The JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

TRAILER TOW RELAY
DESCRIPTION
The trailer tow relays are located in a connector
bank above the right rear wheelhouse and behind the
quarter trim panel on vehicles equipped with the
optional factory-installed trailer towing package.
Four individual relays are used, one each for fused
ignition switch output (run), brake lamps, right turn
signal, and left turn signal outputs to a trailer
through the rear body wiring and connectors. The
trailer tow relays are conventional International
Standards Organization (ISO) micro relays (Fig. 64).
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The relay is
contained within a small, rectangular, molded plastic
housing and is connected to all of the required inputs
and outputs by five integral male spade-type termi-
nals that extend from the bottom of the relay base.
The trailer tow relays cannot be adjusted or
repaired and, if faulty or damaged, the inoperative
relay must be replaced.
OPERATION
The trailer tow relays are electromechanical
switches. The relays each use an input from the cir-
cuit that they isolate from the trailer wiring to con-
trol a high current output to the trailer. The movable
common feed contact point is held against the fixed
normally closed contact point by spring pressure.When the relay coil is energized, an electromagnetic
field is produced by the coil windings. This electro-
magnetic field draws the movable relay contact point
away from the fixed normally closed contact point,
and holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The terminals of each trailer tow relay are con-
nected to the vehicle electrical system through a con-
nector bank in the rear lighting wire harness above
the right rear wheelhouse. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds. The trailer tow relays can be diagnosed
using conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - TRAILER TOW
RELAY
The trailer tow relays (Fig. 65) are located in a
connector bank above the right rear wheelhouse.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
Fig. 64 Trailer Tow Relays
1 - RELAY CONNECTOR BANK
2 - REAR BODY WIRE HARNESS
3 - LEFT TURN RELAY
4 - RIGHT TURN RELAY
5 - BRAKE LAMP RELAY
6 - FUSED IGNITION SWITCH OUTPUT (RUN) RELAY
8Ls - 62 LAMPSKJ

(1) Remove the trailer tow relay from the connec-
tor bank. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/TRAILER TOW RELAY -
REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, test the input and output circuits of
the relay. Refer to the appropriate wiring informa-
tion.
REMOVAL
The trailer tow relay bank contains four relays.
The service procedures for each relay are the same.
Be certain any removed relay is replaced with the
same relay size and type that was removed.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THENWAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim from the right side quarter
inner panel. (Refer to 23 - BODY/INTERIOR/QUAR-
TER TRIM PANEL - REMOVAL).
(3) Reach through the access hole in the quarter
inner panel behind the right rear wheelhouse to
locate and retrieve the trailer tow relay connector
bank, which is enveloped in foam rubber and placed
on the top of the right rear wheelhouse between the
quarter inner and outer panels (Fig. 66).
(4) Pull the trailer tow relay connector bank into
the cargo area far enough to access the unit for ser-
vice.
(5) Carefully remove the trailer tow relay connec-
tor bank from the foam wrap.
(6) Remove the trailer tow relay by grasping it
firmly and pulling it straight out from the connector
bank (Fig. 67).
INSTALLATION
The trailer tow relay bank contains four relays.
The service procedures for each relay are the same.
Be certain any removed relay is replaced with the
same relay size and type that was removed.
Fig. 65 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 66 Trailer Tow Relay Wrap
1 - FOAM WRAP
2 - REAR BODY WIRE HARNESS
KJLAMPS8Ls-63
TRAILER TOW RELAY (Continued)

