this type of system would only refer to this circuit.
A faulty speaker could not cause this DTC.
3.2.1 REMOTE RADIO CONTROLS
These radios can be controlled via remote radio
switches (optional). These switches are located on
the back side of the steering wheel. They control
mode, preset, seek up, seek down, volume up and
volume down functions.
These functions are inputs to the Body Control
Module and can be read with the DRBIIItunder
ªbody computerº. The switches are a multiplexed
signal to the BCM. The radio control MUX circuit is
a 5 volt line that is pulled to ground through
different value resistors built into the switches.
This causes a voltage drop to be seen by the BCM
and it sends a specific message to the radio on the
PCI Bus circuit. The radio then responses to the
message.
This circuit is fairly simple to troubleshoot. The
circuit must be complete from the switches in the
steering wheel to the BCM. The ground must be
complete so that the switches can cause the voltage
drop for the BCM to see. The circuit passes through
the clockspring so continuity through this devise
must be verified.
3.2.2 CD CHANGER
The new in-dash CD Changer is designed to fit
into the existing cubby bin in the center stack. This
new cartridge-less CD Changer is controlled by
your radio, and allows you to individually load up to
four discs at a time. However, due to its compact
design, the CD Changer can only carry out one
operation at a time. For example, you can not load
a new disc while playing another at the same time.
Each operation happens sequentially.
The radio unit installed with your system pro-
vides control over all features of the CD Changer
with the exception of the CD load and eject func-
tions, which are controlled by buttons located on the
front of the CD Changer. The radio also supplies the
power, ground, PCI Bus, left and right speaker
output thru a single DIN cable. All features you
would expect, such as Disc Up/Down, Track Up/
Down, Random and Scan are controlled by the
radio, which also displays all relevant CD Changer
information on the radio display.
The CD Changer contains a Load/Eject button
and an indicator light for each of the four disc
positions. The individual light indicates whether a
CD is currently loaded in that particular chamber of
the CD Changer. Pressing the individual Load/Eject
button for a particular chamber will eject a disc
currently present in that chamber. If the chamber iscurrently empty, actuating the Load/Eject button
will position that chamber to receive and load a new
disc in that chamber.
3.3 BODY CONTROL MODULE
The body control module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the module is interfaced to the
vehicle's serial bus communications network (PCI).
This network consists of the powertrain control
module (PCM), the engine control module (ECM) -
diesel only, the transmission control module (TCM),
the mechanical instrument cluster (MIC), the front
control module (FCM), the occupant restraint con-
troller (ORC), the compass/mini-trip (CMTC), the
electronic vehicle information center (EVIC), the
controller antilock brake (CAB), the HVAC control
module (ATC & MTC), the power sliding door (Left
& Right) modules (PSD), the power liftgate module
(PLG), the Audio system, the side impact airbag
control (left & right) modules (SIACM), the memory
seat/mirror module (MSMM), the RKE/thatcham
alarm module and the sentry key immobilizer mod-
ule (SKIM). The BCM is operational when battery
power is supplied to the module.
The body control module provides the following
features:
²Power Door Locks
²Automatic Door Lock
²Door Lock Inhibit
²Central Locking (with VTSS Only)
²Battery Protection
²The 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
²Compass/Minitrip Support
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Power Folding Mirrors
²Remote Radio Controls
²Headlamp Time Delay (with/without Autohead-
lamps)
²Automatic Headlamps (with electrochromatic
mirror)
²Illuminated Entry
²Fade to Off
8
GENERAL INFORMATION
NOTE: A POWERTRAIN CONTROL MODULE
FROM A VEHICLE EQUIPPED WITH A
VEHICLE THEFT SECURITY SYSTEM
CANNOT BE USED IN A VEHICLE THAT IS
NOT EQUIPPED WITH A VEHICLE THEFT
SECURITY SYSTEM IF THE VTSS INDICATOR
LAMP COMES ON AFTER IGNITION ON AND
STAYS ON, THE PCI BUS COMMUNICATION
WITH THE POWERTRAIN CONTROL
MODULE HAS POSSIBLY BEEN LOST.
3.20.2 THATCHAM ALARM SYSTEM
The Thatcham Alarm Module monitors the vehi-
cle doors, liftgate, hood and the interior of the
vehicle for unauthorized operation. The vehicle
doors, liftgate, and hood use ajar switches as inputs
to the BCM to indicate their current status. The
interior of the vehicle is secured by the use of
Intrusion Sensors. The Intrusion Sensors are used
as inputs to the RKE/Thatcham Alarm Module to
report any motion in the interior of the vehicle. The
alarm activates by sounding the siren, flashing the
hazard lamps, and the VTSS Indicator Lamp.
Arming
Before arming, all doors, liftgate, and the hood
must be completely closed. The system can then be
armed by following a normal exit sequence, of
opening the door and then locking the doors with
the door lock switch and then closing the door. The
system can also be armed by opening the door,
closing the door and then locking the doors with the
RKE transmitter.
