trip computer CHRYSLER CARAVAN 2005 Service Manual

The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.
OPERATION
The Body Control Module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle's serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.
This network consists of the;
²Powertrain Control Module (PCM)
²Transmission Control Module (TCM)
²Mechanical Instrument Cluster (MIC)
²Occupant Restraint Controller (ORC)
²Compass/Mini-Trip Computer (CMTC)
²Electronic Vehicle Information Center (EVIC)
²Controller Antilock Brake (CAB)
²HVAC Control Module
²Sliding Door Control Modules (driver and pas-
senger side doors)
²Power Liftgate Module (PLG)
²Audio system equipped with RAZ, RBU, RBK,
and RBB radios.
²Sentry Key Remote Entry Module (SKREEM).
²Side Impact Airbag Control Module (SIACM)²Memory Seat Module (MSM)
²Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is
supplied to the module.
The BCM provides the following features:
²Power Door Locks
²Automatic Door Locks
²Battery Protection - The BCM will automatically
turn off all exterior lamps after 3 minutes, and all
interior lamps after 15 minutes after the ignition is
turned off, if they are not turned off by the driver.
²Chime Control
²Compass/Mini-Trip support.
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Headlamp Time Delay (with/without Automatic
Headlamps)
²Illuminated Entry
²Fade to Off Interior Lamps - This feature dims
the interior lighting (courtesy lamps) gradually if the
BCM does not receive any new inputs that would
cause the interior lamps to remain on.
²Pulse Width Modulated Instrument Panel Dim-
ming
²Door Lock Inhibit - This feature disables the
door lock functions if the key is in the ignition and
either front door is ajar. Pressing the Remote Keyless
Entry (RKE) lock/unlock button under these condi-
tions result in normal lock/unlock activation.
The BCM has the ability to LEARN additional fea-
tures in the vehicle, provided the appropriate switch
input and PCI data bus messages are received. Refer
to the LEARNED FEATURES table.
LEARNED FEATURES
FEATURE LEARNING KEY
REAR WIPER CONTROL ON HVAC CONTROL ON
INSTRUMENT PANELPCI BUS MESSAGE RECEIVED FROM HVAC
CONTROL
AUTOMATIC HEADLAMPS PCI MESSAGE FROM OVERHEAD OR HEADLAMP
SWITCH POSITION (AUTO)
REMOTE KEYLESS ENTRY SKREEM MESSAGE RECEIVED FROM MODULE
FRONT FOG LAMPS HEADLAMP SWITCH POSITION (PARK W/FRONT
FOG LAMPS)
POWER SLIDING DOOR PCI IFR RECEIVED FROM MODULE
THE BCM HAS FOUR SWITCH INPUTS FOR THE POWER SLIDING DOOR FEATURE; LOCATED IN THE
OVERHEAD CONSOLE ARE THE LEFT AND RIGHT SIDE SLIDING DOOR SWITCHES TO ACTIVATE EITHER
OR BOTH SLIDING DOORS UNDER THE PROPER CONDITIONS. ALSO ARE B-PILLAR SWITCHES LOCATED
ON THE LEFT AND RIGHT B-PILLAR POSTS.
POWER LIFTGATE PCI IFR RECEIVED FROM MODULE
RSELECTRONIC CONTROL MODULES8E-3
BODY CONTROL MODULE (Continued)

OVERHEAD CONSOLE
TABLE OF CONTENTS
page page
OVERHEAD CONSOLE
DESCRIPTION..........................2
DIAGNOSIS AND TESTING
OVERHEAD CONSOLE..................3
STANDARD PROCEDURE
COMPASS CALIBRATION................4
COMPASS DEMAGNETIZING.............5
COMPASS VARIATION ADJUSTMENT.......5
REMOVAL.............................6
INSTALLATION..........................6
SPECIAL TOOLS
OVERHEAD CONSOLE..................7
ELECTRONIC VEHICLE INFO CENTER
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING
ELECTRONIC VEHICLE INFORMATION
CENTER.............................8
STANDARD PROCEDURE
ELECTRONIC VEHICLE INFORMATION
CENTER PROGRAMMING................8
REMOVAL.............................9
INSTALLATION.........................10
COMPASS/MINI-TRIP COMPUTER
DESCRIPTION.........................10OPERATION...........................10
DIAGNOSIS AND TESTING
COMPASS MINI-TRIP COMPUTER........10
REMOVAL.............................10
INSTALLATION.........................10
UNIVERSAL TRANSMITTER
DESCRIPTION.........................11
DIAGNOSIS AND TESTING
UNIVERSAL TRANSMITTER.............11
STANDARD PROCEDURE
SETTING TRANSMITTER CODES.........12
ERASING TRANSMITTER CODES.........12
REMOVAL.............................12
AMBIENT TEMP SENSOR
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING
AMBIENT TEMPERATURE SENSOR.......12
AMBIENT TEMPERATURE SENSOR
CIRCUIT............................12
REMOVAL.............................13
INSTALLATION.........................13
OVERHEAD CONSOLE
DESCRIPTION
Three overhead consoles options are available on
this vehicle. These options are:
²The Electronic Vehicle Information Center
(EVIC)
²The Compass Mini-Trip Computer (CMTC)
All consoles are equipped with two reading/cour-
tesy lamps and if the vehicle is equipped with a
power liftgate or power sliding door(s) the overhead
console will also include switches for these features.