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the trailer tow relay to the proper con-
nector in the connector bank (Fig. 67).
(2) Align the trailer tow relay terminals with the
terminal cavities in the connector.
(3) Push firmly and evenly on the top of the trailer
tow relay until the terminals are fully seated in the
terminal cavities in the connector.
(4) Carefully restore the foam wrap around the
trailer tow relay connector bank (Fig. 66).
(5) Reach through the access hole in the quarter
inner panel behind the right rear wheelhouse to
place the trailer tow relay connector bank on the top
of the right rear wheelhouse between the quarter
inner and outer panels.(6) Reinstall the trim onto the right side quarter
inner panel. (Refer to 23 - BODY/INTERIOR/QUAR-
TER TRIM PANEL - INSTALLATION).
(7) Reconnect the battery negative cable.
TRAILER TOW WIRING
DESCRIPTION
Vehicles equipped with an optional factory-in-
stalled (not dealer-installed or port-installed) trailer
towing package have a rear body wire harness that
includes an integral trailer tow wiring take out that
connects to a heavy duty, sealed, 7-pin trailer tow
connector located on a bracket on the trailer hitch
receiver (Fig. 68). This harness includes a second
take out with a trailer tow relay connector bank and
four trailer tow relays that isolate the right turn sig-
nal, left turn signal, and brake lamp circuits of the
vehicle from the electrical system of the trailer. The
fourth relay in the connector bank provides a fused
ignition switch output (run) source of battery current
to the trailer tow connector through a trailer tow
relay output circuit. The package also includes an
adapter harness (stored beneath the left rear seat
cushion of the vehicle when it is shipped from the
factory) that adapts the 7-pin trailer tow connector to
a standard, light-duty, 4-pin trailer tow connector.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
Fig. 67 Trailer Tow Relay Remove/Install
1 - RELAY CONNECTOR BANK
2 - REAR BODY WIRE HARNESS
3 - LEFT TURN RELAY
4 - RIGHT TURN RELAY
5 - BRAKE LAMP RELAY
6 - FUSED IGNITION SWITCH OUTPUT (RUN) RELAY
Fig. 68 Trailer Tow Wiring
1 - RETAINER CLIP (4)
2 - REAR BODY HARNESS (TRAILER TOW TAKE OUT)
3 - RETAINER CLIP (2)
4 - WIRE HARNESS CONNECTOR
8Ls - 64 LAMPSKJ
TRAILER TOW RELAY (Continued)

LAMP BAR
DESCRIPTION
The lamp bar is used to better illuminate the driv-
ers field of vision under certain driving conditions. It
consists of a cover, two or four lamp assemblies
(depending upon which market), and a wiring har-
ness. These components are mounted to a reinforce-
ment, then sealed and secured to the roof panel.
Lamp bar illumination is controlled by a manually
operated momentary rocker switch, mounted to the
instrument panel. The lamps are adjustable in the
vertical position only.
OPERATION
Battery and ignition voltage are supplied to the
lamp bar switch assembly. When the switch is in the
on position the internal relay contacts close, complet-
ing the circuit through the lamp bar bulbs, to
ground. The lamp bar assembly is grounded to the
chassis. The hard wired circuits of the lamp bar may
be diagnosed and tested using conventional methods
and procedures.
DIAGNOSIS AND TESTING - LAMP BAR
CONDITION POSSIBLE CAUSES CORRECTION
LAMP BAR LAMPS
INOPERATIVEFaulty or missing fuse Test and replace lamp bar fuse
as required
Faulty feed circuit Test and repair open battery or
ignition feed circuit.
Faulty ground circuit Test and repair high resistance
or open lamp bar ground circuit
Faulty lamp bar sense circuit Test and repair short to voltage
in lamp bar sense circuit
Faulty switch Test and replace lamp bar
switch
LAMP BAR LAMPS ON AT
ALL TIMESFaulty switch Test and replace lamp bar
switch
Lamp bar feed circuit Test and repair short to voltage
in lamp bar feed circuit
ONE OR MORE LAMPS
INOPERATIVEFaulty or missing bulb Test and repair lamp bar lamp
bulb(s) as required
Faulty lamp bar wiring harness Test and repair short/open lamp
bar wiring harness
STANDARD PROCEDURE - LAMP BAR AIMING
NOTE: The lamp bar lamps are adjustable to the
vertical position only.
(1) Remove lamp bar cover.
(2) Using a fairly dark and level area, drive the
vehicle perpendicular to and 25 ft. away from a wall.
(3) Measure up the wall 7ft. 9in. and place tape on
the wall parallel to the ground.
(4) Turn on the lamp bar lamps.
(5) Using the adjustment screw in the rear of each
lamp, adjust the lamp beam to the center of the tape.
REMOVAL
REMOVAL - LAMP BAR
(1) Disconnect the negative battery cable.
(2) Remove the lamp bar cover retaining screws,
slide the cover forward and up to remove.
(3) Disconnect lamp electrical connector.
(4) Remove the lamp bar reinforcement to roof
stud retainers.
CAUTION: The reinforcement is held to the roof by
protective tape. Remove the tape carefully to pre-
vent damage to roof panel. After removal, the area
must be cleaned with the appropriate solvent.
KJLAMPS8Ls-65

