Light JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

REAR LAMP BULB
REMOVAL
The rear lamp unit may contain up to four bulbs,
depending upon the market for which the vehicle was
manufactured. The service procedures for each bulb
is the same, only the bulb sizes and types may differ.
Be certain any removed bulb is replaced with the
same bulb size and type that was removed.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear lamp unit from the end of the
quarter panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REAR LAMP UNIT -
REMOVAL).
(3) Firmly grasp the socket on the socket plate at
the back of the rear lamp unit housing for the bulb
that is being removed (Fig. 59).
(4) Rotate the socket on the socket plate at the
back of the rear lamp unit housing counterclockwise
about 30 degrees.
(5) Pull the socket and bulb straight out of the
back of the rear lamp unit housing.
(6) Pull the bulb straight out of the rear lamp unit
socket.
INSTALLATION
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.(1) Align the base of the bulb with the receptacle
in the rear lamp unit socket.
(2) Push the bulb straight into the rear lamp unit
socket until it is firmly seated.
(3) Align the socket and bulb with the opening in
the socket plate on the back of the rear lamp unit
housing (Fig. 59).
(4) Push the socket and bulb straight into the rear
lamp unit housing until the socket is firmly seated
against the socket plate.
(5) Rotate the socket on the socket plate at the
back of the rear lamp unit housing clockwise about
30 degrees.
(6) Reinstall the rear lamp unit onto the end of the
quarter panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REAR LAMP UNIT -
INSTALLATION).
(7) Reconnect the battery negative cable.
REAR LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Open the tailgate to access and remove the two
screws that secure the inboard side of the rear lamp
unit to the side jamb of the tailgate opening (Fig. 60).
(3) Pull the outboard side of the rear lamp unit
rearward (away from the end of the quarter panel)
far enough to unsnap the two ball studs on the out-
board side of the lamp housing from the plastic nuts
in the quarter panel.
Fig. 59 Rear Lamp Bulb Remove/Install
1 - REAR LAMP HOUSING
2 - BULB HOLDER
3 - BULB
4 - SOCKET PLATE
Fig. 60 Rear Lamp Unit Remove/Install
1 - PLASTIC NUT (2)
2 - WIRE HARNESS CONNECTOR
3 - PLASTIC NUT (2)
4 - REAR LAMP UNIT
5 - SCREW (2)
KJLAMPS8Ls-59

(4) Pull the rear lamp unit away from the quarter
panel far enough to access and disconnect the wire
harness connector for the lamp unit from the connec-
tor receptacle on the lamp socket plate.
(5) Remove the rear lamp unit from the quarter
panel.
(6) Remove the plastic nuts from the quarter panel
and discard.
INSTALLATION
(1) Install new plastic nuts into the quarter panel
(Fig. 60).
(2) Position the rear lamp unit to the quarter
panel.
(3) Reconnect the wire harness connector for the
rear lamp unit to the connector receptacle on the
lamp socket plate.
(4) Align the two ball studs on the outboard side of
the rear lamp unit housing with the plastic nuts in
the quarter panel.
(5) Using hand pressure, push the outboard side of
the rear lamp unit forward (towards the end of the
quarter panel) far enough to snap the two ball studs
on the outboard side of the lamp housing into the
plastic nuts in the quarter panel.
(6) Align the mounting holes on the inboard side of
the rear lamp unit housing with the plastic nuts in
the side jamb of the tailgate opening.
(7) Install and tighten the two screws that secure
the inboard side of the rear lamp unit housing to the
plastic nuts in the side jamb of the tailgate opening.
Tighten the screws to 2 N´m (20 in. lbs.).
(8) Reconnect the battery negative cable.
REPEATER LAMP BULB
REMOVAL
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the repeater lamp unit from the front
fender panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REPEATER LAMP UNIT -
REMOVAL).
(3) Rotate the repeater lamp socket in the lamp
lens counterclockwise about 30 degrees (Fig. 61).
(4) Pull the socket and bulb straight out of the
repeater lamp lens.
(5) Pull the bulb straight out of the repeater lamp
socket.
INSTALLATION
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
(1) Align the base of the bulb with the receptacle
in the repeater lamp socket.
(2) Push the bulb straight into the repeater lamp
socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing in the repeater lamp lens (Fig. 61).
(4) Push the socket and bulb straight into the
repeater lamp lens until it is firmly seated
(5) Rotate the repeater lamp socket in the lamp
lens clockwise about 30 degrees.
(6) Reinstall the repeater lamp unit onto the front
fender panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REPEATER LAMP UNIT -
INSTALLATION).
(7) Reconnect the battery negative cable.
Fig. 61 Repeater Lamp Bulb Remove/Install
1 - FRONT FENDER
2 - SOCKET
3 - BULB
4 - LENS
8Ls - 60 LAMPSKJ
REAR LAMP UNIT (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

