tow JEEP GRAND CHEROKEE 2002 WJ / 2.G Service Manual

NOTE: If the vehicle is equipped with the Tire Pres-
sure Monitoring (TPM) System, and the overhead
console electronics module is removed or replaced,
the TPM system will need to be retrained. Refer to
the Tires/Wheels section of this manual for the pro-
cedure.
UNIVERSAL TRANSMITTER
DESCRIPTION
The Grand Cherokee Limited model has a Univer-
sal Garage Door Opener (UGDO) transceiver as stan-
dard factory-installed equipment. The UGDO is
optional on Laredo models. The UGDO transceiver is
integral to the Electronic Vehicle Information Center
(EVIC), which is located in the overhead console. The
only visible component of the UGDO are the three
transmitter push buttons centered between the four
EVIC push buttons located just rearward of the
EVIC display screen in the overhead console. The
three UGDO transmitter push buttons are identified
with one, two or three dots so that they be easily
identified by sight.
Each of the three UGDO transmitter push buttons
controls an independent radio transmitter channel.
Each of these three channels can be trained to trans-
mit a different radio frequency signal for the remoteoperation of garage door openers, motorized gate
openers, home or office lighting, security systems or
just about any other device that can be equipped
with a radio receiver in the 288 to 410 MegaHertz
(MHz) frequency range for remote operation. The
UGDO is capable of operating systems using either
rolling code or non-rolling code technology.
The EVIC 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 UGDO. The EVIC messages are:
²Cleared Channels- Indicates that all of the
transmitter codes stored in the UGDO have been suc-
cessfully cleared.
²Training- Indicates that the UGDO is in its
transmitter learning mode.
²Trained- Indicates that the UGDO has success-
fully acquired a new transmitter code.
²Transmit- Indicates that a trained UGDO
transmitter button has been depressed and that the
UGDO is transmitting.
The UGDO cannot be repaired, and is available for
service only as a unit with the EVIC module. This
unit includes the push button switches and the plas-
tic module. If any of these components are faulty or
damaged, the complete EVIC 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
Electronic Vehicle Information Center (EVIC) is oper-
ating normally, see the owner's manual in the vehicle
glove box for instructions on training the Transmit-
ter. Retrain the Transmitter with a known good
transmitter as instructed in the owner's manual and
test the Transmitter operation again. If the unit is
still inoperative, replace the faulty Transmitter and
EVIC module as a unit. If both the Transmitter and
the EVIC module are inoperative, refer toElec-
tronic Vehicle Information Center Diagnosis
and Testingin this group for further diagnosis. For
complete circuit diagrams, refer toWiring Dia-
grams.
Fig. 5 Top of Overhead Console
1 - OVERHEAD CONSOLE HOUSING
2 - EVIC MODULE
3 - ILLUMINATION LAMPS
4 - SCREWS (4)
WJMESSAGE SYSTEMS 8M - 11
ELECTRONIC VEHICLE INFO CENTER (Continued)

DIAGNOSIS AND TESTING - DRIVER 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. 3) or (Fig.
4). 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.
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
Fig. 3 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 UP A-E, B-J
REAR TILT UPREAR TILT
DOWNA-N, B-M
REAR TILT
DOWNREAR TILT UP A-M, B-N
Fig. 4 Ten-Way Power Seat
Switch Connector Receptacle
8N - 22 POWER SEAT SYSTEMWJ
DRIVER SEAT SWITCH (Continued)

LUMBAR CONTROL SWITCH
DESCRIPTION
The ten-way power seat option includes an electri-
cally operated lumbar support mechanism. A single
two-way momentary power lumbar switch is located
on the outboard seat cushion side shield of each front
seat, just forward of the other power seat switches
(Fig. 8). The power lumbar switch is secured to the
back of the seat cushion side shield with two screws,
and the switch paddle protrudes through a hole to
the outside of the shield. The switch paddle is located
in a shallow depression molded into the outer surface
of the seat cushion side shield that helps to shroud it
from unintentional actuation when entering or leav-
ing the vehicle.
The power lumbar switches cannot be adjusted or
repaired and, if faulty or damaged, they must be
replaced.
OPERATION
When the power lumbar switch paddle is actuated,
a battery feed and a ground path are applied through
the switch contacts to the power lumbar adjuster
motor. The motor operates to move the lumbar
adjuster 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 motor to run in the
opposite direction.
The power lumbar switch should not be held
applied in either direction after the adjuster hasreached its travel limit. The power lumbar adjuster
motor contains a self-resetting circuit breaker to pro-
tect it from overload. However, consecutive or fre-
quent resetting of the circuit breaker must not be
allowed to continue, or the motor may be damaged.
DIAGNOSIS AND TESTING - POWER LUMBAR
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power lumbar 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 lumbar switch in each switch position. See the
Power Lumbar Switch Continuity chart (Fig. 9). If
OK, refer toPower Lumbar Adjuster Diagnosis
and Testingin this group. If not OK, replace the
faulty power lumbar switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Fig. 8 Ten-Way Power Seat Switches
1 - OUTBOARD CUSHION SIDE SHIELD
2 - POWER SEAT RECLINER SWITCH
3 - POWER SEAT TRACK SWITCH
4 - POWER LUMBAR SWITCH
Fig. 9 Power Lumbar Switch
POWER LUMBAR SWITCH
LEFT SWITCH
POSITIONRIGHT
SWITCH
POSITIONCONTINUITY
BETWEEN
Off Off 2-4, 3-5
Forward Rearward 3-5, 4-6
Rearward Forward 2-4, 3-6
8N - 24 POWER SEAT SYSTEMWJ

