2002 JEEP GRAND CHEROKEE Ecu

(LED) for visibility, and are also color-coded to coin-
cide with the color-coded Driver 1 and Driver 2
Remote Keyless Entry (RKE) transmitters. The
Driver 1 memory switch button and RKE transmitter
are black, and the Driver 2 memory switch button
and RKE transmitter are gray. The memory switch
Set button also has an LED that will illuminate and
flash to indicate that the memory system is in the set
mode. This LED will automatically be extinguished
when a set request has been successfully completed.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the memory switch. For diagnosis of the memory
switch, the DDM or the PCI data bus, the use of a
DRB scan tool and the proper Diagnostic Procedures
manual are recommended.
DIAGNOSIS AND TESTING - MEMORY SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the driver side front door trim panel.
Refer to the Body section for the procedure.
(3) Disconnect the memory switch wire harness
connector from the driver door module connector
receptacle.
(4) Use an ohmmeter to test the resistances of the
memory switch in each switch position. See the Mem-
ory Switch Test chart MEMORY SWITCH TEST . If
OK, refer toMemory System Diagnosis and Test-
ingin this group. If not OK, replace the faulty mem-
ory switch.
MEMORY SWITCH TEST
MEMORY
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
RANGE
(OHMS)
NEUTRAL A&D 14000   1%
MEMORY 1 A&B 4600   1%
MEMORY 2 A&B 1700   1%
SET A&B 300   1%
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the driver side
front door. Refer toFront Door Trim Panelin Body
for the procedure.
(3) Disconnect the memory switch wire harness
connector from the driver door module connector
receptacle.
(4) Remove the two screws that secure the memory
switch to the back of the driver side front door trim
panel.(5) Remove the memory switch from the back of
the driver side front door trim panel.
INSTALLATION
(1) Position the memory switch onto the back of
the driver side front door trim panel.
(2) Install and tighten the two screws that secure
the memory switch to the back of the driver side
front door trim panel. Tighten the screws to 2.2 N´m
(20 in. lbs.).
(3) Reconnect the memory switch wire harness
connector to the driver door module connector recep-
tacle.
(4) Install the trim panel onto the driver side front
door. Refer toFront Door Trim Panelin Body for
the procedure.
(5) Reconnect the battery negative cable.
PASSENGER SEAT SWITCH
DESCRIPTION
Two different power seat switches are used on this
vehicle, depending upon the optional power seat sys-
tem installed in the vehicle. The six-way power seats
are each equipped with a switch featuring three
switch control knobs ganged together on the outboard
seat cushion side shield (Fig. 13). The ten-way power
seats are each equipped with a switch featuring two
knobs ganged together on the outboard seat cushion
side shield (Fig. 14).
The switch units for both power seat types are
secured to the back of the seat cushion side shield
with two screws. However, the control knobs for the
six-way power seat switch unit remain installed dur-
Fig. 13 Six-Way Power Seat Switches - Typical
1 - OUTBOARD SEAT CUSHION SIDE SHIELD
2 - POWER SEAT TRACK SWITCHES
3 - MECHANICAL SEAT BACK RECLINER LEVER
WJPOWER SEAT SYSTEM 8N - 27
MEMORY SET SWITCH (Continued)

ing switch unit removal and installation, while both
knobs for the ten-way power seat switch unit must
be removed.
The individual switches in both power seat switch
units cannot be repaired. If one switch is damaged or
faulty, the entire power seat switch unit must be
replaced.
OPERATION
The power seat tracks of both the six-way and the
ten-way power seat systems can be adjusted in six
different ways using the power seat switches. The
ten-way system has the additional power seat
recliner switch integral to the power seat switch and
also has a separate, stand-alone switch to control the
power lumbar adjuster. See the owner's manual in
the vehicle glove box for more information on the
power seat switch functions and the seat adjusting
procedures.
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them fromoverload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS AND TESTING - PASSENGER SEAT
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the out-
board seat cushion side shield. Refer to the procedure
in this section of the manual.
(3) Use an ohmmeter to test the continuity of the
power seat switch in each switch position. See the
Power Seat Switch Continuity chart (Fig. 15) or (Fig.
16). If OK, refer toDiagnosis and Testing Power
Seat TrackorDiagnosis and Testing Power Seat
Reclinerin this section. If not OK, replace the
faulty power seat switch.
