2002 JEEP LIBERTY sensor

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)

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)

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)

(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the BCM wire harness connector.
There should be continuity. If OK, go to Step 4. If not
OK, repair the open sensor return circuit or ambient
temperature sensor signal circuit to the ambient tem-
perature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
return circuit cavity of the BCM wire harness con-
nector and a good ground. There should be no conti-
nuity. If OK, go to Step 5. If not OK, repair the
shorted sensor return circuit as required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the BCM wire
harness connector and a good ground. There should
be no continuity. If OK, refer toDiagnosis and
Testing - Compass Mini-Trip Computerin this
group. If not OK, repair the shorted ambient temper-
ature sensor signal circuit as required.REMOVAL
(1) Open hood, disconnect and isolate the negative
battery cable.
(2) Remove the grille from the vehicle (Refer to 23
- BODY/EXTERIOR/GRILLE - REMOVAL).
(3) Disconnect the ambient temperature sensor
electrical connector.
(4) Remove the ambient temperature sensor
retaining screw and remove the sensor from the vehi-
cle.
INSTALLATION
(1) Position the ambient temperature sensor and
install the retaining screw.
(2) Connect the ambient temperature sensor elec-
trical connector.
(3) Install the grille on the vehicle (Refer to 23 -
BODY/EXTERIOR/GRILLE - INSTALLATION).
(4) Connect the negative battery cable.
8M - 10 MESSAGE SYSTEMSKJ
AMBIENT TEMP SENSOR (Continued)

are closed and the accelerator pedal is depressed.
The rolling door lock feature can be disabled if
desired.
This vehicle also offers several customer program-
mable features, which allows the selection of several
optional electronic features to suit individual prefer-
ences.
The power lock system for this vehicle can also be
operated remotely using the available Remote Key-
less Entry (RKE) system radio frequency transmit-
ters, if equipped.
Certain functions and features of the power lock
system rely upon resources shared with other elec-
tronic modules in the vehicle over the Programmable
Communications Interface (PCI) data bus network.
For proper diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRBIIItscan
tool and the appropriate diagnostic information are
required.
REMOTE KEYLESS ENTRY
A Radio Frequency (RF) type Remote Keyless
Entry (RKE) system is an available factory-installed
option on this model. The RKE system allows the use
of a remote battery-powered radio transmitter to sig-
nal the Body Control Module (BCM) to actuate the
power lock system. The RKE receiver operates on
non-switched battery current through a fuse in the
Junction Block (JB), so that the system remains
operational, regardless of the ignition switch position.
The RKE transmitters are also equipped with a
Panic button. If the Panic button on the RKE trans-
mitter is depressed, the horn will sound and the
exterior lights will flash on the vehicle for about
three minutes, or until the Panic button is depressed
a second time. A vehicle speed of about 25.7 kilome-
ters-per-hour (15 miles-per-hour) will also cancel the
panic event.
The RKE system can also perform other functions
on this vehicle. If the vehicle is equipped with the
optional Vehicle Theft Security System (VTSS), the
RKE transmitter will arm the VTSS when the Lock
button is depressed, and disarm the VTSS when the
Unlock button is depressed.
The RKE system includes two transmitters when
the vehicle is shipped from the factory, but the sys-
tem can retain the vehicle access codes of up to four
transmitters. The transmitter codes are retained in
the RKE receiver memory, even if the battery is dis-
connected. If an RKE transmitter is faulty or lost,
new transmitter vehicle access codes can be pro-
grammed into the system using a DRBIIItscan tool.
This vehicle also offers several customer program-
mable features, which allows the selection of several
optional electronic features to suit individual prefer-ences. Customer programmable feature options
affecting the RKE system include:
²Remote Unlock Sequence- Allows the option
of having only the driver side front door unlock when
the RKE transmitter Unlock button is depressed the
first time. The remaining doors and the tailgate
unlock when the button is depressed a second time
within 5 seconds of the first unlock press. Another
option is having all doors and the tailgate unlock
upon the first depression of the RKE transmitter
Unlock button.
²Sound Horn on Lock- Allows the option of
having the horn sound a short chirp as an audible
verification that the RKE system received a valid
Lock request from the RKE transmitter, or having no
audible verification.
²Flash Lights with Lock and Unlock- Allows
the option of having the lights flash as an optical ver-
ification that the RKE system received a valid Lock
request or Unlock request from the RKE transmitter,
or having no optical verification.
²Programming Additional Transmitters-
Allows up to four transmitter vehicle access codes to
be stored in the receiver memory.
Certain functions and features of the RKE system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
PCI data bus network allows the sharing of sensor
information. This helps to reduce wire harness com-
plexity, internal controller hardware, and component
sensor current loads. For diagnosis of these electronic
modules or of the PCI data bus network, the use of a
DRBIIItscan tool and the appropriate diagnostic
information are required.
TAILGATE / FLIP-UP GLASS POWER RELEASE
SYSTEM
A power operated tailgate / flip-up glass release
system is standard factory installed equipment on
this model. The entire system is controlled by the
Body Control Module (BCM). The tailgate / flip-up
glass power release system allows the flip-up glass
latch to be released electrically by actuating a switch
located integral to the outside tailgate handle. By
pulling the handle to the first detent or turning the
key cylinder to unlock, the flip-up glass will open.
Pulling the handle to the second detent will allow the
tailgate to open.
The tailgate / flip-up glass release system operates
on non-switched battery current supplied through a
fuse in the junction block so that the system remains
functional, regardless of the ignition switch position.
However, the BCM prevents the flip-up glass latch
from being actuated when the tailgate latch is
locked.
8N - 2 POWER LOCKSKJ
POWER LOCKS (Continued)

