able on the CS model. The base overhead console
includes a universal transmitter and push buttons.
Option two includes the universal transmitter and
power liftgate push buttons (Fig. 1). Option three
includes the universal transmitter and power sunroof
push buttons. The final option includes all of the fea-
tures mentioned, universal transmitter, power lift-
gate and power sunroof push buttons. All overhead
consoles are equipped with a internal Compass Mini-
Trip Computer (CMTC) module, two reading/courtesy
lamps and a storage bin. The overhead console is
mounted with one screw and two snap clips to a
molded plastic retainer bracket located above the
headliner.

The overhead console CMTC module display and

Electronic Vehicle Information Center (EVIC) is built
in to the instrument cluster on this model. The
instrument panel switch pod contains the US/M,
MENU, STEP and RESET push buttons used to con-
trol the CMTC and EVIC displays. Refer to Instru-

ment Cluster and Instrument Panel Switch Pod for
more information.

DESCRIPTION - COMPASS

When in the compass/temperature mode, the clus-

ter will display the direction in which the vehicle is
pointed using the eight major compass headings
(Examples: north is N, northeast is NE). The CMTC
module contains a self-calibrating compass that
requires no adjusting in normal use. The only cali-
bration that may prove necessary is to drive the vehi-
cle in three complete circles at 5 to 8 kilometers-per-
hour (3 to 5 miles-per-hour), on level ground, in not
less than forty-eight seconds. This will reorient the
compass to its vehicle.

The compass will compensate for magnetism the

body of the vehicle may acquire during normal use.
However, avoid placing anything magnetic directly on
the roof of the vehicle. Magnetic mounts for an
antenna, a repair order hat, or a funeral procession
flag can exceed the compensating ability of the com-
pass unit if placed on the roof panel. Magnetic bit
drivers used on the fasteners that hold the overhead
console assembly to the roof header can also affect
compass operation. If the vehicle roof should become
magnetized, the demagnetizing and calibration proce-

MESSAGE SYSTEMS

8M - 1

dures found in this section may be required to
restore proper compass operation.

Following are general descriptions of the major

components used in the overhead console. Refer to
Instrument Cluster for more information.

DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE

The most reliable, efficient, and accurate means to

diagnose the overhead console or related system
requires the use of a DRB III

t scan tool and the Ser-

vice and Body Diagnostic Procedures Manuals. The
DRB III

t scan tool can provide vital information to

the technician trying to find a problem with a over-
head console component. Diagnostic logic is built into
the overhead console mounted module to help the
person trying to locate the problem by the most effi-
cient means possible. Anytime a problem is sus-
pected, a DRB III

t scan tool must be obtained and

used to retrieve any stored fault codes in the module.
If diagnostic fault codes are present in the module,
record them on a piece of paper immediately before
proceeding any further. Then, use these fault codes to
identify the problem by verifying the fault code.
Example, If the module records “TIRE PRESSURE
N/A” fault, locate the diagnostic procedure for this
code in the appropriate Body Diagnostic Procedures
Manual and follow the flow chart until the specific
problem is located and resolved. Once the problem is
thought to be corrected, erase the stored fault code

using the DRB III

t scan tool and verify correct sys-

tem operation. If the tire pressure monitoring system
is functioning correctly, verify that there are no other
stored codes in the module and return the vehicle to
service.

If the fault code could not be verified, such as not

finding anything wrong when following the diagnos-
tic flow chart in the Body Diagnostic Procedures
Manual. This is a good indication that a INTERMIT-
TENT problem may be present. You must than
attempt to find the intermittent problem, such as
running a tire pressure monitoring system self test.
Refer to the Tires/Wheels section for more informa-
tion. Always, eliminate all other potential problems
before attempting to replace the module.

TESTING VOLTAGE AND GROUND SUPPLY TO
OVERHEAD CONSOLE

(1) Remove the overhead console from the head-

liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL) Disconnect the overhead console
electrical connector. Check the fused B(+) circuit in
the overhead console electrical connector. If OK, go to
Step 2. If not OK, repair the open circuit or compo-
nent as required. Refer to the Wiring section for
detailed schematics.

(2) Check the IGN RUN B(+) circuit in the over-

head console electrical connector. If OK, go to Step 3.
If not OK, repair the open IGN RUN B(+) circuit as
required.

(3) Check the Ground circuit in the overhead con-

sole electrical connector. If OK, go to Step 4. If not
OK, repair the open ground circuit as required.

(4) If the tire pressure monitoring system is not

operating properly, replace the module with a known
good unit and retest the system. Refer to the Tires/
Wheels section for more information on the tire pres-
sure monitoring system.

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 Compass Variation Adjustment in the Stan-
dard Procedures section of this group.

NOTE: If the compass reading displays dashes, and
only “CAL” appears in the display, demagnetizing
may be necessary to remove excessive residual
magnetic fields from the vehicle. Refer to Compass
Demagnetizing in the Standard Procedures section
of this group.

Fig. 1 CS Overhead Console

1 - Storage Bin Door
2 - Reading/Courtesy Lamps

8M - 2

MESSAGE SYSTEMS

OVERHEAD CONSOLE (Continued)

STANDARD PROCEDURE

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 that the vehicle
may acquire during normal use. If the compass read-
ings appear to be erratic or out of calibration, per-
form the following calibration procedure. Also, new
CMTC Modules must have their compass calibrated
using this procedure. Do not attempt to calibrate the
compass near large metal objects such as other vehi-
cles, large buildings, or bridges; or, near overhead or
underground power lines.