(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)

(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)

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)

and the BCM use the DRB llltscan tool and proper
Body Diagnostic Procedure Manual.
INSTANTANEOUS FUEL ECONOMY
The compass mini-trip computer receives instanta-
neous fuel economy information from the BCM over
the PCI bus line. If compass mini-trip computer dis-
plays a dash (-) instead of an instantaneous fuel
economy value, it is not receiving a PCI bus message
for the instantaneous fuel economy from the BCM. To
check out the PCI bus line and the BCM use the
DRB llltscan tool and proper Body Diagnostic Pro-
cedure Manual.
TRIP ODOMETER
The compass mini-trip computer receives trip
odometer information from the Cluster over the PCI
bus line. If compass mini-trip computer displays
dashes - - instead of the trip odometer value, it is not
receiving a PCI bus message for the trip odometer
from the cluster. To check out the PCI bus line and
the Cluster, use the DRB llltscan tool and proper
Body Diagnostic Procedure Manual.
ELAPSED TIME
The compass mini-trip computer receives a PCI
bus message containing elapsed time information. If
compass mini-trip computer displays dashes --
instead of the elapsed time, it is not receiving a PCI
bus message for the elapsed time from the BCM. To
check out the PCI bus line and the BCM, use the
DRB llltscan tool and proper Body Diagnostic Pro-
cedure Manual.
COMPASS DISPLAY
To display the vehicle direction, the compass mini-
trip computer processes information from a sensor
internal to the module. The compass mini-trip com-
puter is self- calibrating and requires only variance
adjustments dependent upon location. The compass
mini-trip computer displays the label CAL whenever
the compass is in the fast calibration mode.
If all three of the following conditions listed below
occur, the vehicle must be demagnetized.
²Compass portion of the display is blank
²Temperature portion of the display is OK
²The label CAL is illuminated
If demagnetizing the vehicle is needed, refer to the
demagnetizing procedure in this section. After
demagnetizing, to calibrate the compass refer to Cal-
ibration Procedure and to set the variance refer to
Variance Procedure, both within this section. If the
compass portion of the display is still blank, replace
the compass mini-trip computer.
COMPASS MINI-TRIP COMPUTER - SELF
DIAGNOSTIC TEST
(1) With the ignition switch in the OFF position
simultaneously press the C/T and STEP buttons and
hold.
(2) Turn the ignition switch ON, then release C/T
and STEP buttons.
(3) The Compass mini-trip computer should light
all segments on the VF Display Screen for 2-4 sec-
onds. Check for segments that are not illuminated.
(4) If the compass mini-trip computer displays
PASS, the module is OK.
(5) If the compass mini-trip computer displays
FAIL, replace the module.
(6) If the compass mini-trip computer displays
bUS, check for an open or a short on the PCI bus
communication circuit.
(7) Press the C/T or the STEP button to exit the
self-diagnostic test.
REMOVAL
(1) Remove overhead console, refer to Console
Removal and Installation in this section.
(2) Remove mounting screws and release the map
lamp wire connector from the compass mini-trip com-
puter. (Fig. 6).
Fig. 6 Compass Mini-Trip Computer Retaining
Screws
1 - LAMPS
2 - MOUNTING SCREWS
KJMESSAGE SYSTEMS 8M - 7
COMPASS/MINI-TRIP COMPUTER (Continued)