The overhead console is mounted with one screw and
two snap clips to a molded plastic retainer bracket
located above the headliner.
DESCRIPTION - COMPASS
All overhead consoles include compass information.
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 be necessary
is to drive the vehicle in three complete circles at 5
to 8 kilometers-per-hour (3 to 5 miles-per-hour), on
level ground, for a minimum of forty-eight seconds.
This will reorient the compass unit to its vehicle.
8M - 2 OVERHEAD CONSOLERS

SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
electronics module is operating properly, and that all
the PCI data bus messages are being received for ini-
tial operation. Initiate the self-diagnostic test as fol-
lows:
(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 theSTEPand
theRESETbuttons. On Compass Temperature Mod-
ule (CT) equipped vehicles depress theC/Tand the
US/Mpush buttons.
(2) Turn the ignition switch to the On position.
(3) Following completion of these tests, the elec-
tronics module will display one of the following mes-
sages:
a.Pass Self Test (EVIC only), PASS (CT,
CMTC)- The electronics module is working properly.
b.Failed Self Test (EVIC only), FAIL (CT,
CMTC)- The electronics module has an internal fail-
ure. The electronics module is faulty and must be
replaced.
NOTE: If the compass functions, but accuracy is
suspect, it may be necessary to perform a variation
adjustment. This procedure allows the compass
unit to accommodate variations in the earth's mag-
netic field strength, based on geographic location.
(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
STANDARD PROCEDURE - COMPASS VARIATION
ADJUSTMENT).
NOTE: If the compass reading display is blank and
only ªCALº appears in the display, demagnetizing
may be necessary to remove excessive residual
magnetic fields from the vehicle. (Refer to 8 - ELEC-
TRICAL/OVERHEAD CONSOLE - STANDARD PRO-
CEDURE - COMPASS DEMAGNETIZING).
STANDARD PROCEDURE
COMPASS CALIBRATION
CAUTION: Do not place any external magnets, such
as magnetic roof mount antennas, in the vicinity of
the compass. Do not use magnetic tools when ser-
vicing the overhead console.The electronic compass unit features a self-cali-
brating design, which simplifies the calibration pro-
cedure. This feature automatically updates the
compass calibration while the vehicle is being driven.
This allows the compass unit to compensate for small
changes in the residual magnetism the vehicle may
acquire during normal use. If the compass readings
appear to be erratic or out of calibration, perform the
following calibration procedure. Also, new service
replacement Electronic Modules (EVIC, CMTC, CT)
must have their compass calibrated using this proce-
dure. Do not attempt to calibrate the compass near
large metal objects such as other vehicles, large
buildings, or bridges; or, near overhead or under-
ground power lines.
NOTE: Whenever the compass is calibrated manu-
ally, the variance number must also be reset. (Refer
to 8 - ELECTRICAL/OVERHEAD CONSOLE - STAN-
DARD PROCEDURE - COMPASS VARIATION
ADJUSTMENT).
Calibrate the compass manually as follows:
(1) Turn the ignition switch to the On position. If
the compass/thermometer data is not currently being
displayed, momentarily depress and release the C/T
push button to reach the compass/thermometer dis-
play.
(2) On Electronic Vehicle Information Center
(EVIC) and Compass Mini-Trip Computer (CMTC)
equipped vehicles depress the Reset push button and
hold the button until ªCALº appears in the display.
