2002 JEEP LIBERTY Body

proper Diagnostic Procedures manual. The
DRBIIItscan tool can provide confirmation
that the PCI data bus is functional, that all of
the electronic modules are sending and receiv-
ing the proper messages on the PCI data bus,
and that the power lock motors are being sent
the proper hard wired outputs by the relays for
them to perform their power lock system func-
tions.
Following are tests that will help to diagnose the
hard wired components and circuits of the power lock
system. However, these tests may not prove conclu-
sive in the diagnosis of this system. In order to
obtain conclusive testing of the power lock system,
the Programmable Communications Interface (PCI)
data bus network and all of the electronic modules
that provide inputs to, or receive outputs from the
power lock system components must be checked.
The Body Control Module (BCM) will set Diagnos-
tic Trouble Codes (DTC) for the power lock system.
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.
PRELIMINARY DIAGNOSIS
As a preliminary diagnosis for the power lock sys-
tem, note the system operation while you actuate
both the Lock and Unlock functions with the power
lock switches and with the Remote Keyless Entry
(RKE) transmitter. Then, proceed as follows:
²If the entire power lock system fails to function
with either the power lock switches or the RKE
transmitter, check the fused B(+) fuse in the junction
Block (JB).
²If the power lock system functions with both
power lock switches, but not with the RKE transmit-
ter, proceed to diagnosis of the Remote Keyless Entry
(RKE) system. (Refer to 8 - ELECTRICAL/POWER
LOCKS/KEYLESS ENTRY TRANSMITTER - DIAG-
NOSIS AND TESTING) or (Refer to 8 - ELECTRI-
CAL/POWER LOCKS/REMOTE KEYLESS ENTRY
MODULE - DIAGNOSIS AND TESTING).
²If the power lock system functions with the RKE
transmitter, but not with one or both power lock
switches, proceed to diagnosis of the door lock
switches. (Refer to 8 - ELECTRICAL/POWER
LOCKS/POWER LOCK SWITCH - DIAGNOSIS AND
TESTING).
²If the driver side power lock switch operates
only the driver side front door power lock motor, but
all other power lock motors operate with the passen-
ger side power lock switch or the RKE transmitter,
use a DRBIIItscan tool and the appropriate diagnos-tic information to diagnose the Programmable Com-
munications Interface (PCI) data bus.
²If only one power lock motor fails to operate
with both power lock switches and the RKE trans-
mitter, proceed to diagnosis of the power lock motor.
(Refer to 8 - ELECTRICAL/POWER LOCKS/POWER
LOCK MOTOR - DIAGNOSIS AND TESTING).
DOOR LOCK / UNLOCK
SWITCH
DIAGNOSIS AND TESTING - DOOR LOCK/
UNLOCK SWITCH
(1) Remove the switch to be tested (Refer to 8 -
ELECTRICAL/POWER LOCKS/POWER LOCK
SWITCH - REMOVAL).
(2) Using an ohmmeter, Test switch for resistance
values (Fig. 1).
DOOR LOCK SWITCH TEST
SWITCH
POSITIONPINS RESISTANCE
VALUE
UNACTUATED 1 AND 4 5.0K OHM   10
%
LOCK 1 AND 4 1.4K OHM  10
%
UNLOCK 1 AND 4 426 OHM   10
%
(3) If test results are not obtained as shown in the
test table, replace the switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Fig. 1 DOOR LOCK/UNLOCK SWITCH
8N - 4 POWER LOCKSKJ
POWER LOCKS (Continued)

(2) Remove the door trim panel (Fig. 2) (Refer to
23 - BODY/DOOR - FRONT/TRIM PANEL - REMOV-
AL).
(3) Disconnect electrical harness connector from
switch.
(4) From behind the door trim panel, gently pry
the switch from the door trim panel (Fig. 3).
INSTALLATION
(1) Press the switch into place.
(2) Connect the electrical harness connector to the
switch.(3) Install the door trim panel (Refer to 23 -
BODY/DOOR - FRONT/TRIM PANEL - INSTALLA-
TION).
(4) Connect the battery negative cable.
DOOR LOCK MOTOR
DESCRIPTION
The lock mechanisms are actuated by a reversible
electric motor mounted within each door and tailgate.
