ignition JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

switch module housing is the hazard switch circuitry
and an electronic circuit board with the integral com-
bination flasher circuitry. The electronic combination
flasher circuitry performs both the hazard flasher
and turn signal flasher functions.
The hazard switch module cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The hazard switch button is slightly recessed in
the instrument panel when the switch is in the Off
position, and latches at a position that is flush with
the outer surface of the instrument panel when in
the On position. The hazard switch module produces
an audible clicking sound that emulates the sound of
a conventional flasher whenever the turn signals or
the hazard warning system are activated. The hazard
switch module receives battery current on a fused
B(+) circuit from a fuse in the Junction Block (JB) at
all times for operation of the hazard warning, and on
a fused ignition switch output (run) circuit from
another fuse in the JB whenever the ignition switch
is in the On position for operation of the turn signals.
The module receives a path to ground through a
splice block located in the instrument panel wire har-
ness with an eyelet terminal connector that is
secured by a nut to a ground stud on the driver side
instrument panel end bracket near the JB. Inputs to
and outputs from the hazard switch module include:
²Panel Lamps Dimmer Input- A non-service-
able incandescent bulb soldered onto the hazard
switch module circuit board provides illumination of
the switch button when the exterior lighting is
turned On through an input received on the fusedpanel lamps dimmer switch signal circuit. However,
this bulb flashes on and off at full intensity whenever
the hazard switch button is in the On position,
regardless of the status of the exterior lighting.
²Hazard Switch Input- The combination
flasher circuitry of the hazard switch module receives
an internal ground input from the hazard switch to
request hazard flasher operation.
²Multi-Function Switch Input- The combina-
tion flasher circuitry of the hazard switch module
receives separate ground inputs from the turn signal
switch circuitry of the multi-function switch on right
and left turn switch sense circuits to request right or
left turn signal flasher operation.
²Body Control Module Input- The Body Con-
trol Module (BCM) can request hazard flasher opera-
tion by providing a ground path to the combination
flasher circuitry of the hazard switch module through
a hazard lamp control circuit.
²Turn Signal Output- The combination flasher
circuitry within the hazard switch module responds
to the flasher request inputs by energizing and
de-energizing two miniature relays on the module
circuit board. These relays control the switch output
through the right and left turn signal circuits. One
relay controls the right lamps, while the other con-
trols the left.
Because of active electronic elements within the
hazard switch module, it cannot be tested with con-
ventional automotive electrical test equipment. If the
hazard switch module is believed to be faulty, replace
the switch with a known good unit to confirm system
operation.
REMOVAL
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) Disconnect and isolate the battery negative
cable.
Fig. 21 Hazard Switch
1 - HAZARD SWITCH BUTTON
2 - SCREW (1)
3 - MOUNTING BRACKET TABS
KJLAMPS8Ls-29
HAZARD SWITCH (Continued)