Disarming
To disarm the alarm system, the RKE transmit-
ter is used. The RKE transmitter will unlock the
vehicle doors and disarm the alarm system. The
RKE transmitter can also be used to halt the alarm
once it has been activated.
3.21 WIPER SYSTEM
3.21.1 FRONT WIPER
The front wiper/washer system consists of the
following features: lo-hi-speed, mist wipers, inter-
mittent wipers and wipe after wash. The front
wiper system is only active when the ignition switch
is in the RUN/ACC position. The vehicle operator
selects the front wiper function using the front
wiper switch (a resistive multiplexed stalk switch)
which is integral to the Multi-Function Switch. The
front wiper switch is hardwired to the Body Control
Module (BCM). Upon receiving a wiper switch sig-
nal, the BCM sends a PCI Bus message to the Front
Control Module (FCM). The FCM controls the ON/OFF relay, the HIGH/LOW relay and the front and
rear washer pump motors.
The Wiper system utilizes the BCM to control the
on/off and hi/low relays for the low and hi speed
wiper functions, intermittent wiper delay as the
switch position changes, pulse wipe, wipe after
wash mode and wiper motor functions. The BCM
uses the vehicle speed input to double the usual
delay time below 10 MPH (6 KPH).
3.21.2 SPEED SENSITIVE INTERMITTENT
WIPE MODE
There are 5 individual delay time settings with a
minimum delay of 1.7 seconds to a maximum of 18.4
seconds. When the vehicle speed is under 10 MPH
(6 KPM), the delay time is doubled, providing a
delay range of 3.4 seconds to 36.8 seconds.
3.21.3 PULSE WIPE
When the wiper is in the off position and the
driver presses the wash button for more than .062
seconds, but less than .5 seconds, 2 wipe cycles in
low speed mode will be provided.
3.21.4 PARK AFTER IGNITION OFF
Because the wiper relays are powered from the
battery, the BCM can run the wipers to park after
the ignition is turned off.
3.21.5 WIPE AFTER WASH
When the driver presses the wash button for over
.5 seconds and releases it, the wiper will continue to
run for 2 additional wipe cycles.
3.21.6 REAR WIPER
The rear wiper/washer system consists of the
following features: mist wipers, intermittent wipers
and wipe after wash. The rear wiper system is only
active when the ignition switch is in the RUN/ACC
position. The vehicle operator selects the rear wiper
function using one of the three buttons on the dash
mounted rear wiper switch. The rear wiper switch
is hardwired to the Body Control Module (BCM).
Upon receiving a wiper switch signal, the BCM
provides 12 volts to the rear wiper motor. Rear
washer occurs when the BCM receives a rear
washer switch ON input. The BCM sends a PCI Bus
message to the FCM requesting rear washer on.
The FCM activates the rear washer by providing a
ground for the rear washer motor.
3.21.7 SPEED SENSITIVE INTERMITTENT
WIPE MODE
The delay setting of the rear wiper system is
based solely on the vehicle speed. The delay time is
27
GENERAL INFORMATION
CD CHANGER
DESCRIPTION
The 4 Disc In-Dash CD Changer (if equipped) is
located in the instrument panel below the radio. The
remote changer does not use a cartridge or magazine
for the CD's. Up to 4 CD's can be directly loaded into
this unit.
OPERATION
Due to its compact design, the CD changer can
carry out only one operation at a time. For example,
you can not load a new disc while playing another at
the same time. Each operation happens sequentially.
The radio unit provides control over all features of
the CD changer with the exception of the CD load
and eject functions, which are controlled by buttons
located on the front of the CD changer. All features
you would expect, such as Disc Up/Down, Track
Up/Down, Random and Scan are controlled by the
radio, which also displays all relevant CD changer
information on the radio display.
The CD changer contains a Load/Eject button and
an indicator LED for each of the four disc positions
as well as an illuminated disc opening. The individ-
ual LED indicates whether a CD is currently loaded
in that particular chamber of the CD changer. Press-
ing the individual Load/Eject button for a particular
chamber will eject a disc currently present in that
chamber. If the chamber is currently empty, actuat-
ing the Load/Eject button will position that chamber
to receive and load a new disc in that chamber.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove screws holding CD changer.
(3) Disconnect the wire connector from the back of
the CD changer.
(4) Remove the CD changer from the vehicle (Fig.
5).
INSTALLATION
(1) Reconnect the wire connector to the CD
changer.
(2) Insert the CD changer into the instrument
panel.
NOTE: Use care when inserting CD changer so that
cable is not pinched or trapped against instrument
panel.
(3) Install screws holding CD changer.
(4) Reconnect the battery negative cable.