The power lock motors are integral to the door latch
units.
The power lock motors cannot be adjusted or
repaired and, if faulty or damaged, the door latch
unit must be replaced.
OPERATION
The door lock motors are controlled by relays. A
positive and negative battery connection to the two
motor terminals will cause the motor to move in one
direction. Reversing the current will cause the motor
to move in the opposite direction.
DIAGNOSIS AND TESTING - DOOR LOCK
MOTOR
The most reliable, efficient, and accurate means to
diagnose the power lock system requires the use of a
DRBIIItscan tool and the proper Diagnostic Proce-
dures manual. The DRBIIItscan tool can provide
confirmation that the PCI data bus is functional, that
all of the electronic modules are sending and receiv-
ing the proper messages on the PCI data bus, and
that the power lock motors are being sent the proper
hard wired outputs by the door modules for them to
perform their power lock system functions.
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.
FLIP-UP GLASS RELEASE
SWITCH
DIAGNOSIS AND TESTING - FLIP-UP GLASS
RELEASE SWITCH
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the tailgate trim panel (Refer to 23 -
BODY/DECKLID/HATCH/LIFTGATE/TAILGATE/
TRIM PANEL - REMOVAL).
(3) Disconnect the wire harness connector.
Fig. 2 DOOR LOCK SWITCH
1 - DOOR TRIM PANEL
2 - DOOR LOCK SWITCH
3 - POWER MIRROR SWITCH
Fig. 3 DOOR LOCK/MIRROR SWITCH
1 - DOOR TRIM PANEL
2 - DOOR LOCK SWITCH
3 - POWER MIRROR SWITCH
KJPOWER LOCKS 8N - 5
DOOR LOCK / UNLOCK SWITCH (Continued)

(4) Using an ohmmeter, check for continuity
between the pins of the wire harness connector while
pulling on the tailgate handle.
(5) If no continuity is found, replace the tailgate
handle assembly (Refer to 23 - BODY/DECKLID/
HATCH/LIFTGATE/TAILGATE/EXTERIOR HAN-
DLE - REMOVAL).
DOOR LOCK RELAY
DESCRIPTION
The power door lock system uses the following
relays for the front and rear passenger doors only:
²Driver door unlock relay
²Door lock relay
²Passenger Doors unlock relay
The tailgate uses outputs from the Body Control
Module (BCM).
The relays are electromechanical devices that
switch battery current to the door lock circuit when
the Body Control Module (BCM) grounds the relay
coil. These relays are located in the Junction Block
(JB). For complete circuit diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
The relays are a International Standards Organi-
zation (ISO) micro-relay. Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The ISO micro-relay terminal functions
are the same as a conventional ISO relay. However,
the ISO micro-relay terminal pattern (or footprint) is
different, the current capacity is lower, and the phys-
ical dimensions are smaller than those of the conven-
tional ISO relay.
The relay cannot be repaired or adjusted and, if
faulty or damaged, it must be replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor and three (two fixed and one movable) elec-
trical contacts. The movable (common feed) relay con-
tact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor is connected in
parallel with the electromagnetic coil in the relay,
and helps to dissipate voltage spikes that are pro-
duced when the coil is de-energized.
DIAGNOSIS AND TESTING - DOOR LOCK
RELAY
The power lock relays (Fig. 4) are located in the
Junction Block (JB) under the instrument panel. For
complete circuit diagrams, 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.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove suspected faulty relay from the (JB).
(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 not OK, replace the faulty relay.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Reach up under instrument panel and remove
the relay from Junction Block (JB).
8N - 6 POWER LOCKSKJ
FLIP-UP GLASS RELEASE SWITCH (Continued)

INSTALLATION
(1) Position the horn relay in the proper receptacle
in the Junction Block (JB).
(2) Push down firmly on the relay until the termi-
nals are fully seated.
(3) Connect the battery negative cable.