Fig. 14 Ten-Way Power Seat Switches - Typical
1 - OUTBOARD CUSHION SIDE SHIELD
2 - POWER SEAT RECLINER SWITCH
3 - POWER SEAT TRACK SWITCH
4 - POWER LUMBAR SWITCH
Fig. 15 Rear Of Six-Way Power Seat Switch
SIX-WAY POWER SEAT SWITCH TEST
LEFT SWITCH
POSITIONRIGHT
SWITCH
POSITIONCONTINUITY
BETWEEN
OFF OFFB-N, B-J, B-M,
B-E, B-L, B-K
VERTICAL UPVERTICAL
DOWNA-J, A-N, B-M,
B-E
VERTICAL
DOWNVERTICAL UPA-E, A-M, B-N,
B-J
HORIZONTAL
FORWARDHORIZONTAL
REARWARDA-K, B-L
FRONT TILT
UPFRONT TILT
DOWNA-J, B-E
FRONT TILT
DOWNFRONT TILT
UPA-E, B-J
REAR TILT UPREAR TILT
DOWNA-N, B-M
REAR TILT
DOWNREAR TILT UP A-M, B-N
8N - 28 POWER SEAT SYSTEMWJ
PASSENGER SEAT SWITCH (Continued)

SWITCH
POSITIONCONTINUITY BETWEEN PINS
LEFT SEAT RIGHT SEAT
OFF PIN1to2 PIN1to2
PIN1to3 PIN1to3
PIN1to4 PIN1to4
PIN1to6 PIN1to6
PIN1to7 PIN1to7
PIN1to8 PIN1to8
PIN1to9 PIN1to9
PIN1to10 PIN1to10
FRONT RISER
UPPIN1to10 PIN1to7
PIN5to7 PIN5to10
FRONT RISER
DOWNPIN1to7 PIN1to10
PIN5to10 PIN5to7
CENTER
SWITCH
FORWARDPIN1to3 PIN1to3
PIN5to6 PIN5to6
CENTER
SWITCH
REARWARDPIN1to6 PIN1to6
PIN3to5 PIN3to5
REAR RISER
UPPIN1to9 PIN1to8
PIN5to8 PIN5to9
REAR RISER
DOWNPIN1to8 PIN1to9
PIN5to9 PIN5to8
RECLINER UP PIN 1 to 4 PIN 1 to 4
PIN2to5 PIN2to5
RECLINER
DOWNPIN1to2 PIN1to2
PIN4to5 PIN4to5
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) On models with the ten-way power seat system
only, using a push pin remover or another suitable
wide flat-bladed tool, gently pry the power seat and
power recliner switch knobs off of the switch stems
(Fig. 17).
(3) Remove the three screws that secure the out-
board seat cushion side shield to the seat cushion
frame.
(4) Pull the outboard seat cushion side shield away
from the seat cushion frame far enough to access the
power seat switch wire harness connector.
(5) Disconnect the power seat wire harness connec-
tor from the power seat switch connector receptacle.
(6) Remove the two screws that secure the power
seat switch to the inside of the outboard seat cushion
side shield (Fig. 18) or (Fig. 19).
(7) Remove the power seat switch from the out-
board seat cushion side shield.
INSTALLATION
(1) Position the power seat switch onto the out-
board seat cushion side shield.
(2) Install and tighten the two screws that secure
the power seat switch to the inside of the outboard
seat cushion side shield. Tighten the screws to 1.5
N´m (14 in. lbs.).
(3) Reconnect the power seat wire harness connec-
tor to the power seat switch connector receptacle.
Fig. 16 Ten-Way Power Seat
Switch Connector Receptacle
Fig. 17 Removing Switch Control Knobs - Typical
WJPOWER SEAT SYSTEM 8N - 29
PASSENGER SEAT SWITCH (Continued)

(4) Position the outboard seat cushion side shield
onto the seat cushion frame
(5) Install and tighten the three screws that secure
the outboard seat cushion side shield to the seat
cushion frame. Tighten the screws to 1.5 N´m (14 in.
lbs.).
(6) On models with the ten-way power seat system
only, position the power seat and power recliner
switch knobs onto the switch stems and push on
them firmly and evenly until they snap into place.
(7) Reconnect the battery negative cable.
RECLINER MOTOR
DESCRIPTION
The ten-way power seat option includes an electri-
cally operated seat back recliner mechanism. The
only visible evidence of this option is the separate
power seat recliner switch control knob that is
located on the outboard seat cushion side shield, just
behind the other power seat switch control knob. The
power seat recliner switch is integral to the ten-way
power seat switch unit, but is actuated with a sepa-
rate switch knob.