OPERATION
The power lumbar adjuster mechanism includes a
reversible electric motor that is secured to the
inboard side of the seat back panel and is connected
to a worm-drive gearbox. The motor and gearbox
operate the lumbar adjuster mechanism in the center
of the seat back by extending and retracting a cable
that actuates a lever. The action of this lever com-
presses or relaxes a grid of flexible slats. The more
this grid is compressed, the more the slats bow out-
ward against the center of the seat back padding,
providing additional lumbar support.
DIAGNOSIS AND TESTING - POWER LUMBAR
ADJUSTER
Actuate the power lumbar switch to move the
power lumbar adjuster in each direction. The power
lumbar adjuster should move in both directions. It
should be noted that the power lumber adjuster nor-
mally operates very quietly and exhibits little visible
movement. If the power lumbar adjuster fails to oper-
ate 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 lumbar adjuster still fails to operate in
only one direction, refer toDiagnosis and Testing
Power Lumbar Switchin this group. If the power
lumbar adjuster fails to operate in either direction,
perform the following tests. For complete circuit dia-
grams, 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 lumbar switch connector
receptacle. Check for battery voltage at the fused
B(+) circuit cavity of the power seat wire harness
connector for the power lumbar 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 lumbar 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 lumbar switch. Refer toDiag-
nosis and Testing Power Lumbar Switchin this
group. If the switch tests OK, test the circuits of the
power seat wire harness between the power lumbaradjuster motor and the power lumbar switch for
shorts or opens. If the circuits check OK, replace the
faulty seat back frame assembly. If the circuits are
not OK, repair the power seat wire harness as
required.
MEMORY SET SWITCH
DESCRIPTION
Vehicles equipped with the memory system have a
memory switch mounted to the driver side front door
trim panel (Fig. 12). This switch is used to set and
recall all of the memory system settings for up to two
drivers. The memory switch is a resistor multiplexed
unit that is hard wired to the Driver Door Module
(DDM), which is also located on the driver side front
door trim panel. The DDM sends out the memory
system set and recall requests to the other electronic
modules over the Programmable Communications
Interface (PCI) data bus.
The memory switch cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced. For
complete circuit diagrams, refer toWiring Diagrams
.
OPERATION
The memory switch has three momentary switch
buttons labeled Set, 1 and 2. The Driver 1 and Driver
2 buttons are back-lit with Light-Emitting Diodes
Fig. 12 WJ/WG MEMORY SELECT/SET SWITCH
1 - DRIVER TRIM PANEL
2 - MEMORY SWITCH
8N - 26 POWER SEAT SYSTEMWJ
LUMBAR MOTOR (Continued)

(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)

(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)

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)