NOTE: Whenever the compass is calibrated manu-
ally, the variance number must also be reset. Refer
to Compass Variation Adjustment in this group.

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
STEP push button to reach the compass/thermometer
display.

(2) Depress the Reset push button and hold the

button down until “CAL” appears in the cluster dis-
play. This takes about ten seconds, and appears
about five seconds after “VAR = XX” 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) in
not less than 48 seconds. The “CAL” message will
disappear from the display to indicate that the com-
pass is now calibrated.

NOTE: If the “CAL” 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.

NOTE: If the wrong direction is still indicated in the
compass display, the area selected for calibration

may be too close to a strong magnetic field. Repeat
the calibration procedure in another location.

STANDARD PROCEDURE - COMPASS
DEMAGNETIZING

A degaussing tool (Special Tool 6029) is used to

demagnetize, or degauss, the overhead console for-
ward mounting screw and the roof panel above the
overhead console. Equivalent units must be rated as
continuous duty for 110/115 volts and 60 Hz. They
must also have a field strength of over 350 gauss at 7
millimeters (0.25 inch) beyond the tip of the probe.

To demagnetize the roof panel and the overhead

console forward mounting screw, proceed as follows:

(1) Be certain that the ignition switch is in the Off

position, before you begin the demagnetizing proce-
dure.

(2) Connect the degaussing tool (Fig. 2) to an elec-

trical outlet, while keeping the tool at least 61 centi-
meters (2 feet) away from the compass unit.

(3) Slowly approach the head of the overhead con-

sole forward mounting screw with the degaussing
tool connected.

(4) Contact the head of the screw with the plastic

coated tip of the degaussing tool for about two sec-
onds.

(5) With the degaussing tool still energized, slowly

back it away from the screw. When the tip of the tool
is at least 61 centimeters (2 feet) from the screw
head, disconnect the tool.

(6) Place a piece of paper approximately 22 by 28

centimeters (8.5 by 11 inches), oriented on the vehicle
lengthwise from front to rear, on the center line of
the roof at the windshield header (Fig. 3). The pur-
pose of the paper is to protect the roof panel from
scratches, and to define the area to be demagnetized.

(7) Connect the degaussing tool to an electrical

outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.

(8) Slowly approach the center line of the roof

panel at the windshield header, with the degaussing
tool connected.

(9) Contact the roof panel with the plastic coated

tip of the degaussing tool. Be sure that the template
is in place to avoid scratching the roof panel. Using a
slow, back-and-forth sweeping motion, and allowing
13 millimeters (0.50 inch) between passes, move the

Fig. 2 Degaussing Tool 6029

MESSAGE SYSTEMS

8M - 3

OVERHEAD CONSOLE (Continued)

tool at least 11 centimeters (4 inches) to each side of
the roof center line, and 28 centimeters (11 inches)
back from the windshield header.

(10) With the degaussing tool still energized,

slowly back it away from the roof panel. When the
tip of the tool is at least 61 centimeters (2 feet) from
the roof panel, disconnect the tool.

(11) Calibrate the compass and adjust the compass

variance. Refer to procedure in this section for
detailed instructions.

STANDARD PROCEDURE - COMPASS
VARIATION ADJUSTMENT

Compass variance, also known as magnetic decli-

nation, is the difference in angle between magnetic
north and true geographic north. In some geographic
locations, the difference between magnetic and geo-
graphic north is great enough to cause the compass
to give false readings. If this problem occurs, the
compass variance setting may need to be changed.

To set the compass variance:
(1) Using the Variance Settings map, find your

geographic location and note the zone number (Fig.
4).

(2) Turn the ignition switch to the On position. If

the compass/thermometer data is not currently being

displayed, momentarily depress and release the
STEP push button to reach the compass/thermometer
display.

(3) Depress the Reset push button and hold the

button down until “VAR = XX” appears in the display.
This takes about five seconds.

(4) Release the push button(s). “VAR =XX ” will

remain in the display. “XX” equals the current vari-
ance zone setting.

(5) Momentarily depress and release the STEP

push button to step through the zone numbers, until
the

zone

number

for

your

geographic

location

appears in the display.

(6) Momentarily depress and release the RESET

push button to enter the displayed zone number into
the module memory.

(7) Confirm that the correct directions are now

indicated by the compass.

REMOVAL - OVERHEAD CONSOLE

(1) Disconnect and isolate the negative battery

cable.

(2) Open the storage bin and remove the T10 over-

head console retaining screw.

(3) Using your fingertips, grasp the sides of the

overhead console and pull down and rearward evenly
to disengage the unit.

(4) Lower the overhead console far enough to

access the wire harness connectors.

(5) Disconnect the electronic module and the read-

ing/courtesy lamps electrical connector.

(6) Remove the overhead console from the vehicle.

DISASSEMBLY

(1) Remove the overhead console from the vehicle

(Refer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
REMOVAL).

(2) Remove the two module retaining screws (Fig.

5).

(3) Disconnect the module electrical connector.

Depress the connector retaining tab and pull straight
apart.

(4) Remove the module from the overhead console.

ASSEMBLY

(1) Connect the module electrical connector.
(2) Position the module and install the two module

retaining screws.

(3) Install the overhead console in the vehicle.

INSTALLATION

(1) Position the overhead console in the vehicle.
(2) Connect the electronic module and the reading/

courtesy lamps electrical connector.

Fig. 3 Roof Demagnetizing Pattern

8M - 4

MESSAGE SYSTEMS

OVERHEAD CONSOLE (Continued)

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