REMOTE KEYLESS ENTRY
MODULE
DESCRIPTION
When an RKE lock message is sent to the Body
Control Module (BCM), the BCM actuates the doors
and the tailgate lock, the interior lighting is turned
off, the horn chirps (if this feature is enabled), the
exterior lamps flash (if this feature is enabled) and, if
the vehicle is so equipped, the Vehicle Theft Security
System (VTSS) is armed. When an RKE unlock mes-
sage is sent to the BCM, the BCM actuates the
driver side front door (or all doors and the tailgate if
this feature is enabled) unlock, the interior lighting
is turned on and, if the vehicle is so equipped, the
VTSS is disarmed.When an RKE panic message is sent to the BCM,
the BCM actuates the driver side front door (or all
doors and the tailgate if this feature is enabled)
unlock, the interior lighting is turned on and, if the
vehicle is so equipped, the VTSS is disarmed. The
panic message will also cause the exterior lamps
(including the headlights) to flash, and the horn to
pulse for about three minutes, or until a second panic
message is sent to the BCM. A vehicle speed of about
25.7 kilometers-per-hour (15 miles-per-hour) will also
cancel the panic event.
Refer to the owner's manual for more information
on the features, use and operation of the RKE sys-
tem.
OPERATION
Whenever the vehicle battery power is interrupted,
the Remote Keyless Module (RKE) Module will retain
all vehicle access codes in its memory. When replac-
ing or adding a key fob transmitter (maximum of 4) a
DRB IIItscan tool is required to program the RKE
Module to accept the new Vehicle Access Code if a
customer owned transmitter is not available.
If a functioning transmitter is available, (Refer to 8
- ELECTRICAL/POWER LOCKS/KEYLESS ENTRY
TRANSMITTER - STANDARD PROCEDURE)
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY MODULE
Refer to the appropriate wiring information. The
wiring 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. Refer to the
proper Body Diagnostic Procedures Manual for test-
ing the Remote Keyless Entry system using a DRB
IIItscan tool.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Junction Block (JB) (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/JUNCTION
BLOCK - REMOVAL).
(3) Remove Remote Keyless Entry module from
Body Control Module (Fig. 5).
INSTALLATION
(1) Install Remote Keyless Entry module to Body
Control Module.
(2) Install Junction Block (JB) (Refer to 8 - ELEC-
TRICAL/POWER DISTRIBUTION/JUNCTION
BLOCK - INSTALLATION).
(3) Connect the battery negative cable.
Fig. 4 Power Lock Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJPOWER LOCKS 8N - 7
DOOR LOCK RELAY (Continued)

REMOTE KEYLESS ENTRY
TRANSMITTER
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY TRANSMITTER
The most reliable, efficient, and accurate means to
diagnose the remote keyless entry transmitter
requires the use of a DRBIIItscan tool and the
proper Diagnostic Procedures manual. The DRBIIIt
scan tool can provide confirmation that the PCI data
bus is functional, and that all of the electronic mod-
ules are sending and receiving the proper messages
on the PCI data bus.
STANDARD PROCEDURE
STANDARD PROCEDURE - RKE TRANSMITTER
BATTERIES
The Remote Keyless Entry (RKE) transmitter case
snaps open and shut for battery access. To replace
the RKE transmitter batteries:(1) Using a thin coin, gently pry at the notch in
the center seam of the RKE transmitter case halves
near the key ring until the two halves unsnap.
(2) Lift the back half of the transmitter case off of
the RKE transmitter.
(3) Remove the two batteries from the RKE trans-
mitter.
(4) Replace the two batteries with new Panasonic
2016, or equivalent. Be certain that the batteries are
installed with their polarity correctly oriented.
(5) Align the two RKE transmitter case halves
with each other, and squeeze them firmly and evenly
together until they snap back into place.
STANDARD PROCEDURE - RKE TRANSMITTER
CUSTOMER PREFERENCES
AUTOMATIC (ROLLING) LOCKS
The rolling locks feature can be toggled ON/OFF
by using the DRB IIItonly.
HORN CHIRP DISABLING / ENABLING
The horn chirp can be toggled using a DRB IIItor
by using the Remote Keyless Entry (RKE) transmit-
ter.
To DISABLE (cancel) the horn chirp feature, press
and hold the transmitter LOCK button for four to ten
seconds. While pressing the LOCK button in, press
the UNLOCK button. Release both buttons.
To ENABLE the horn chirp feature, repeat the
above procedure.