(5) Remove lamp bar reinforcement from roof.
REMOVAL - LAMP
(1) Disconnect negative battery cable.
(2) Remove the lamp bar cover screws, slide the
cover forward and up to remove (Fig. 69).
NOTE: There is a hook arrangement for the forward
lamp attachment. Pick the lamp up by the bulb con-
nector.
(3) Remove the lamp to base retaining screws.
(4) Lift the lamp up and slide backward to remove.
INSTALLATION
INSTALLATION - LAMP BAR
NOTE: Lamp bar is held to roof by protective tape.
Mounting area must be clean and dry before instal-
lation.
(1) Remove tape protective strips on new lamp bar.
(2) Position lamp bar over roof studs (Fig. 69).
(3) Press the lamp bar reinforcement into place
making sure the tape strips are securely seated on
roof.
(4) Install the reinforcement nuts and tighten to
20 lbs. in.
(5) Connect electrical connector.
(6) Reconnect negative battery cable.
(7) Aim lamps (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/LAMP BAR - STANDARD
PROCEDURE) .
(8) Position the cover over lamp bar, slide rear-
ward and secure with screws.
INSTALLATION - LAMP
NOTE: There is a hook arrangement for the forward
lamp attachment. Pick the lamp up by the bulb con-
nector.
(1) Position the lamp assembly on the base (Fig.
69).
(2) Slide the lamp forward and seat.
(3) Install the lamp retaining screws.
(4) Reconnect negative battery cable.
(5) Align the lamps (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/LAMP BAR -
STANDARD PROCEDURE).
(6) Install the lamp bar cover.
Fig. 69 LAMP BAR
1 - Cover
2 - Electrical Connector
3 - Lamp Bar
8Ls - 66 LAMPSKJ
LAMP BAR (Continued)

LAMP BAR SWITCH
DESCRIPTION
The lamp bar switch is intended to close the elec-
trical circuit which feeds the lamp bar. The switch
assembly contains a relay unit that is energized or
de-energized by a manually operated momentary
rocker switch. The switch is mounted on the instru-
ment panel left of the steering wheel.
REMOVAL
CAUTION: Care must be taken not to damage the
dash or instrument panel when removing the lamp
bar switch bezel.
(1) Disconnect negative battery cable.
(2) Using a suitable pry tool, carefully remove the
lamp bar switch bezel from the instrument panel.
(3) Disconnect the electrical connector.
(4) Depress the lamp bar switch retaining tabs and
remove the switch from the bezel.
INSTALLATION
(1) Press the lamp bar switch into the instrument
panel bezel and assure that the switch is seated
properly (Fig. 70).
(2) Connect the electrical connector.
(3) Press the instrument panel bezel into position
and seat the bezal retaining clips.(4) Reconnect negative battery cable.
Fig. 70 LAMP BAR SWITCH
1 - Bezel
2 - Lamp Bar Switch
KJLAMPS8Ls-67

MESSAGE SYSTEMS
TABLE OF CONTENTS
page page
OVERHEAD CONSOLE
DESCRIPTION..........................1
OPERATION............................2
STANDARD PROCEDURE
STANDARD PROCEDURE - CMTC LAMP
REPLACEMENT.......................2
STANDARD PROCEDURE - COURTESY
LAMP REPLACEMENT..................2
STANDARD PROCEDURE - COMPASS
CALIBRATION.........................2
STANDARD PROCEDURE - COMPASS
DEMAGNETIZING......................2
STANDARD PROCEDURE - COMPASS
VARIATION ADJUSTMENT................3
REMOVAL
OVERHEAD CONSOLE - REMOVAL........4
INSTALLATION..........................4
COMPASS/MINI-TRIP COMPUTER
DESCRIPTION..........................4
OPERATION............................5
DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER..................6REMOVAL.............................7
INSTALLATION..........................8
UNIVERSAL TRANSMITTER
DESCRIPTION..........................8
OPERATION............................8
DIAGNOSIS AND TESTING - UNIVERSAL
TRANSMITTER........................8
STANDARD PROCEDURE
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES..................8
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES..................9
AMBIENT TEMP SENSOR
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR................9
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT.........9
REMOVAL.............................10
INSTALLATION.........................10
OVERHEAD CONSOLE
DESCRIPTION
An overhead console is standard factory-installed
equipment on this model. The available overheadconsoles can include the Compass Mini-Trip Com-
puter with universal transmitter (Fig. 2), without the
universal transmitter (Fig. 1), or base console with
only two reading and courtesy lamps (Fig. 3). All
overhead consoles are equipped with two reading and
courtesy lamps. On vehicles equipped with a power
Fig. 1 Overhead Console Without Universal
Transmitter
Fig. 2 Overhead Console With Universal Transmitter
KJMESSAGE SYSTEMS 8M - 1