RESTRAINTS
TABLE OF CONTENTS
page page
RESTRAINTS
DESCRIPTION..........................2
OPERATION............................4
WARNING - RESTRAINT SYSTEM...........5
DIAGNOSIS AND TESTING - SUPPLEMENTAL
RESTRAINT SYSTEM...................6
STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING
NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS.........................6
STANDARD PROCEDURE - SERVICE
AFTER A SUPPLEMENTAL RESTRAINT
DEPLOYMENT.........................6
STANDARD PROCEDURE - VERIFICATION
TEST................................8
AIRBAG CONTROL MODULE
DESCRIPTION..........................9
OPERATION...........................10
REMOVAL.............................11
INSTALLATION.........................12
CHILD TETHER ANCHOR
DESCRIPTION.........................13
OPERATION...........................13
CLOCKSPRING
DESCRIPTION.........................13
OPERATION...........................14
STANDARD PROCEDURE - CLOCKSPRING
CENTERING.........................14
REMOVAL.............................15
INSTALLATION.........................16
DRIVER AIRBAG
DESCRIPTION.........................17
OPERATION...........................18
REMOVAL.............................19
INSTALLATION.........................20
FRONT IMPACT SENSOR
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................22
INSTALLATION.........................22
FRONT SEAT BELT & RETRACTOR
REMOVAL.............................23
INSTALLATION.........................24FRONT SEAT BELT BUCKLE
REMOVAL.............................25
INSTALLATION.........................26
PASSENGER AIRBAG
DESCRIPTION.........................27
OPERATION...........................27
REMOVAL.............................28
INSTALLATION.........................29
PASSENGER AIRBAG DOOR
REMOVAL.............................29
INSTALLATION.........................30
PASSENGER AIRBAG MOUNTING BRACKET
REMOVAL.............................31
INSTALLATION.........................31
REAR CENTER SEAT BELT & RETRACTOR
REMOVAL.............................32
INSTALLATION.........................33
REAR OUTBOARD SEAT BELT & RETRACTOR
REMOVAL.............................33
INSTALLATION.........................34
REAR SEAT BELT BUCKLE
REMOVAL.............................34
INSTALLATION.........................35
SEAT BELT SWITCH
DESCRIPTION.........................35
OPERATION...........................36
SEAT BELT TENSIONER
DESCRIPTION.........................36
OPERATION...........................36
SEAT BELT TURNING LOOP ADJUSTER
REMOVAL.............................37
INSTALLATION.........................38
SIDE CURTAIN AIRBAG
DESCRIPTION.........................38
OPERATION...........................39
REMOVAL.............................40
INSTALLATION.........................41
SIDE IMPACT AIRBAG CONTROL MODULE
DESCRIPTION.........................43
OPERATION...........................43
REMOVAL.............................44
INSTALLATION.........................45
KJRESTRAINTS 8O - 1