CHOKE
DIAGNOSIS AND TESTING
If the audio system is cutting in and out at higher
volumes, check for continuity across the choke con-
nector. If no continuity, replace the choke assembly.
The choke is located on the junction block/body con-
trol module.
D-PILLAR SPEAKER
REMOVAL
PASSENGER SIDE
(1) Disconnect and isolate the battery negative
cable.
(2) Remove rear header trim.
(3) Remove liftgate scuff plate.
(4) Remove upper seat belt bolt. (Refer to 8 -
ELECTRICAL/RESTRAINTS/SEAT BELT OUT-
BOARD FRONT - REMOVAL).
(5) Partially remove quarter trim panel to access
the D-pillar speaker.
(6) Slide the speaker from the retainer (Fig. 6).
(7) Disconnect the wire harness connector from the
speaker.
DRIVER SIDE
(1) Disconnect and isolate the negative battery
cable.
(2) Remove jack cover.
(3) Remove liftgate scuff plate.
(4) Partially remove quarter trim panel to access
the D-pillar speaker.
Fig. 5 CD - PLAYER
1 - CD-PLAYER
2 - POWER OUTLET
8A - 6 AUDIORS
(4) Connect battery negative cable.
QUARTER PANEL SPEAKER
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove speaker grill by prying away from trim
panel.
(3) Remove speaker retaining screws (Fig. 9).
(4) Disconnect wire harness connector from
speaker.
INSTALLATION
(1) Connect the wire harness to the speaker.
(2) Install the speaker retaining screws.
(3) Install speaker grill by pressing into the trim
panel.
(4) Connect the battery negative cable.
RADIO
DIAGNOSIS AND TESTING
If the vehicle is equipped with remote radio
switches located on the backs of the steering wheel
spokes, and the problem being diagnosed is related to
one of the symptoms listed below, be certain to check
the remote radio switches and circuits as described
in this group, prior to attempting radio diagnosis or
repair.
²Stations changing with no remote radio switch
input
²Radio memory presets not working properly
²Volume changes with no remote radio switch
input
²Remote radio switch buttons taking on other
functions
²CD player skipping tracks
²Remote radio switch inoperative.
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector 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.
WARNING:
ON VEHICLES EQUIPPED WITH AIRBAGS, REFER
TO ELECTRICAL, RESTRAINTS BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. FAILURE TO TAKE THE PROPER
PRECAUTIONS COULD RESULT IN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
CAUTION:
The speaker output of the radio is a ªfloating
groundº system. Do not allow any speaker lead to
short to ground, as damage to the radio may result.
(1) Check the fuse(s) in the junction block and the
Intelligent Power Module. If OK, go to Step 2. If not
OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).
(2) Check for battery voltage at the fuse in the
Intelligent Power Module. If OK, go to Step 3. If not
Fig. 8 DOOR SPEAKER
1 - DOOR SPEAKER
2 - HARNESS CONNECTOR
Fig. 9 QUARTER PANEL SPEAKER
1 - SPEAKER
2 - TRIM PANEL
8A - 8 AUDIORS
DOOR MOUNTED SPEAKER (Continued)
driving out of a heated garage into winter tempera-
tures.
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 thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle, and is hard wired to the
Front Control Module (FCM). The FCM sends tem-
perature 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 & TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSelf-Diag-
nostic Testlater in this group. 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 Control Module (FCM) over the J1850 Pro-
grammable Communications Interface (PCI) data bus
circuit. If the problem is a no-display condition, use
the following procedures. For complete circuit dia-
grams, refer toOverhead Consolein the Wiring
Diagrams section of the service manual.
(1) Check the fused B(+) fuse in the intelligent
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 intelligent power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the intelligent power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the intelligent 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 switchoutput (run/start) fuse in the intelligent 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 intel-
ligent 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 Testlater 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 intelligent 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.
(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:
²Pass Self Test (EVIC only), PASS (CT,
CMTC)- The electronics module is working properly.
²Failed Self Test (EVIC only), FAIL (CT,
CMTC)- The electronics module has an internal fail-
ure. The electronics module is faulty and must be
replaced.
²Failed J1850 Communication (EVIC only),
BUS (CT, CMTC)- The electronics module is not
receiving proper message input through the J1850
PCI data bus circuit. This can result from one or
RSOVERHEAD CONSOLE8M-3
OVERHEAD CONSOLE (Continued)
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 Service
Procedures section of this group for more information
on the customer programmable feature options.