sunroof, the sunroof switch is located between the
two reading and courtesy lamps. The overhead con-
sole is mounted with one screw and two snap clips to
a molded plastic retainer bracket located above the
headliner.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
STANDARD PROCEDURE
STANDARD PROCEDURE - CMTC LAMP
REPLACEMENT
(1) Open hood, disconnect and isolate the negative
battery cable.
(2) Remove overhead console (Refer to 8 - ELEC-
TRICAL/OVERHEAD CONSOLE - REMOVAL).
(3) Using a flat blade screwdriver twist out the
lamp socket.
(4) Replace lamp(s) as necessary.
STANDARD PROCEDURE - COURTESY LAMP
REPLACEMENT
(1) Open hood, disconnect and isolate the negative
battery cable.
(2) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(3) Remove the lamp and socket assembly from the
overhead console.
(4) Remove the lamp bulb by pulling it straight
out of its socket.
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
service replacement Compass Mini-Trip Computer
(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 C/T
push button to reach the compass/thermometer dis-
play.
(2) Depress the Reset push button and hold the
button down until ªCALº appears in the display. This
takes about ten seconds, and appears about five sec-
onds after ªVARIANCE = XXº is displayed.
(3) Release the Reset push button.
(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 ªCALº message will
disappear from the display to indicate that the com-
pass 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.
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
Fig. 3 Base Console
8M - 2 MESSAGE SYSTEMSKJ
OVERHEAD CONSOLE (Continued)

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 to an electrical
outlet, while keeping the tool at least 61 centimeters
(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. 4). 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
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 8 - ELECTRICAL/OVERHEAD
CONSOLE - STANDARD PROCEDURE).
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 compassto 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.
5).
(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) Depress the Reset push button and hold the
button down until ªVARIANCE = XXº appears in the
display. This takes about five seconds.
(4) Release the Reset push button. ªVARIANCE
=XX º will remain in the display. ªXXº equals the cur-
rent variance 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 CMTC module memory.
(7) Confirm that the correct directions are now
indicated by the compass.
Fig. 4 Roof Demagnetizing Pattern
KJMESSAGE SYSTEMS 8M - 3
OVERHEAD CONSOLE (Continued)

REMOVAL
OVERHEAD CONSOLE - REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the overhead console retaining screw,
located in the front of console near the windshield.
(3) Using your fingertips, grasp the sides of the
overhead console and pull straight down evenly to
disengage the two snap clips at the rear of the unit.
(4) Lower the overhead console far enough to
access the wire harness connectors.
(5) Disconnect the control module, courtesy lamps
and power sunroof switch electrical connectors, if
equipped.
(6) Remove the overhead console assembly from
the vehicle.
INSTALLATION
(1) Position the overhead console in the vehicle
and connect the wire harness connectors.
(2) Connect the control module, courtesy lamps
and power sunroof switch electrical connectors, if
equipped.
(3) Grasp the sides of the overhead console and
push straight up evenly to engage the two snap clips
at the rear of the unit.
(4) Install the overhead console retaining screw,
located in the front of console near the windshield.
Torque the screw to 1.2 N´m (10 in. lbs.).
(5) Connect the negative battery cable.
COMPASS/MINI-TRIP
COMPUTER
DESCRIPTION
The Compass Mini-Trip Computer (CMTC) is
located in the overhead console on models equipped
with this option. The Compass Mini-Trip Computer
module features a large Vacuum Fluorescent Display
(VFD) screen for displaying information, and four
back-lit push button function switches labeled C/T
(compass/thermometer), RESET, STEP, and US/M
(United States/Metric Scale).
The Compass Mini-Trip Computer module contains
a central processing unit and interfaces with other
electronic modules in the vehicle over the Program-
mable Communications Interface (PCI) data bus net-
work. The PCI data bus network allows the sharing
of sensor information. This helps to reduce wire har-
ness 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 capabilities.
The Compass Mini-Trip Computer module contains
six informational displays which can be displayed
using the four outer buttons on the overhead console.
When the vehicle is first turned ON:
²CMTC blanks the display for a half second
²Displays whatever was being viewed when the
ignition was last turned OFF
Fig. 5 Variance Settings
8M - 4 MESSAGE SYSTEMSKJ
OVERHEAD CONSOLE (Continued)