead console in the vehicle.
(2) Connect the EVIC, CMTC or CT electronic
module and the reading/courtesy lamps electrical
connector.
(3) Using your fingertips, grasp the sides of the
overhead console and push straight up evenly to
engage the two snap clips at the rear of the unit.
CAUTION: DO NOT PRESS ON THE SUNGLASS
STORAGE BIN DOOR. DAMAGE TO THE DOOR MAY
RESULT.
(4) Install the overhead console retaining screw,
located in the front of console. Torque the screw to
1.2 N´m (10 in. lbs.).
(5) Connect the remote negative battery cable.
SPECIAL TOOLS
OVERHEAD CONSOLE
ELECTRONIC VEHICLE INFO
CENTER
DESCRIPTION
The Electronic Vehicle Information Center (EVIC)
is a module located in the overhead console on some
models. The EVIC module features a large Vacuum
Fluorescent Display (VFD) screen for displaying
information, and back-lit push button switches
labeled C/T (compass/thermometer), RESET, STEP,
and MENU.
The EVIC module contains a central processing
unit and interfaces with other electronic modules in
the vehicle over the Programmable Communications
Interface (PCI) J1850 data bus circuit. The PCI data
bus circuit allows the sharing of sensor information.
This helps to reduce wire harness complexity, reduce
internal controller hardware, and reduce component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities.
The EVIC ªMenuº push button provides the vehicle
operator with a user interface, which allows the
selection of several optional customer programmable
electronic features to suit individual preferences.
Refer toELECTRONIC VEHICLE INFORMA-
TION CENTER PROGRAMMINGin the Standard
Procedures section of this group for more information
on the customer programmable feature options.
If the vehicle is equipped with the optional univer-
sal transmitter transceiver, the EVIC will also dis-
play messages and an icon indicating when the
universal transmitter transceiver is being trained,
which of the three transmitter buttons is transmit-
ting, and when the transceiver is cleared.
Data input for all EVIC functions, including VFD
dimming level, is received through the J1850 PCI
data bus circuit. The EVIC module uses its internal
programming 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-
DEGAUSSING TOOL #6029
8M - 6 MESSAGE SYSTEMSRS
OVERHEAD CONSOLE (Continued)
ProCarManuals.com

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.
²RETRAIN TIRE SENSORS?- This program-
mable feature only applies to vehicles equipped with
the optional Tire Pressure Monitoring System. The
options include Yes and No. The default is No. When
Yes is selected, and the menu button is depressed the
EVIC will enter the training mode, starting with the
left front tire.
²POWER ACCESSORY DELAY?- The options
include Yes and No. The default is Yes. When No is
selected, the accessory powered components will turn
off automatically when the ignition key is turned off.
When Yes is selected, the accessory powered compo-
nents will remain on for 45 seconds when the igni-
tion key is turned off.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove overhead console. Refer to Overhead
Console Removal and Installation in this section(Re-
fer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
REMOVAL).
(3) Remove the ten screws holding the EVIC mod-
ule in the overhead console.
(4) Remove EVIC module from console assembly.
NOTE: If the EVIC module is being replaced, the tire
pressure monitoring system (if equipped) must be
retrained. Refer to the Tires/Wheels section of this
manual for detailed instructions.
INSTALLATION
(1) Position the EVIC module in the overhead con-
sole.
(2) Install the ten screws holding the EVIC module
in the overhead console.
(3) Install the overhead console (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION).
(4) Connect the battery negative cable.
NOTE: If the EVIC module is being replaced, the tire
pressure monitoring system (if equipped) must be
retrained. Refer to the Tires/Wheels section of this
manual for detailed instructions.NOTE: If a new EVIC module has been installed, the
compass will have to be calibrated and the variance
set. Refer to compass variation adjustment and
compass calibration in standard procedures.
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The Compass Mini-Trip Computer (CMTC) and
Compass Temperature (CT) computer are modules
located in the overhead console. Vehicles are
equipped with either the CMTC or the CT computers
not both. The CMTC is different in the fact that it is
equipped with the mini-trip feature. The CMTC, CT
consists of a electronic control module with a vacuum
fluorescent display (VFD) and function switches. The
CMTC, CT consists of a electronic module that dis-
plays compass, trip computer (CMTC only), and tem-
perature features. Actuating the STEP push button
(CMTC only) will cause the CMTC to change mode of
operation when ignition is ON. Actuating the STEP
push button (CMTC only) will cause the CMTC to
change mode of operation when ignition is ON.