The power seat recliner unit is mounted in the
place of a seat hinge on the outboard side of the seat
(Fig. 20). The upper hinge plate of the power seat
recliner mechanism is secured with two screws to the
seat back frame and is concealed beneath the seat
back trim cover and padding. The lower hinge plate
and the motor and drive unit of the power seat
recliner mechanism is secured with two screws to the
seat cushion frame, and is concealed by the outboard
seat cushion side shield.
The power seat recliner cannot be repaired. If the
unit is faulty or damaged, it must be replaced. Refer
toBucket Seat Reclinerin Body for the service
procedure.
OPERATION
The power seat recliner includes a reversible elec-
tric motor that is secured to the lower hinge plate of
the recliner unit. The motor is connected to a gearbox
that moves the upper hinge plate of the power seat
recliner through a screw-type drive unit. The driver
side power seat recliner motor used on models
equipped with the optional memory system also has
a position potentiometer integral to the motor assem-
bly, which electronically monitors the motor position.
DIAGNOSIS AND TESTING - RECLINER MOTOR
Actuate the power seat recliner switch to move the
power seat recliner adjuster in each direction. The
power seat recliner adjuster should move in both
directions. If the power seat recliner adjuster fails to
operate in only one direction, move the adjuster a
short distance in the opposite direction and test
again to be certain that the adjuster is not at its
travel limit. If the power seat recliner adjuster still
fails to operate in only one direction, refer toPower
Seat Switch Diagnosis and Testingin this group.
If the power recliner adjuster fails to operate in
either direction, perform the following tests. For com-
plete circuit diagrams, refer toWiring Diagrams.
(1) Check the power seat circuit breaker in the
junction block. If OK, go to Step 2. If not OK, replace
the faulty power seat circuit breaker.
Fig. 18 Six-Way Power Seat Switches Remove/
Install
1 - SEAT SIDE SHIELD
2 - POWER SEAT SWITCH
3 - SCREWS
Fig. 19 Ten-Way Power Seat Switches Remove/
Install
1 - POWER SEAT SWITCH
2 - SCREWS (2)
3 - POWER LUMBAR SWITCH
4 - SEAT CUSHION SIDE SHIELD
5 - WIRE HARNESS CONNECTOR
8N - 30 POWER SEAT SYSTEMWJ
PASSENGER SEAT SWITCH (Continued)

(2) Check for battery voltage at the power seat cir-
cuit breaker in the junction block. If OK, go to Step
3. If not OK, repair the open fused B(+) circuit to the
fuse in the Power Distribution Center as required.
(3) Remove the outboard seat cushion side shield
from the seat. Disconnect the seat wire harness con-
nector from the power seat switch connector recepta-
cle. Check for battery voltage at the fused B(+)
circuit cavity of the power seat wire harness connec-
tor for the power seat switch. If OK, go to Step 4. If
not OK, repair the open fused B(+) circuit to the
power seat circuit breaker in the junction block as
required.(4) Check for continuity between the ground cir-
cuit cavity of the power seat wire harness connector
for the power seat switch and a good ground. There
should be continuity. If OK, go to Step 5. If not OK,
repair the open ground circuit to ground as required.
(5) Test the power seat switch. Refer toPower
Seat Switch Diagnosis and Testingin this group.
If the switch tests OK, test the circuits of the power
seat wire harness between the power seat recliner
adjuster motor and the power seat switch for shorts
or opens. If the circuits check OK, replace the faulty
power seat recliner unit. If the circuits are not OK,
repair the power seat wire harness as required.
POWER SEAT TRACK
DESCRIPTION
Both the six-way and the ten-way power seat
options include a single electrically operated power
seat track unit located under each front bucket seat
(Fig. 21). The power seat track unit replaces the
standard equipment manual seat tracks. The lower
half of the power seat track is secured at the front
with two screws to the floor panel seat cross member,
and at the rear with two screws to the floor panel.
Four nuts secure the bottom of the seat cushion
frame to four studs on the upper half of the power
seat track unit.
The power seat track unit cannot be repaired, and is
serviced only as a complete unit. If any component in
this unit is faulty or damaged, the entire power seat
track unit must be replaced. Refer toBucket Seat
Track Adjuster
in Body for the service procedure.