This takes about ten seconds, and appears about five
seconds after ªVAR = XXº is displayed. On Compass
Temperature Module (CT) equipped vehicles depress
the C/T push button and US/M push button down
until ªCALº appears in the display. This takes about
ten seconds, and appears about five seconds after
ªVAR = XXº is displayed.
(3) Release the push button(s).
(4) Drive the vehicle on a level surface, away from
large metal objects and power lines, through three or
more complete circles at between five and eight kilo-
meters-per-hour (three and five miles-per-hour) for a
minimum of 48 seconds. The ªCALº message will dis-
appear from the display to indicate that the compass
is now calibrated.
NOTE: If the ªCALº message remains in the display,
either there is excessive magnetism near the com-
pass, or the unit is faulty. Repeat the calibration
procedure one more time.
8M - 4 OVERHEAD CONSOLERS
OVERHEAD CONSOLE (Continued)

(1) Using the Variance Settings map, find your
geographic location and note the zone number (Fig.
3).
(2) Turn the ignition switch to the On position. If
the compass/thermometer data is not currently being
displayed, momentarily depress and release the C/T
push button to reach the compass/thermometer dis-
play.
(3) On Electronic Vehicle Information Center
(EVIC) and Compass Mini-Trip Computer (CMTC)
equipped vehicles depress the Reset push button and
hold the button down until ªVAR = XXº appears in
the display. This takes about five seconds. On Com-
pass Temperature Module (CT) equipped vehicles
depress the C/T push button and US/M push button
down until ªVAR = XXº appears in the display. This
takes about five seconds.
(4) Release the push button(s). ªVAR =XX º will
remain in the display. ªXXº equals the current vari-
ance zone setting.
(5) On Electronic Vehicle Information Center
(EVIC) and Compass Mini-Trip Computer (CMTC)
equipped vehicles momentarily depress and release
theSTEPbutton to step through the zone numbers,
until the zone number for your geographic location
appears in the display. On Compass Temperature
Module (CT) equipped vehicles depress theUS/M
push 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
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the overhead console retaining screw,
located in the front of console.
(3) 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.
Fig. 3 Variance Settings
8M - 6 OVERHEAD CONSOLERS
OVERHEAD CONSOLE (Continued)

(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 located in the overhead console. The EVIC 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 cen-
tral processing unit and interfaces with other elec-
tronic modules in the vehicle over the Programmable
Communications Interface (PCI) data bus circuit.
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 to 8 - ELECTRICAL/OVERHEAD CONSOLE/
ELECTRONIC VEHICLE INFO CENTER - STAN-
DARD PROCEDURE - ELECTRONIC VEHICLE
INFORMATION CENTER PROGRAMMING).
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 PCI data bus
circuit. The EVIC module uses its internal program-
ming and all of its data inputs to calculate and dis-
play the requested data. If the data displayed is
incorrect, perform the SELF - DIAGNOSTIC TEST
(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
DIAGNOSIS AND TESTING). If these tests prove
inconclusive, the use of a DRBIIItscan tool and the
proper diagnostic procedures information are recom-
mended for further testing of the EVIC module and
the PCI data bus circuit.
The EVIC module cannot be repaired, and is avail-
able for service only as a unit. This unit includes the
plastic module and display lens. If any of these com-
ponents is faulty or damaged, the complete EVIC
module must be replaced.
OPERATION
The Electronic Vehicle Information Center (EVIC)
uses 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 oper-
ate with the ignition switch in the On position. When
the ignition switch is turned to the On position, the
EVIC module Vacuum Fluorescent Display (VFD)
will return to the last function being displayed before
the ignition was turned to the Off position.
The compass/thermometer display is the normal
EVIC display. With the ignition switch in the On
position, momentarily depressing and releasing the
C/T (compass/thermometer) push button switch will
cause the EVIC to return to the compass/thermome-
ter/trip computer display mode from any other mode.
While in the compass/thermometer/trip computer dis-
play 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:
²Average fuel economy
²Trip odometer
²Elapsed 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 four seconds will per-
form 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 holding the Reset push
button for one second 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
DEGAUSSING TOOL #6029
RSOVERHEAD CONSOLE8M-7
OVERHEAD CONSOLE (Continued)

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 8 -
ELECTRICAL/OVERHEAD CONSOLE/ELEC-
TRONIC VEHICLE INFO CENTER - STANDARD
PROCEDURE).