²Parade Mode- The internal circuitry and hard-
ware of the multi-function switch left (lighting) con-
trol stalk provide detent switching for a parade mode
that maximizes the illumination intensity of all
instrument panel lighting for visibility when driving
in daylight with the exterior lamps turned on.
²Park Lamps- The internal circuitry and hard-
ware of the multi-function switch left (lighting) con-
trol stalk provide detent switching for the park
lamps.
²Rear Fog Lamps- For vehicles so equipped,
the internal circuitry and hardware of the multi-
function switch left (lighting) control stalk provide
detent switching for the optional rear fog lamps.
Rear fog lamps are optional only for vehicles manu-
factured for certain markets, where they are
required.
²Turn Signal Control- The internal circuitry
and hardware of the multi-function switch left (light-
ing) control stalk provide both momentary non-detent
switching and detent switching with automatic can-
cellation for both the left and right turn signal
lamps.
RIGHT CONTROL STALK The right (wiper) con-
trol stalk of the multi-function switch supports the
following functions and features:
²Continuous Front Wipe Modes- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide two continuous
front wipe switch positions, low speed or high speed.
²Continuous Rear Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide one continuous
rear wipe switch position.
²Front Washer Mode- The internal circuitry
and hardware of the multi-function switch right
(wiper) control stalk switch provide front washer sys-
tem operation.
²Front Wipe-After-Wash Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide a wipe-after-wash
mode.
²Front Wiper Mist Mode- The internal cir-
cuitry and hardware of the multi-function switch
right (wiper) control stalk provide a front wiper sys-
tem mist mode.
²Intermittent Front Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide an intermittent
front wipe mode with five delay interval positions.
²Intermittent Rear Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide one fixed interval
intermittent rear wipe mode switch position.²Rear Washer Mode- The internal circuitry and
hardware of the multi-function switch right (wiper)
control stalk provide rear washer system operation.
OPERATION
The multi-function switch uses a combination of
resistor multiplexed and conventionally switched out-
puts to control the many functions and features it
provides. The switch receives battery current on a
fused ignition switch output (run-acc) circuit from a
fuse in the Junction Block (JB) whenever the ignition
switch is in the On or Accessory positions. The switch
receives a path to ground at all times through a
splice block located in the instrument panel wire har-
ness with an eyelet terminal connector that is
secured by a nut to a ground stud on the driver side
instrument panel end bracket near the Junction
Block (JB). Following are descriptions of how each of
the two multi-function switch control stalks operate
to control the functions and features they provide.
LEFT CONTROL STALK The left (lighting) control
stalk of the multi-function switch operates as follows:
²Front Fog Lamps- For vehicles so equipped,
the control knob on the end of the multi-function
switch left (lighting) control stalk is pulled outward
to activate the optional front fog lamps. The control
knob is mechanically keyed so that it cannot be
pulled outward unless it is first rotated to turn on
the exterior lighting. The multi-function switch pro-
vides a resistor multiplexed output to the Body Con-
trol Module (BCM) on a fog lamp switch sense
circuit, and the BCM responds by energizing or de-
energizing the front fog lamp relay in the Junction
Block (JB) as required.
²Headlamps-
The control knob on the end of the
multi-function switch left (lighting) control stalk is
rotated forward (counterclockwise) to its second detent
position to activate the headlamps. The multi-function
switch provides a resistor multiplexed output to the
Body Control Module (BCM) on a headlamp switch
sense circuit, and the BCM responds by energizing or
de-energizing the selected low or high beam relay
(Daytime Running Lamp relay in Canadian vehicles)
in the Junction Block (JB) as required.
²Headlamp Beam Selection-The left (lighting)
control stalk of the multi-function switch is pulled
towards the steering wheel past a detent to actuate
the integral beam select switch circuitry. Each time the
control stalk is activated in this manner, the opposite
headlamp beam from what is currently selected will be
energized. The multi-function switch provides a ground
output to the Body Control Module (BCM) on a high
beam switch sense circuit, and the BCM responds by
energizing or de-energizing the selected low or high
beam relay (Daytime Running Lamp relay in Canadian
vehicles) in the Junction Block (JB) as required.
8Ls - 48 LAMPSKJ
MULTI-FUNCTION SWITCH (Continued)

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

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

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)

The CMTC may also be integrated with the Uni-
versal Transmitter. If so, your CMTC module will
have three buttons centered together between the
outer four buttons. Below the three buttons are cor-
responding dots to indicate which button you are
using.
The Compass Mini-Trip Computer includes the fol-
lowing display options:
²Compass and thermometer- provides the out-
side temperature and one of eight compass readings
to indicate the direction the vehicle is facing.
²Average fuel economy- shows the average
fuel economy since the last trip computer reset.
²Distance to empty- shows the estimated dis-
tance that can be travelled with the fuel remaining
in the fuel tank. This estimated distance is computed
using the average miles-per-gallon from the last 30
gallons of fuel used.
²Instant fuel economy- shows the present fuel
economy based upon the current vehicle distance and
fuel used information.
²Trip odometer- shows the distance travelled
since the last trip computer reset.
²Elapsed time- shows the accumulated igni-
tion-on time since the last trip computer reset.
²Blank screen- the CMTC compass/thermome-
ter/trip computer VFD is turned off.
If the vehicle is equipped with the optional Univer-
sal Transmitter transceiver, the CMTC will also dis-
play messages and an icon indicating when the
Universal Transmitter is being trained, which of the
three transmitter buttons is transmitting, and when
the transceiver is cleared.
Data input for all CMTC functions, including VFD
dimming level, is received through PCI data bus
messages. The CMTC module uses its internal pro-
gramming 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 CMTC module and the PCI
data bus.
The CMTC module cannot be repaired, and is
available for service only as a unit. This unit
includes the push button switches and the plastic
module and display lens. If any of these components
is faulty or damaged, the complete CMTC module
must be replaced. The incandescent bulbs used for
CMTC push button back-lighting are available for
service replacement.
DESCRIPTION - COMPASS
While in the compass/thermometer mode, the com-
pass will display the direction in which the vehicle ispointed 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 prove
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, in not less than forty-eight
seconds. This will reorient the compass unit to its
vehicle.
The compass unit also will compensate for magne-
tism the body of the vehicle may acquire during nor-
mal 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 pro-
cession flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Mag-
netic 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 procedures found in this group may be
required to restore proper compass operation.
DESCRIPTION - THERMOMETER
The thermometer displays the outside ambient
temperature in whole degrees. The temperature dis-
play can be toggled from Fahrenheit to Celsius by
using the U.S./Metric button. The displayed temper-
ature is not an instant reading of conditions, but an
average temperature. It may take the thermometer
display several minutes to respond to a major tem-
perature change, such as driving out of a heated
garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the Body Control Module (BCM) unit memory. When
the ignition switch is turned to the On position
again, the CMTC will display the memory tempera-
ture for one minute; then update the display to the
current average temperature reading 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
Body Control Module (BCM). The BCM sends tem-
perature status messages to the CMTC module over
the PCI data bus network. The ambient temperature
sensor is available as a separate service item, refer to
additional information later in this section.
OPERATION
The compass mini-trip computer operates when the
ignition is in the ON position. The VFD will display
the last display before ignition was turned OFF. The
four outer buttons operate:
KJMESSAGE SYSTEMS 8M - 5
COMPASS/MINI-TRIP COMPUTER (Continued)