Example:
²Average miles per gallon (ECO)
²Distance to empty (DTE)
²Instant miles per gallon (ECO)
²Trip odometer (ODO)
²Elapsed time (ET)
²Off
Actuating the C/T push button will cause the
CMTC, CT to change to Compass/Temperature dis-
play.
OPERATION
The Compass Mini-Trip Computer (CMTC), Com-
pass Temperature (CT) module in the overhead con-
sole has buttons used to select various functions. The
CMTC, CT selector buttons will not operate until the
ignition is in the RUN position.
When the ignition switch is first turned to the
RUN position the CMTC, CT display;
²Blanks momentarily
²All segments of the VFD will light for one sec-
ond
²Blanks momentarily
²Returns to the last mode setting selected before
the ignition was last switched OFF.
RSMESSAGE SYSTEMS8M-9
ELECTRONIC VEHICLE INFO CENTER (Continued)
ProCarManuals.com

DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER
Compass Mini-Trip Computer (CMTC) and Com-
pass Temperature (CT) data is obtained from the
Body Control Module (BCM) on the J1850 Data Bus
circuit. The CMTC and CT will display dashes (- -)
for any of the screens it did not receive the bus mes-
sages. The label corresponding to the missing infor-
mation will be lit. If no compass mini-trip computer
data is displayed, check the J1850 Data Bus circuit
communications and the BCM. If the brightness level
is improper check the J1850 Data Bus circuit.
The DRB IIItis recommended for checking the
J1850 Data Bus circuit and the BCM. Perform the
CMTC, CT self diagnosis before replacing the CMTC
or CT module.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove overhead console(Refer to 8 - ELEC-
TRICAL/OVERHEAD CONSOLE - REMOVAL).
(3) Remove the screws holding Compass Mini-Trip
Computer module in the overhead console.
(4) Remove CMTC module from console assembly.
INSTALLATION
(1) Position the compass mini-trip computer mod-
ule in the overhead console.
(2) Install the ten screws holding the compass
mini-trip computer module in the overhead console.
(3) Install the overhead console (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION).
(4) Connect the battery negative cable.
NOTE: If a new EVIC module has been installed, the
compass will have to be calibrated and the variance
set. Refer to compass variation adjustment and
compass calibration in standard procedures.
UNIVERSAL TRANSMITTER
DESCRIPTION
On some RS models a Universal Transmitter trans-
ceiver is standard factory-installed equipment. The
universal transmitter transceiver is integral to the
Electronic Vehicle Information Center (EVIC) and the
Compass Mini-Trip Computer (CMTC) modules,
which is located in the overhead console. The only
visible component of the universal transmitter are
the three transmitter push buttons centered between
the modules push buttons located just rearward of
the display screen in the overhead console. The threeuniversal transmitter push buttons are identified
with one, two or three light indicators so that they be
easily identified by sight or by feel.
Each of the three universal transmitter push but-
tons controls an independent radio transmitter chan-
nel. Each of these three channels can be trained to
transmit a different radio frequency signal for the
remote operation of garage door openers, motorized
gate openers, home or office lighting, security sys-
tems or just about any other device that can be
equipped with a radio receiver in the 286 to 399
MegaHertz (MHz) frequency range for remote opera-
tion. The universal transmitter is capable of operat-
ing systems using either rolling code or non-rolling
code technology.
The electronics module displays messages and a
small house-shaped icon with one, two or three dots
corresponding to the three transmitter buttons to
indicate the status of the universal transmitter. The
EVIC messages are:
²Cleared Channels- Indicates that all of the
transmitter codes stored in the universal transmitter
have been successfully cleared.
²Training- Indicates that the universal trans-
mitter is in its transmitter learning mode.
²Trained- Indicates that the universal transmit-
ter has successfully acquired a new transmitter code.
²Transmit- Indicates that a trained universal
transmitter button has been depressed and that the
universal transmitter is transmitting.
The universal transmitter cannot be repaired, and
is available for service only as a unit with the EVIC
or CMTC modules. If any of these components is
faulty or damaged, the complete EVIC or CMTC
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, test the universal transmitter with
Radio Frequency Detector special tool. If both the
8M - 10 MESSAGE SYSTEMSRS
COMPASS/MINI-TRIP COMPUTER (Continued)
ProCarManuals.com

Transmitter and the EVIC module are inoperative,
refer toElectronic Vehicle Information Center
Diagnosis and Testingin this group for further
diagnosis. For complete circuit diagrams, refer to
Wiring Diagrams. (Fig. 5) as described below:
(1) Turn the Radio Frequency (RF) Detector ON. A
ªchirpº will sound and the green power LED will
light. If the green LED does not light, replace the
battery.
