
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)

A eight-way power seat is standard on highline
models and optional on others. This option includes a
six-way adjustable seat cushion track and a two-way
power seat back.
The eight-way power seat is also available with the
heated seat and memory seat system that automati-
cally positions the power seat for two different driv-
ers. Refer toHeated Seat Systemfor more
information on the heated seat option. Refer toMem-
ory Systemin the Memory System section of this
group for more information on the memory system.
The power seat system includes the following com-
ponents:
²Power seat recliner
²Power seat switch
²Power seat track.
The power seat system with memory and heated
seat options includes the following components:
²Power seat recliner
²Power seat switch
²Power seat track.
²Memory Heated Seat Module (MHSM)
²Memory set switch
²Heated seat switch
²Electronic Vehicle Information Center (EVIC)
²Programmable Communications Interface (PCI)
data bus network
Refer to Wiring Diagrams for complete circuit dia-
grams. Following are general descriptions and opera-
tions for the major components in the power seat
system and memory seat system.
DESCRIPTION - MEMORY SEAT SYSTEM
An electronic memory and heated seat system is
available on some models. The memory system is
able to store and recall the driver side power seat
positions (including the power recliner position), and
both outside power mirror positions for two drivers.
For vehicles with a radio and heated / memory seat
system connected to the Programmable Communica-
tions Interface (PCI) data bus network, the memory
system is also able to store and recall radio station
presets for two drivers. The memory system also will
store and recall the last station listened to for each
driver, even if it is not one of the preset stations.
The memory system will automatically return to
all of these settings when the corresponding num-
bered and button of the memory switch on the driver
side seat side shield is depressed, or when the doors
are unlocked using the Remote Keyless Entry (RKE)
transmitter. A customer programmable feature of the
memory system allows the RKE recall of memory fea-
tures to be disabled in cases where there are more
than two drivers of the vehicle.
A Memory Heated Seat Module (MHSM) is used on
some models to control and integrate the many elec-tronic functions and features included in the memory
/ heated seat system.
The memory system includes the following compo-
nents:
²Heated seat switch
²Memory heated seat module (MHSM)
²Memory switch
²Position potentiometers on both outside power
mirrors
²Position potentiometers on the driver side power
seat track and power seat recliner motors.
²Radio receiver (if PCI data bus capable).
Certain functions and features of the memory system
rely upon resources shared with other electronic mod-
ules in the vehicle over the Programmable Communica-
tions Interface (PCI) J1850 data bus network. The PCI
data bus network allows the sharing of sensor informa-
tion. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor cur-
rent loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and allows
the addition of many new feature capabilities. For diag-
nosis of these electronic modules or of the PCI data bus
network, the use of a DRBtscan tool and the proper
Diagnostic Procedures manual are recommended.
The other electronic modules that may affect mem-
ory system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
²
Electronic Vehicle Information Center (EVIC)
- Refer toElectronic Vehicle Information Center
in Overhead Console Systems for more information.
²Powertrain Control Module (PCM)- Refer to
Powertrain Control Modulein Electronic Control
Modules for more information.
²Radio Receiver- Refer toRadio Receiverin
Audio Systems for more information.
Refer toHeated Seat Systemfor more informa-
tion on the heated seat system. Refer toRemote
Keyless Entry Systemin Power Lock Systems for
more information on the RKE system. Refer to
Power Mirrorin Power Mirrors for more informa-
tion on the mirror position potentiometers. Refer to
Power Seat TrackandPower Seat Reclinerin
the Power Seat System section of this group for more
information on the driver side power seat position
potentiometers.
Refer toPower Seatin the Contents of Wiring
Diagrams for complete circuit diagrams. Following
are general descriptions of the remaining major com-
ponents in the factory-installed memory system.
OPERATION - POWER SEAT SYSTEM
The power seat system allows the driver and/or
front passenger seating positions to be adjusted elec-
8N - 50 POWER SEATSRS
POWER SEATS (Continued)