DIAGNOSIS AND TESTING
ELECTRONIC VEHICLE INFORMATION CENTER
Electronic Vehicle Information Center (EVIC) data
is obtained from the Body Control Module (BCM) on
the Programmable Communications Interface (PCI)
Data Bus circuit. The EVIC 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 EVIC data is displayed,
check the PCI Data Bus circuit communications and
the BCM. If the dimming level is improper check the
PCI Data Bus circuit.
The use of a DRBIIItscan tool and the proper
diagnostic procedures information are recommended
for further testing of the EVIC module and the PCI
data bus circuit. Perform the SELF-DIAGNOSTIC
TEST before replacing the EVIC module (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - DIAGNO-
SIS AND TESTING).
STANDARD PROCEDURE
ELECTRONIC VEHICLE INFORMATION CENTER
PROGRAMMING
EVIC PROGRAMMING MODE
Some vehicles are equipped with a Electronic Vehi-
cle Information Center (EVIC) equipped overhead
console. The Electronic Vehicle Information Center
(EVIC) provides the vehicle operator with a user
interface, which allows the selection of several
optional customer programmable electronic features
to suit individual preferences. The EVIC must be
placed into its programming mode in order to view or
change the programmable features. To enter the
EVIC programming mode and to view or change the
selected programmable features options, proceed as
follows:
(1) Turn the ignition switch to the On position.
(2) Depress and release the Menu push button.
The first item in the programmable features menu
list will appear in the EVIC display.(3) Momentarily depress and release the Menu
push button to step through the programmable fea-
tures list. Each programmable feature and its cur-
rently selected option will appear on the EVIC
display in the sequence shown in the Programmable
Features list that follows.
(4) Momentarily depress and release the Step push
button to step through the available options for the
programmable feature being displayed.
(5) The option that last appears in the display
with a programmable feature before exiting the pro-
gramming mode, becomes the newly selected pro-
grammable feature option.
(6) The EVIC exits the programming mode and
returns to its normal operating mode when the C/T
push button is depressed or when the end of the pro-
grammable features menu list is reached, whichever
occurs first.
PROGRAMMABLE FEATURES
NOTE: Tire pressure monitoring (TPM) system infor-
mation is not covered in this section of the service
manual. Refer to the tires/wheels section of this
manual for detailed tire pressure monitoring system
information.
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 programmable 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.
²SERVICE INTV. =- The options include from
3200 to 12000 kilometers in 800 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.
8M - 8 OVERHEAD CONSOLERS
ELECTRONIC VEHICLE INFO CENTER (Continued)

NOTE: If the EVIC module is being replaced, the tire
pressure monitoring system (if equipped) must be
retrained. (Refer to 22 - TIRES/WHEELS/TIRE PRES-
SURE MONITORING/SENSOR - STANDARD PROCE-
DURE)
INSTALLATION
(1) Position the Electronic Vehicle Information
Center (EVIC) module in the overhead console.
(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 22 - TIRES/WHEELS/TIRE PRES-
SURE MONITORING/SENSOR - STANDARD PROCE-
DURE).
NOTE: If a new EVIC module has been installed, the
compass will have to be calibrated and the variance
set. (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - STANDARD PROCEDURE - COMPASS CAL-
IBRATION).
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The Compass Mini-Trip Computer (CMTC) module
is located in the overhead console. The CMTC con-
sists of a electronic control module with a vacuum
fluorescent display (VFD) and function switches. The
CMTC consists of a electronic module that displays
compass, trip computer, and temperature features.
Actuating the STEP push button will cause the
CMTC to change mode of operation when the ignition
is ON. Example:
²Average miles per gallon (ECO)
²Distance to empty (DTE)
²Instant miles per gallon (ECO)
²Trip odometer (ODO)
²Elapsed time (ET)
²Blank
Actuating the C/T push button will cause the
CMTC to change to the Compass/Temperature dis-
play.
OPERATION
The Compass Mini-Trip Computer (CMTC) module
in the overhead console has buttons used to select
various functions. The CMTC 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 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.
DIAGNOSIS AND TESTING
COMPASS MINI-TRIP COMPUTER
Any diagnosis of the compass mini-trip com-
puter should begin with the use of the DRB IIIt
diagnostic tool. For information on the use of
the DRB IIIt, refer to the appropriate Diagnos-
tic Procedures information.