²STEP
²C/T - Compass/Temperature
²US/M - English/Metric
²RESET
1. STEP BUTTON
Pressing the STEP button selects one of the follow-
ing 6 displays:
²Average fuel economy
²Distance to empty
²Instantaneous fuel economy
²Trip odometer
²Elapsed time
²Blank Screen
2. C/T (COMPASS/TEMPERATURE)
BUTTON
Pressing the C/T button selects the Compass/Tem-
perature display.
3. US/M (ENGLISH/METRIC
MEASUREMENT) BUTTON
Pressing the US/M button switches the display
units between English and Metric readings.
4. RESET BUTTON
Pressing the RESET button resets the function on
the display, provided that function can be reset. The
functions which can be reset are Average fuel econ-
omy, Trip odometer and Elapsed time.
Global ResetThis feature allows all three dis-
plays (Average fuel economy, Trip odometer and
Elapsed time) to be reset easily, by pressing the
RESET button twice within three seconds with any
of the screens in display. This eliminates the need to
reset each display individually.
The RESET button is also used to set the variance
and/or calibrate the compass. Refer to the Variance
Procedure and Calibration Procedure in this section.
For more information on the features, control func-
tions and setting procedures for the CMTC module,
see the owner's manual in the vehicle glove box.
DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER
The following diagnostic procedure can be used if
the compass mini-trip computer is not operational in
any way. If the problem is specific to a individual
CMTC display, go to the appropriate display title
noted below and diagnose using the information pro-
vided on how these displays are generated.
(1) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(2) Using a ohmmeter, check the ground circuit
cavity of the compass mini-trip computer electricalconnector for proper continuity to ground. Continuity
should be present, If OK go to Step 3, If not OK
repair the open or shorted ground circuit as required.
NOTE: Connect the negative battery cable before
proceeding.
(3) Using a voltmeter, check the fused (B+) circuit
cavity of the compass mini-trip computer electrical
connector for 12v. Voltage should be present, If OK go
to Step 4, If not OK repair the open or shorted fused
(B+) circuit as required.
(4) Using a voltmeter, check the fused ignition
switch output circuit cavity of the compass mini-trip
computer electrical connector for 12v with Key ON.
Voltage should be present, If OK, replace the inoper-
ative CMTC module, If not OK repair the open or
shorted fused ignition switch output circuit as
required.
TEMPERATURE
The compass mini-trip computer receives Program-
mable Communications Interface bus (PCI bus) mes-
sages from the Body Control Module (BCM) for all
displayed information except the compass display. If
a dash (-) is displayed, the compass mini-trip com-
puter is not receiving a PCI bus message from the
BCM. To check out the PCI bus line and the BCM,
use the DRB llltscan tool and proper Body Diagnos-
tic Procedure Manual.
If the compass mini-trip computer displays a tem-
perature more than 54É C (130É F), check for a short
circuit between the temperature sensor and the
BCM.
If the compass mini-trip computer displays a tem-
perature less than -40É C (-67É F), check for an open
circuit between the temperature sensor and the
BCM.
AVERAGE FUEL ECONOMY
The compass mini-trip computer receives average
fuel economy information from the BCM over the PCI
bus line. If the compass mini-trip computer displays
-.- instead of an average fuel economy value, it is not
receiving a PCI bus message for the average fuel
economy from the BCM. To check out the PCI bus
line and the BCM use the DRB llltscan tool and
proper Body Diagnostic Procedure Manual.
DISTANCE TO EMPTY
The compass mini-trip computer receives distance
to empty information from the BCM over the PCI bus
line. If compass mini-trip computer displays a dash
(-) instead of a distance to empty value, it is not
receiving a PCI bus message for the distance to
empty from the BCM. To check out the PCI bus line
8M - 6 MESSAGE SYSTEMSKJ
COMPASS/MINI-TRIP COMPUTER (Continued)