OPTICAL CHIRP (FLASH) DISABLING / ENABLING
The optical chirp can be toggled using a DRB IIIt
or by using the Remote Keyless Entry (RKE) trans-
mitter.
To DISABLE (cancel) the optical chirp feature,
press and hold the transmitter LOCK button for four
to ten seconds. While pressing the LOCK button in,
press the TAILGATE RELEASE button. Release both
buttons.
To ENABLE the optical chirp feature, repeat the
above procedure.
TAIL GATE RELEASE DELAY
Press the UNLOCK button for four to ten seconds.
While pressing the UNLOCK button, press the TAIL
GATE RELEASE button. Release both buttons.
This will toggle between PRESS AND HOLD and
PRESS (no delay).
UNLOCK SEQUENCE
The unlock sequence can be toggled using a DRB
IIItor by using the Remote Keyless Entry (RKE)
transmitter.
Fig. 5 RKE Module Remove/Install
1 - SCREW (4)
2 - RKE MODULE
3 - BODY CONTROL MODULE
4 - JUNCTION BLOCK
8N - 8 POWER LOCKSKJ
REMOTE KEYLESS ENTRY MODULE (Continued)

Press and hold the transmitter UNLOCK button
for four to ten seconds. While pressing the UNLOCK
button in, press the LOCK button. Release both but-
tons.
This will toggle between Driver door first and
Unlock all doors function.
STANDARD PROCEDURE - RKE TRANSMITTER
PROGRAMING
New Remote Keyless Entry (RKE) transmitters can
be programed using the DRBIIItscan tool and the
proper Diagnostic Procedures manual. The DRBIIIt
scan tool can provide confirmation that the PCI data
bus is functional, and that all of the electronic mod-
ules are sending and receiving the proper messages
on the PCI data bus.
The following procedure can be used as long as one
functioning transmitter is available:
(1) Using the original transmitter, press the
UNLOCK button for 4 to 10 seconds.
(2) Without releasing the UNLOCK button, press
the PANIC button (within the 4 to 10 second inter-
val).
(3) Release both buttons.
(4) Press LOCK and UNLOCK simultaneously on
the original transmitter.
(5) Release both buttons.
(6) Press any button on the ORIGINAL transmit-
ter. A chime tone from the instrument cluster will
confirm the programming of the ORIGINAL trans-
mitter.
(7) On NEW transmitter, press LOCK and
UNLOCK simultaneously.
(8) Release both buttons.
(9) Press any button on the NEW transmitter. A
chime tone from the instrument cluster will confirm
the programming of the NEW transmitter.
(10) Up to four transmitters can be programed for
one vehicle.
SPECIFICATIONS - REMOTE KEYLESS ENTRY
TRANSMITTER
RANGE
Normal operation range is up to a distance of 3 to
7 meters (10 to 23 ft.) of the vehicle. Range may be
better or worse depending on the environment
around the vehicle.
TAILGATE CYLINDER LOCK
SWITCH
DESCRIPTION
The tailgate cylinder lock switch is integral to the
key lock cylinder inside the tailgate. The tailgate cyl-
inder lock switch is a normally-open momentary
switch that is hard wired directly to the Body Con-
trol Module (BCM), and closes a path to ground
through an internal resistor when the lock cylinder is
rotated to the unlock or lock position.
The tailgate cylinder lock switch cannot be
adjusted or repaired.
OPERATION
The tailgate cylinder lock switch is actuated when
the key is inserted in the lock cylinder and turned to
the unlock or lock position. The tailgate cylinder lock
switch closes a path to ground through an internal
resistor for the Body Control Module (BCM) when
the tailgate key lock cylinder is in the lock or unlock
position, and opens the ground path when the lock
cylinder is in the neutral position. The BCM reads
the switch status, then sends the proper switch sta-
tus messages to other electronic modules over the
Programmable Communications Interface (PCI) data
bus network. The tailgate cylinder lock switch unlock
status message is used by the BCM as an input for
Vehicle Theft Security System (VTSS) operation and
to tell the BCM to lock or unlock the tailgate. There
is no mechanical linkage between the tailgate key
cylinder and the latches.
DIAGNOSIS AND TESTING - TAILGATE
CYLINDER LOCK SWITCH
(1) Disconnect and isolate the battery negative
cable.