Compass Mini-Trip Computer (CMTC) data is
obtained from the Body Control Module (BCM) on
the Programmable Communications Interface (PCI)
Data Bus circuit. The CMTC 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 CMTC data is displayed,
check the PCI Data Bus circuit communications and
the BCM. If the dimming level is improper check the
PCI Data Bus circuit.
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 (CMTC) module in the overhead console.
(4) Remove CMTC module from the console assem-
bly.
INSTALLATION
(1) Position the compass mini-trip computer
(CMTC) module in the overhead console.
(2) Install the ten screws holding the CMTC mod-
ule in the overhead console.
(3) Install the overhead console (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION).
(4) Connect the battery negative cable.
8M - 10 OVERHEAD CONSOLERS
ELECTRONIC VEHICLE INFO CENTER (Continued)

NOTE: If a new CMTC module has been installed,
the compass will have to be calibrated and the vari-
ance set. (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE - STANDARD PROCEDURE - COMPASS
CALIBRATION).
UNIVERSAL TRANSMITTER
DESCRIPTION
A Universal Transmitter transceiver is available on
some vehicles. The universal transmitter transceiver
is integral to the Electronic Vehicle Information Cen-
ter (EVIC) and the Compass Mini-Trip Computer
(CMTC) modules, which are 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 three universal transmitter push but-
tons are identified with one, two or three light indi-
cators so that they can be easily identified.
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.
DIAGNOSIS AND TESTING
UNIVERSAL TRANSMITTER
If both the Universal Transmitter and the Elec-
tronic Vehicle Information Center (EVIC) are inoper-
ative, (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE/ELECTRONIC VEHICLE INFO CENTER
- DIAGNOSIS AND TESTING). If the Universal
Transmitter is inoperative, but the EVIC is operating
normally, retrain the Transmitter with a known good
transmitter (Refer to 8 - ELECTRICAL/OVERHEAD
CONSOLE/UNIVERSAL TRANSMITTER - STAN-
DARD PROCEDURE - SETTING TRANSMITTER
CODES). If the unit is still inoperative, test the uni-
versal transmitter with the Radio Frequency Detec-
tor special tool as described below (Fig. 4):
(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.
Fig. 4 RADIO FREQUENCY DETECTOR
1 - SIGNAL DETECTION LED'S
2 - POWER LED
3 - ON/OFF SWITCH
4 - 9V BATTERY
RSOVERHEAD CONSOLE8M-11
COMPASS/MINI-TRIP COMPUTER (Continued)

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.
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 the universal transmitter removal proce-
dure, (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE/COMPASS/MINI-TRIP COMPUTER -
REMOVAL.
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console through ambient temperature messages
received from the Powertrain Control Module (PCM)
over the Programmable Communications Interface
(PCI) data bus circuit. The PCM 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 additional information on the PCM, (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent by the Powertrain Control Module (PCM). The
resistance in the sensor changes as temperature
changes, changing the temperature sensor signal cir-
cuit voltage to the PCM. Based upon the resistance
in the sensor, the PCM senses a specific voltage on
the temperature sensor signal circuit, which it is pro-
grammed to correspond to a specific temperature.
The PCM then sends the proper ambient tempera-
ture messages to the Electronic Vehicle Information
Center (EVIC)/Compass Mini-Trip Computer (CMTC)
over the Programmable Communication Interface
(PCI) data bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
PCM, the PCI data bus, and the Electronics module.
If any portion of the ambient temperature sensor cir-
cuit fails, the PCM will self-diagnose the circuit.
The ambient temperature sensor circuit can also be
diagnosed manually (Refer to 8 - ELECTRICAL/
OVERHEAD CONSOLE/AMBIENT TEMP SENSOR
- DIAGNOSIS AND TESTING - AMBIENT TEM-
PERATURE SENSOR CIRCUIT). If the temperature
sensor and circuit are confirmed to be OK, but the
temperature display is inoperative or incorrect,
(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
DIAGNOSIS AND TESTING) to determine the cause.
For complete circuit diagrams, refer to the appropri-
ate wiring information.
DIAGNOSIS AND TESTING
AMBIENT TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At room temperature (approx. 68ÉF),
the sensor resistance should be between 10-13 Kilo-
hms. The sensor resistance should be between these
two values at 68ÉF. If the resistance is out of range
replace the ambient temperature sensor.
AMBIENT TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Powertrain Control Module
(PCM) wire harness connector.