If the vehicle is equipped with the optional
Homelinkttransceiver, the EVIC will also display
messages and an icon indicating when the
Homelinkttransceiver is being trained, which of the
three transmitter buttons is transmitting, 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-
sive, the use of a DRBIIItscan tool and the proper
Diagnostic Procedures manual are recommended for
further testing of the EVIC module and the J1850
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 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/thermometer display is the normal
EVIC display. With the ignition switch in the Onposition, 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: 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 & TESTING - ELECTRONIC
VEHICLE INFORMATION CENTER
Electronic Vehicle Information Center (EVIC) data
is obtained from the Body Control Module (BCM) on
the J1850 Data Bus circuit. The EVIC will display
dashes (- -) for any of the screens it did not receive
the bus messages. The label corresponding to the
missing information will be lit. If no EVIC data is
displayed, check the J1850 Data Bus circuit commu-
nications 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
EVIC self diagnosis before replacing the EVIC mod-
ule.
RSOVERHEAD CONSOLE8M-7
ELECTRONIC VEHICLE INFO CENTER (Continued)
recall memory settings when the Driver 1 or Driver 2
push buttons of the memory switch on the driver side
front door trim panel are depressed.
²SOUND HORN ON LOCK?- The options
include Yes and No. The default is No. When Yes is
selected, a short horn chirp will provide an audible
confirmation when the RKE receiver recognizes a
valid Lock signal from an RKE transmitter. When No
is selected, no horn chirp will occur with the RKE
Lock event. This feature may be selected indepen-
dent of theFLASH LIGHTS WITH LOCKS?pro-
grammable feature.
²FLASH LIGHTS WITH LOCKS?- The options
include Yes and No. The default is Yes. When Yes is
selected, a single flash of the hazard warning lamps
will provide an optical confirmation when the RKE
receiver recognizes a valid Lock signal from an RKE
transmitter, and two flashes of the same lamps will
occur when the RKE receiver recognizes a valid
Unlock signal from an RKE transmitter. When No is
selected, no lamp flash will occur with the RKE Lock
or Unlock event. This feature may be selected inde-
pendent of theSOUND HORN ON LOCK?pro-
grammable feature.
²HEADLAMP DELAY =- The options include
Off, 30 Sec, 60 Sec, and 90 Sec. The default is 90 Sec.
When a time interval is selected, the headlamps will
remain on for that length of time when the head-
lamps are turned off after the ignition is turned off,
or if the Auto mode is selected on vehicles with the
Auto Headlamps option. When Off is selected, the
headlamp delay feature is disabled.
²HEADLAMPS ON WITH WIPERS?- This pro-
grammable feature only applies to vehicles equipped
with the optional Auto Headlamps. The options
include Yes and No. The default is No. When Yes is
selected, the headlamps will turn on automatically
when the windshield wipers are turned on. The head-
lamps will turn off when the wipers are turned off,
as long as the headlamp switch is in the Auto or Off
positions. When No is selected, the headlamps will
only turn on if manually selected or if the Auto mode
is selected and the outside ambient light levels dic-
tate that they should be on.
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.
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 Overhead
Console Removal and Installation in this section.
(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 the Service Procedures sec-
tion of this group for the 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.
RSOVERHEAD CONSOLE8M-9
ELECTRONIC VEHICLE INFO CENTER (Continued)
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
²
All segments of the VFD will light for one second
²Blanks momentarily
²Returns to the last mode setting selected before
the ignition was last switched OFF.
DIAGNOSIS & 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 Overhead
Console Removal and Installation in this section(Re-
fer to 8 - ELECTRICAL/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 Overhead
Console Removal and Installation in this section.
(4) Connect the battery negative cable.
NOTE: If a new module has been installed, the com-
pass will have to be calibrated and the variance set.
Refer to Compass Variation Adjustment and Com-
pass Calibration in the Service Procedures section
of this group for the procedures.
UNIVERSAL TRANSMITTER
DESCRIPTION
On some RS models a Homelinkttransceiver is
standard factory-installed equipment. The Homelinkt
transceiver is integral to the Electronic Vehicle Infor-
mation Center (EVIC) and the Compass Mini-Trip
Computer (CMTC), which is located in the overhead
console. The only visible component of the Homelinkt
are the three transmitter push buttons centered
between the modules push buttons located just rear-
ward of the display screen in the overhead console.
The three Homelinkttransmitter 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 Homelinkttransmitter 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 Homelinktis capable of operating systems
using either rolling code or non-rolling code technol-
ogy.
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 Homelinkt. The EVIC mes-
sages are:
²Cleared Channels- Indicates that all of the
transmitter codes stored in the Homelinkthave been
successfully cleared.
²Training- Indicates that the Homelinktis in
its transmitter learning mode.
²Trained- Indicates that the Homelinkthas
successfully acquired a new transmitter code.
²Transmit- Indicates that a trained Homelinkt
transmitter button has been depressed and that the
Homelinktis transmitting.
The Homelinktcannot be repaired, and is avail-
able 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 Homelinktoperates 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, programming procedures
and operation of the Homelinkt, see the owner's
manual in the vehicle glove box.
8M - 10 OVERHEAD CONSOLERS
COMPASS/MINI-TRIP COMPUTER (Continued)