(2) Hold the RF detector within one inch of the
TRAINED universal transmitter and press any of the
transmitters buttons.
(3) The red signal detection LEDs will light and
the tool will beep if a radio signal is detected. Repeat
this test three times.
STANDARD PROCEDURE
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES
(1) Turn off the engine.
(2) Erase the codes by pressing the two outside
buttons. Release the buttons when the display con-
firms the operation (about 20 seconds).
(3) Choose one of the three buttons to train. Place
the hand-held transmitter within one inch of the uni-
versal transmitter and push the buttons on both
transmitters.(4) Release both buttons. Your universal transmit-
ter is now ªtrainedº. To train the other buttons,
repeat Step 3 and Step 4. Be sure to keep your hand-
held transmitter in case you need to retrain the uni-
versal transmitter.
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES
To erase the universal transmitter codes, simply
hold down the two outside buttons until the display
confirms the operation.
NOTE: Individual channels cannot be erased. Eras-
ing the transmitter codes will erase ALL pro-
grammed codes.
REMOVAL
(1) For universal transmitter removal and installa-
tion procedure, (Refer to 8 - ELECTRICAL/OVER-
HEAD CONSOLE/COMPASS/MINI-TRIP
COMPUTER - REMOVAL and INSTALLATION).
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console through ambient temperature messages
received from the Front Control Module (FCM) over
the Programmable Communications Interface (PCI)
J1850 data bus circuit. The FCM receives a hard
wired input from the ambient temperature sensor.
The ambient temperature sensor is a variable resis-
tor 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 compartment.
For more information on the Front Control Module
refer to the Electronic Control Modules section of this
manual. For complete circuit diagrams, refer to the
appropriate wiring information. The ambient temper-
ature 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 Front Control Module. The resis-
tance in the sensor changes as temperature changes,
changing the temperature sensor signal circuit volt-
age to the Front Control Module. Based upon the
resistance in the sensor, the Front Control Module
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The Front Control Module
Fig. 5 RADIO FREQUENCY DETECTOR
1 - SIGNAL DETECTION LED'S
2 - POWER LED
3 - ON/OFF SWITCH
4 - 9V BATTERY
RSMESSAGE SYSTEMS8M-11
UNIVERSAL TRANSMITTER (Continued)
ProCarManuals.com

POWER LIFTGATE SYSTEM
DESCRIPTION
Some vehicles are equipped with an automatic
opening and closing power liftgate system (Fig. 1).
This power liftgate system is a complex system con-
sisting of many components. Some of these compo-
nents are the liftgate gear motor assembly, latch
assembly, lift gear and rod, liftgate control module,
chime/thermistor, full open switch, engage actuator,
pinch sensor, liftgate handle switch, overhead console
switch, key fob switches (Fig. 2), pawl switch and
ratchet switch.
The power liftgate system has its own door control
module, located on the vehicles left body D-pillar
behind the trim panel. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DOOR CON-
TROL MODULE - DESCRIPTION) The power
liftgate gear motor assembly is located just above the
control module. The latch assembly is located in the
bottom center of the power liftgate, below the exte-
rior liftgate handle switch. The power liftgate full
open switch, engage actuator, lift gear and rod are
part of the liftgate gear motor assembly. The pawl
and ratchet switches are part of the latch assembly.
The pinch sensor or sensors are located along theright and left sides of the power liftgate, just above
the body line. The liftgate handle switch is an power
release switch and is located in the rear light bar
assembly, just above the license plate. The overhead
console switch is an power open and close command
switch located in the vehicles overhead console.
Safety is of the utmost concern with the power lift-
gate system. Software technology has enabled the
power liftgate control module to detect resistance to
liftgate travel, which allows the power liftgate to stop
and reverse direction anytime an obstruction is felt
or any of the command switches are operated (only in
closing direction). Battery voltage is supplied to the
power liftgate system through a 40 amp fuse, located
in the Intelligent Power Module (IPM) assembly (Fig.
3). In the unlikely event that the power liftgate sys-
tem develops a fault the power liftgate can still be
operated manually with a key, just like a standard
manual liftgate.
The power liftgate control module communicates
on the J1850 Programmable Communication Inter-
face (PCI) Bus Circuit. Therefore, the power liftgate
control module can generate and store its own Diag-
nostic Trouble Codes (DTC). The vehicles Body Con-
trol Module (BCM) receives and supplies messages to
the power liftgate control module via the PCI bus cir-
cuit. A diagnostic scan tool, such as the DRB IIItis
Fig. 1 POWER LIFTGATE INTRODUCTION
8N - 2 POWER LIFTGATE SYSTEMRS
ProCarManuals.com