8M - 12 OVERHEAD CONSOLERS
UNIVERSAL TRANSMITTER (Continued)

²a rotary adjustment knob for temperature.
²a rotary adjustment for fan speed control.
AUTOMATIC TEMPERATURE CONTROL
Two different automatic temperature control (ATC)
heating-A/C systems are available for this model
depending on the market.
The Dual-Zone ATC system allows the driver and
front occupants to each select individual comfort tem-
peratures.
The Three-Zone ATC system allows both the driver
and front occupants and the rear intermediate occu-
pants to select individual comfort temperatures.
NOTE: Individual comfort temperatures are the per-
ceived temperature level at the individual seating
areas, NOT the actual passenger compartment air
temperature.
The ATC system includes a particulate air filter.
The filter element is the same size as the A/C evap-
orator to ensure ample capacity. A door at the base of
the HVAC housing below the glove box provides easy
access to the filter element.
The ATC computer utilizes integrated circuitry and
information carried on the programmable communi-
cations interface (PCI) data bus network to monitor
many sensors and switch inputs throughout the vehi-
cle. In response to those inputs, the internal circuitry
and programming of the ATC computer allow it to
control electronic functions and features of the ATC
system. The inputs to the ATC computer are:
²Vehicle Speed/Engine RPM± The ATC com-
puter monitors engine rpm, vehicle speed and mani-
fold absolute pressure information from the
powertrain control module (PCM).
²Coolant Temperature± ATC computer moni-
tors coolant temperature received from the PCM and
converts it to degrees Fahrenheit.
²Ambient Temperature± ATC computer moni-
tors ambient temperature from the compass mini trip
computer (CMTC) and converts it to degrees Fahren-
heit.
²Engine Miscellaneous Sensor Status±ATC
computer monitors A/C disable information from the
PCM.
²Refrigerant Pressure± ATC computer moni-
tors barometric pressure, intake air temperature,
high side pressure and methanol content as broad-
cast by the PCM.
²Door Ajar Status± The ATC computer moni-
tors driver front door, passenger front door, left rear
door, right rear door and liftgate ajar information, as
identified by the body control module (BCM), to
determine if all in-car temperatures should be main-
tained.²Dimming± The ATC computer monitors dim-
ming status from the BCM to determine the required
level of brightness and will dim accordingly.
²Vehicle Odometer± The ATC computer moni-
tors the vehicle odometer information from the BCM
to prevent flashing the vacuum-flourescent (VF) dig-
ital display icons if the manual motor calibration or
manual cool down tests have failed. Flashing of the
display icons will cease when the vehicle odometer is
greater than 3 miles.
²English/Metric± The ATC computer monitors
the English/Metric information broadcast by the
CMTC. The set temp displays for both the front and
rear control heads will be set accordingly.
²Vehicle Identification Number± The ATC
computer monitors the last eight characters of the
VIN broadcast by the PCM and compares it to the
information stored in EEPROM. If it is different, the
new number will be stored over the old one and a
motor calibration shall be initiated.
²A/C System Information± The ATC computer
will send a message for evaporator temperature too
low, fan blower relay status, evaporator sensor fail-
ure, rear window defogger relay and A/C select.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer
is mounted in the instrument panel and contains:
²a power button which allows the system to be
completely turned off. The display is blank when the
system is off.
²a rocker switch that selects a cool-down rate.
LO-AUTO or HI-AUTO are displayed when the sys-
tem is in automatic operation.
²three rocker switches that select comfort temper-
atures from 15É to 30É C (59É to 85É F), which are
shown in the VF digital display. If the set temp is 15É
C (59É F) and the down button is pressed, the set
temp value will become 13É C (55É F) but the display
will show LO. If the set temp is 29É C (85É F) and the
up button is pressed, the set temp value will become
32É C (90É F) but the display will show HIGH. Tem-
peratures can be displayed in either metric or Fahr-
enheit, which is controlled from the overhead console.
²an air conditioning button that allows the com-
pressor to be turned off. A Snowflake symbol is illu-
minated when air conditioning is on, whether under
manual or automatic control.
²an air recirculation button. A Recirculation sym-
bol appears in the display when the button is
pressed, or when the system exceeds 80 percent recir-
culated air under automatic control due to high air
conditioning demand.
²a rear window defogger on/off switch. A graphic
symbol shows when the defroster is on.
RSHEATING & AIR CONDITIONING24-3
HEATING & AIR CONDITIONING (Continued)