RESTRAINTS
DESCRIPTION
Fig. 1 Supplemental Restraint System
1 - FRONT IMPACT SENSOR (2)
2 - AIRBAG CONTROL MODULE
3 - PASSENGER AIRBAG
4 - DRIVER AIRBAG5 - SIDE CURTAIN AIRBAG (2)
6 - DRIVER SEAT BELT TENSIONER
7 - SIDE IMPACT AIRBAG CONTROL MODULE (2)
8O - 2 RESTRAINTSKJ

An occupant restraint system is standard factory-
installed safety equipment on this model. Available
occupant restraints for this model include both active
and passive types. Active restraints are those which
require the vehicle occupants to take some action to
employ, such as fastening a seat belt; while passive
restraints require no action by the vehicle occupants
to be employed (Fig. 1).
ACTIVE RESTRAINTS The active restraints for
this model include:
²Front Seat Belts- Both front seating positions
are equipped with three-point seat belt systems
employing a lower B-pillar mounted inertia latch-
type retractor, height-adjustable upper B-pillar
mounted turning loops, a traveling lower seat belt
anchor secured to the outboard side of the seat
frame, and a traveling end-release seat belt buckle
secured to the inboard side of the seat frame. Both
front seat belt buckles include an integral Hall-effect
seat belt switch that detects whether its respective
seat belt has been fastened.
²Rear Seat Belts- All three rear seating posi-
tions are equipped with three-point seat belt sys-
tems. The outboard seating position belts employ a
lower C-pillar mounted inertia latch-type retractor, a
fixed position upper C-pillar mounted turning loop,
and a fixed lower seat belt anchor secured to the
floor panel. The rear seat center seating position belt
has an inertia latch-type retractor that is integral to
the rear seat back panel, and a cable from the seat
back latch locks the center belt retractor spool unless
the seat back is fully latched. The rear seat center
seating position belt lower anchor is secured to the
floor panel. All three rear seat belts have fixed end-
release seat belt buckles secured to the floor panel, a
single buckle unit on the right side and a double
buckle unit on the left side.
²Child Seat Tether Anchors- All vehicles are
equipped with three, fixed-position, child seat tether
anchors. Two anchors are integral to the back of the
right rear seat back panel, and one is integral to the
left rear seat back panel.
PASSIVE RESTRAINTS The passive restraints
available for this model include the following:
²Dual Front Airbags- Multistage driver and
front passenger airbags are available for this model.
This airbag system is a passive, inflatable, Supple-
mental Restraint System (SRS) and vehicles with
this equipment can be readily identified by the ªSRS
- AIRBAGº logo molded into the driver airbag trim
cover in the center of the steering wheel and also
into the passenger airbag door on the instrument
panel above the glove box (Fig. 2). Vehicles with the
airbag system can also be identified by the airbag
indicator, which will illuminate in the instrument
cluster for about seven seconds as a bulb test eachtime the ignition switch is turned to the On position.
A pyrotechnic-type seat belt tensioner is integral to
the driver side front seat belt retractor mounted on
the lower B-pillar of all models equipped with dual
front airbags.
²Side Curtain Airbags- Optional side curtain
airbags are available for this model when it is also
equipped with dual front airbags. This airbag system
is a passive, inflatable, Supplemental Restraint Sys-
tem (SRS) and vehicles with this equipment can be
readily identified by a molded identification trim but-
ton with the ªSRS - AIRBAGº logo located on the
headliner above each B-pillar (Fig. 2).
The supplemental restraint system includes the
following major components, which are described in
further detail elsewhere in this service information:
²Airbag Control Module- The Airbag Control
Module (ACM) is also sometimes referred to as the
Occupant Restraint Controller (ORC). The ACM is
located on a mount on the floor panel transmission
tunnel, below the center of the instrument panel.
²Airbag Indicator- The airbag indicator is inte-
gral to the ElectroMechanical Instrument Cluster
(EMIC), which is located on the instrument panel in
front of the driver.
²Clockspring- The clockspring is located near
the top of the steering column, directly beneath the
steering wheel.
²Driver Airbag- The driver airbag is located in
the center of the steering wheel, beneath the driver
airbag trim cover.
²Driver Knee Blocker- The driver knee blocker
is a structural unit secured to the back side of and
integral to the instrument panel steering column
opening cover.
²Front Impact Sensor- Two front impact sen-
sors are used on vehicles equipped with dual front
airbags, one left side and one right side. One sensor
Fig. 2 SRS Logo
KJRESTRAINTS 8O - 3
RESTRAINTS (Continued)