(3) Remove the compass mini-trip computer from
the overhead console.
INSTALLATION
(1) Install the compass mini-trip computer in the
overhead console. Align the compass mini-trip com-
puter guides on the housing with the grooves of the
console.
(2) Install the mounting screws and install the
map lamp wire connector on the compass mini-trip
computer. Make sure the LOOP of wire that was
clipped into the compass mini-trip computer module
housing is properly clipped into the new module
before the console is placed back into the headliner.
(3) Install the overhead console, refer to Console
Installation in this section.
UNIVERSAL TRANSMITTER
DESCRIPTION
On some KJ models a Universal Transmitter trans-
ceiver is standard factory-installed equipment. The
universal transmitter transceiver is integral to the
Compass Mini-Trip Computer (CMTC), which is
located in the overhead console. The only visible com-
ponent of the universal transmitter are the three
transmitter push buttons (Fig. 7) centered between
the four CMTC push buttons located just rearward of
the CMTC display screen in the overhead console.
The three universal transmitter 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 universal transmitter push but-
tons controls an independent radio transmitter chan-
nel. Each of these three channels can be trained totransmit 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 universal transmitter is capable of operat-
ing systems using either rolling code or non-rolling
code technology.
The CMTC module displays messages and a small
house-shaped icon with one, two or three dots corre-
sponding to the three transmitter buttons to indicate
the status of the Universal Transmitter.
The Universal Transmitter cannot be repaired, and
is available for service only as a unit with the CMTC
module. 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.
OPERATION
The universal transmitter operates 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, pro-
gramming procedures and operation of the universal
transmitter, see the owner's manual in the vehicle
glove box.
DIAGNOSIS AND TESTING - UNIVERSAL
TRANSMITTER
If the Universal Transmitter is inoperative, but the
Compass Mini-Trip Computer (CMTC) is operating
normally, see the owner's manual in the vehicle glove
box for instructions on training the universal trans-
mitter. Retrain the universal transmitter with a
known good transmitter as instructed in the owner's
manual and test the universal transmitter operation
again. If the unit is still inoperative, replace the
faulty universal transmitter and CMTC module as a
unit. If both the universal transmitter and the CMTC
module are inoperative, refer toDiagnosis and
Testing the Compass Mini-Trip Computerin this
section for further diagnosis. For complete circuit
diagrams, refer toOverhead Consolein Wiring
Diagrams.
STANDARD PROCEDURE
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES
To erase the universal transmitter codes, simply
hold down buttons 1 and 3 until the two green dots
below the house symbol begin to flash.
Fig. 7 Overhead Console With Universal Transmitter
8M - 8 MESSAGE SYSTEMSKJ
COMPASS/MINI-TRIP COMPUTER (Continued)

NOTE: Individual channels cannot be erased. Eras-
ing the transmitter codes will erase ALL pro-
grammed codes.
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES
(1) Turn off the engine.
(2) Erase the factory test codes by pressing but-
tons 1 and 3. Release the buttons when the two
green lights begin to flash (about 20 seconds).
(3) Choose one of the three buttons to train. Place
the hand-held transmitter within one inch of the uni-
versal transmitter and push the buttons on both
transmitters. The green dot below the house symbol
will begin to flash slowly.
(4) When the red light on the universal transmit-
ter begins to flash rapidly (this may take as long as
60 seconds), release both buttons. Your universal
transmitter is now ªtrainedº. To train the other but-
tons, repeat Step 3 and Step 4. Be sure to keep your
hand-held transmitter in case you need to retrain the
universal transmitter.
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the Com-
pass Mini-Trip Computer (CMTC) through ambient
temperature sensor messages received from the Body
Control Module (BCM) over the Programmable Com-
munications Interface (PCI) data bus network. The
BCM receives a hard wired input from the ambient
temperature sensor. The ambient temperature sensor
(Fig. 8) is a variable resistor mounted in front the
radiator, behind the grille, near the center of the
vehicle.
Refer toBody Control Modulein Electronic Con-
trol Modules. For complete circuit diagrams, refer to
the appropriate wiring information. The ambient
temperature sensor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the BCM. The resistance in the sensor
changes as temperature changes, changing the tem-
perature sensor signal circuit voltage to the BCM.
Based upon the resistance in the sensor, the BCM
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The BCM then sends the
proper ambient temperature messages to the CMTC
over the PCI data bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Body Control Module (BCM), the Programmable
Communications Interface (PCI) data bus, and a por-
tion of the Compass Mini-Trip Computer module.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Compass Mini-Trip Computerin this
section. For complete circuit diagrams, refer to the
appropriate wiring information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336 kilohms. At 55É C (140É F), the sensor
resistance is 2.488 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Body Control Module wire
harness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
Fig. 8 Ambient Temperature Sensor
KJMESSAGE SYSTEMS 8M - 9
UNIVERSAL TRANSMITTER (Continued)