Fig. 20 Power Seat Recliner and Track - Typical
1 - SEAT BACK FRAME
2 - SEAT CUSHION PAD
3 - POWER RECLINER
4 - SEAT CUSHION FRAME
5 - SHIELD
6 - POWER SEAT TRACK ADJUSTER
Fig. 21 Power Seat Track - Typical
1 - DRIVE UNITS
2 - LOWER SEAT TRACKS
3 - POWER SEAT MOTORS
4 - SEAT CUSHION FRAME
WJPOWER SEAT SYSTEM 8N - 31
RECLINER MOTOR (Continued)

OPERATION
The power seat track unit includes three reversible
electric motors that are secured to the upper half of
the track unit. Each motor moves the seat adjuster
through a combination of worm-drive gearboxes and
screw-type drive units. Each of the three driver side
power seat track motors used on models equipped
with the optional memory system also has a position
potentiometer integral to the motor assembly, which
electronically monitors the motor position.
The front and rear of the seat are operated by two
separate vertical adjustment motors. These motors
can be operated independently of each other, tilting
the entire seat assembly forward or rearward; or,
they can be operated in unison by selecting the
proper power seat switch functions, which will raise
or lower the entire seat assembly. The third motor is
the horizontal adjustment motor, which moves the
seat track in the forward and rearward directions.
DIAGNOSIS AND TESTING - POWER SEAT
TRACK
Following are tests that will help to diagnose the
hard wired components and circuits of the power seat
system. However, if the vehicle is also equipped with
the optional memory system, these tests may not
prove conclusive in the diagnosis of the driver side
power seat. In order to obtain conclusive testing of
the driver side power seat with the memory system
option, the Programmable Communications Interface
(PCI) data bus network and all of the electronic mod-
ules that provide inputs to, or receive outputs from
the memory system components must be checked.
The most reliable, efficient, and accurate means to
diagnose the driver side power seat with the memory
system option requires the use of a DRBtscan tool
and the proper Diagnostic Procedures manual. The
DRBtscan tool can provide confirmation that the
PCI data bus is functional, that all of the electronic
modules are sending and receiving the proper mes-
sages on the PCI data bus, and that the memory sys-
tem is receiving the proper hard wired inputs and
relaying the proper hard wired outputs to perform its
driver side power seat functions.Actuate the power seat switch to move all three
power seat track adjusters in each direction. The
power seat track adjusters should move in each of
the selected directions. If a power seat track adjuster
fails to operate in only one direction, move the
adjuster a short distance in the opposite direction
and test again to be certain that the adjuster is not
at its travel limit. If the power seat track adjuster
still fails to operate in only one direction, refer to
Power Seat Switch Diagnosis and Testingin this
group. If the power seat track adjuster fails to oper-
ate in more than one direction, perform the following
tests. For complete circuit diagrams, refer toWiring
Diagrams.
(1) Check the power seat circuit breaker in the
junction block. If OK, go to Step 2. If not OK, replace
the faulty power seat circuit breaker.
(2) Check for battery voltage at the power seat cir-
cuit breaker in the junction block. If OK, go to Step
3. If not OK, repair the open fused B(+) circuit to the
fuse in the Power Distribution Center as required.
(3) Remove the outboard seat cushion side shield
from the seat. Disconnect the seat wire harness con-
nector from the power seat switch connector recepta-
cle. Check for battery voltage at the fused B(+)
circuit cavity of the power seat wire harness connec-
tor for the power seat switch. If OK, go to Step 4. If
not OK, repair the open fused B(+) circuit to the
power seat circuit breaker in the junction block as
required.
(4) Check for continuity between the ground cir-
cuit cavity of the power seat wire harness connector
for the power seat switch and a good ground. There
should be continuity. If OK, go to Step 5. If not OK,
repair the open ground circuit to ground as required.
(5) Test the power seat switch. Refer toPower
Seat Switch Diagnosis and Testingin this group.
If the switch tests OK, test the circuits of the power
seat wire harness between the inoperative power seat
track adjuster motor and the power seat switch for
shorts or opens. If the circuits check OK, replace the
faulty power seat track unit. If the circuits are not
OK, repair the power seat wire harness as required.
8N - 32 POWER SEAT SYSTEMWJ
POWER SEAT TRACK (Continued)

INSTALLATION
(1) Position the power window switch to the rear
door trim panel switch receptacle.
(2) Press firmly and evenly on the back of the
power window switch until it snaps into rear door
trim panel switch receptacle.
(3) Install the trim panel onto the rear door. (Refer
to 23 - BODY/DOORS - REAR/TRIM PANEL -
INSTALLATION) for the procedures.
(4) Reconnect the battery negative cable.
WINDOW MOTOR
DESCRIPTION
Power operated front and rear door windows are
standard equipment on this model. Each door has a
permanent magnet reversible electric motor with an
integral right angle gearbox mechanism that oper-
ates the window regulator. In addition, each power
window motor is equipped with an integral self-reset-
ting circuit breaker to protect the motor from over-
loads.