(2) Remove tailgate trim panel (Refer to 23 -
BODY/DECKLID/HATCH/LIFTGATE/TAILGATE/
TRIM PANEL - REMOVAL).
(3) Disconnect tailgate cylinder lock switch har-
ness connector.
(4) Using a ohmmeter, test for resistances as
shown in the Tailgate Cylinder Lock Switch Table.
KJPOWER LOCKS 8N - 9
REMOTE KEYLESS ENTRY TRANSMITTER (Continued)

TAILGATE CYLINDER LOCK SWITCH TABLE
SWITCH POSITION RESISTANCE
NEUTRAL 0 OHMS
LOCK (CLOCKWISE) 2 K OHMS   10 %
UNLOCK (COUNTER-
CLOCKWISE)470 OHMS   10 %
(5) If switch resistance is not correct, replace
switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the tailgate trim panel.(Refer to 23 -
BODY/DECKLID/HATCH/LIFTGATE/TAILGATE/
TRIM PANEL - REMOVAL).
(3) Remove the retainer clip from the pin on the
back of the door lock cylinder (Fig. 6).
(4) Remove the washer from the pin on the back of
the door lock cylinder.
(5) Remove the door cylinder lock switch from the
back of the lock cylinder.
INSTALLATION
(1) Position the tailgate cylinder lock switch onto
the back of the lock cylinder with the wire harness
oriented toward the bottom.
(2) Position the washer over the switch.
(3) Install the retainer clip onto the pin on the
back of the tailgate lock cylinder. Be certain that thecenter tab of the retainer is engaged in the retention
hole on the lock lever.
(4) Install the trim panel (Refer to 23 - BODY/
DECKLID/HATCH/LIFTGATE/TAILGATE/TRIM
PANEL - INSTALLATION).
(5) Connect the battery negative cable.
Fig. 6 Lock Cylinder Switch Remove/Install -Typical
1 - LEVER
2 - RETAINER
3 - LOCK CYLINDER
4 - SWITCH
5 - PLIERS
6 - OUTSIDE DOOR HANDLE
8N - 10 POWER LOCKSKJ
TAILGATE CYLINDER LOCK SWITCH (Continued)

POWER MIRRORS
TABLE OF CONTENTS
page page
POWER MIRRORS
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING - POWER
MIRRORS...........................11
POWER MIRROR SWITCH
DIAGNOSIS AND TESTING - POWER MIRROR
SWITCH............................12REMOVAL.............................13
INSTALLATION.........................13
SIDEVIEW MIRROR
REMOVAL.............................13
POWER MIRRORS
DESCRIPTION
The available power operated sideview mirrors
allow the driver to adjust both outside mirrors elec-
trically from the drivers seat by operating a switch
on the driver side front door trim panel (Fig. 1).
OPERATION
The power mirrors receive ignition current through
a fuse in the junction block, and will only operate
when the ignition switch is in the Run position.
DIAGNOSIS AND TESTING - POWER MIRRORS
WIRING VOLTAGE TEST
The following wiring test determines whether or
not voltage is continuous through the body harness
to switch.
(1) Remove the power mirror switch (Refer to 8 -
ELECTRICAL/POWER MIRRORS/POWER MIRROR
SWITCH - REMOVAL).
(2) Disconnect wire connector from back of power
mirror switch.
(3) Switch ignition to the RUN position.
(4) Connect the clip end of a 12 volt test light to
Pin 5 in the harness connector at the mirror switch.
Touch the test light probe to Pin 3.
If the test light illuminates, the wiring circuit
between the battery and switch is OK.
If the lamp does not illuminate, first check fuse 25
in the Junction Block (JB). If fuse 25 is OK, then
check for a broken wire.
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.
POWER MIRROR MOTOR TEST
If the power mirror switch is receiving proper cur-
rent and ground and mirrors do not operate, proceed
with power mirror motor test. Refer to the appropri-
ate 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 connec-
tors, splices and grounds.
Fig. 1 POWER MIRROR SWITCH
1 - DOOR TRIM PANEL
2 - DOOR LOCK SWITCH
3 - POWER MIRROR SWITCH
KJPOWER MIRRORS 8N - 11