The power window motor gearbox housing is
secured to the window regulator drum housing with
screws. The window regulators used in all four doors
are single vertical post cable-and-drum type. A
molded plastic slider guided by the post is driven by
the regulator cables. The slider raises and lowers the
window glass through a steel lift plate attachment.
Front and rear glass channels within each door guide
and stabilize each end of the glass.
The power window motor and gearbox assembly
cannot be repaired and, if faulty or damaged, the
entire power window motor and gearbox unit must be
replaced. The window regulators are available for
service. (Refer to 23 - BODY/DOOR - FRONT/WIN-
DOW REGULATOR - REMOVAL) or (Refer to 23 -
BODY/DOORS - REAR/WINDOW REGULATOR -
REMOVAL) for the regulator service procedures.
OPERATION
A positive and negative battery connection to the
two motor terminals will cause the power window
motor to rotate in one direction. Reversing the cur-
rent through these same two connections will cause
the motor to rotate in the opposite direction.
When the power window motor operates, it rotates
the regulator cable drum through its gearbox. The
window regulator cable drum is connected through
two cables to the plastic slider on the vertical post.
As the cable drum rotates, it lets cable out on one
side of the drum, and takes cable in on the other side
of the drum. The changes in cable length move the
slider up or down the vertical post, raising or lower-
ing the window glass.If the window regulator or window glass bind,
encounter obstructions, or reach their travel limits it
overloads the power window motor. The overloading
condition causes the power window motor self-reset-
ting circuit breaker to open, which stops the motor
from running.
DIAGNOSIS AND TESTING - WINDOW MOTOR
Before you proceed with this diagnosis, confirm
proper switch operation. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DRIVER
DOOR MODULE - OPERATION) or (Refer to 8 -
ELECTRICAL/POWER WINDOWS/POWER WIN-
DOW SWITCH - OPERATION). For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
(1) Remove the trim panel from the door with the
inoperative power window. (Refer to 23 - BODY/
DOOR - FRONT/TRIM PANEL - REMOVAL) or
(Refer to 23 - BODY/DOORS - REAR/TRIM PANEL -
REMOVAL) for the procedures.
(2) Disconnect the door wire harness connector
from the power window motor wire harness connec-
tor. Apply battery current to one cavity of the power
window motor wire harness connector, and apply
ground to the other cavity of the connector. The
power window motor should operate in one direction.
Remember, if the window is in the full up or full
down position, the motor will not operate in that
direction by design. If OK, go to Step 3. If not OK,
replace the faulty power window motor.
(3) Reverse the battery and ground connections to
the two cavities of the power window motor wire har-
ness connector. The power window motor should now
operate in the other direction. Remember, if the win-
dow is in the full up or full down position, the motor
will not operate in that direction by design. If OK, go
to Step 4. If not OK, replace the faulty power window
motor.
(4) If the power window motor operates in both
directions, check the operation of the window glass
and regulator mechanism through its complete up
and down travel. There should be no binding or stick-
ing of the window glass or regulator mechanism
through the entire travel range. If not OK, (Refer to
23 - BODY/DOOR - FRONT/WINDOW REGULATOR
- REMOVAL) or (Refer to 23 - BODY/DOORS -
REAR/WINDOW REGULATOR - REMOVAL) to
check for proper installation or damage of the win-
dow glass mounting and operating hardware.
8N - 38 POWER WINDOWSWJ
POWER WINDOW SWITCH (Continued)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the window regulator from the door.
(Refer to 23 - BODY/DOOR - FRONT/WINDOW
REGULATOR - REMOVAL) or (Refer to 23 - BODY/
DOORS - REAR/WINDOW REGULATOR -
REMOVAL) for the procedures.
(3) Place the window regulator on a suitable work
surface and remove the screws that secure the power
window motor to the window regulator.
(4) Remove the power window motor from the win-
dow regulator.
INSTALLATION
(1) Position the power window motor onto the win-
dow regulator.
(2) Install and tighten the screws that secure the
power window motor to the window regulator.
Tighten the screws to 9 N´m (80 in. lbs.).
(3) Install the window regulator onto the door.
(Refer to 23 - BODY/DOOR - FRONT/WINDOW
REGULATOR - INSTALLATION) or(Refer to 23 -
BODY/DOORS - REAR/WINDOW REGULATOR -
INSTALLATION) for the procedures.
(4) Reconnect the battery negative cable.
WJPOWER WINDOWS 8N - 39
WINDOW MOTOR (Continued)