(4) Check to be certain that nobody is in the vehi-
cle, then reconnect the battery negative cable.
(5) Using the DRBIIIt, read and record the active
(current) Diagnostic Trouble Code (DTC) data.
(6) Next, use the DRBIIItto read and record any
stored (historical) DTC data.
(7) If any DTC is found in Step 5 or Step 6, refer
to the appropriate diagnostic information.
(8) Use the DRBIIItto erase the stored DTC data.
If any problems remain, the stored DTC data will not
erase. Refer to the appropriate diagnostic informa-
tion to diagnose any stored DTC that will not erase.
If the stored DTC information is successfully erased,
go to Step 9.
(9) Turn the ignition switch to the Off position for
about fifteen seconds, and then back to the On posi-
tion. Observe the airbag indicator in the instrument
cluster. It should light for six to eight seconds, and
then go out. This indicates that the supplemental
restraint system is functioning normally and that the
repairs are complete. If the airbag indicator fails to
light, or lights and stays on, there is still an active
supplemental restraint system fault or malfunction.
Refer to the appropriate diagnostic information to
diagnose the problem.
AIRBAG CONTROL MODULE
DESCRIPTION
The Airbag Control Module (ACM) is also some-
times referred to as the Occupant Restraint Control-
ler (ORC) (Fig. 6). The ACM is concealed underneath
the center floor console, where it is secured by four
screws to a stamped steel mounting bracket welded
onto the top of the floor panel transmission tunnel
just forward of the park brake mechanism in the pas-
senger compartment of the vehicle.
Concealed within a hollow in the center of the die
cast aluminum ACM housing is the electronic cir-
cuitry of the ACM which includes a microprocessor,
an electronic impact sensor, an electronic safing sen-
sor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ACM housing with four screws to enclose and protect
the internal electronic circuitry and components. A
printed label on the top of the ACM housing provides
a visual verification of the proper orientation of the
unit, and should always be pointed toward the front
of the vehicle.
Two molded plastic electrical connector receptacles
exit the forward side of the ACM housing. These two
receptacles connect the ACM to the vehicle electrical
system through a dedicated take out and connector of
the instrument panel wire harness, and a dedicated
take out and connector of the airbag overlay wire
harness. For vehicles equipped with the optional side
curtain airbags, both ACM connector receptacles are
black in color and the ACM contains a second bi-di-
rectional safing sensor for the side airbags. For vehi-
cles not equipped with the optional side curtain
airbags, the ACM connector receptacles are both
gray.
The impact sensor and safing sensor internal to
the ACM are calibrated for the specific vehicle, and
are only serviced as a unit with the ACM. The ACM
cannot be repaired or adjusted and, if damaged or
faulty, it must be replaced.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the supplemental restraint system
logic circuits and controls all of the supplemental
restraint system components. The ACM uses
On-Board Diagnostics (OBD) and can communicate
with other electronic modules in the vehicle as well
as with the DRBIIItscan tool using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used for
control of the airbag indicator in the ElectroMechani-
cal Instrument Cluster (EMIC) and for supplemental
restraint system diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).
Fig. 6 Airbag Control Module
1 - AIRBAG CONTROL MODULE
2 - ORIENTATION ARROW
3 - LABEL
4 - MOUNTING HOLES (4)
5 - CONNECTOR RECEPTACLE (2)
WJRESTRAINTS 8O - 9
RESTRAINTS (Continued)

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, FRONT IMPACT SENSOR,
SIDE IMPACT SENSOR, SIDE CURTAIN AIRBAG, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
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.
WARNING: THE AIRBAG CONTROL MODULE CON-
TAINS THE IMPACT SENSOR, WHICH ENABLES
THE SYSTEM TO DEPLOY THE SUPPLEMENTAL
RESTRAINTS. NEVER STRIKE OR DROP THE AIR-
BAG CONTROL MODULE, AS IT CAN DAMAGE THE
IMPACT SENSOR OR AFFECT ITS CALIBRATION. IF
AN AIRBAG CONTROL MODULE IS ACCIDENTALLY
DROPPED DURING SERVICE, THE MODULE MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER SUPPLEMENTAL RESTRAINT DEPLOY-
MENT AND POSSIBLE OCCUPANT INJURIES.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the center console from the top of the
floor panel transmission tunnel. (Refer to 23 - BODY/
INTERIOR/FLOOR CONSOLE - REMOVAL).
(3) Remove the two nuts that secure the center
console bracket to the studs on the floor panel trans-
mission tunnel just forward of the Airbag Control
Module (ACM) (Fig. 7).
(4) Remove the center console bracket from the
two studs on the floor panel transmission tunnel.
(5) Disconnect the airbag overlay wire harness
connector for the ACM from the ACM connector
receptacle (Fig. 8). To disconnect the airbag overlay
wire harness connector from the ACM:
(a) Slide the red Connector Position Assurance
(CPA) lock on the top of the connector toward the
front of the vehicle.
(b) Depress the forward edge of the CPA lock to
release the connector latch tab and pull the connec-
tor straight away from the ACM connector recepta-
cle.(6) Disconnect the instrument panel wire harness
connector for the ACM from the ACM connector
receptacle.
Fig. 7 Center Console Bracket Remove/Install
1 - SHIFTER
2 - NUT (2)
3 - BRACKET
4 - PARK BRAKE LEVER
5 - AIRBAG CONTROL MODULE
6 - FLOOR PANEL TRANSMISSION TUNNEL
7 - INSTRUMENT PANEL WIRE HARNESS
Fig. 8 Airbag Control Module Connector
1 - INSTRUMENT PANEL WIRE HARNESS CONNECTOR
2 - LATCH TAB
3 - CPA LOCK
4 - AIRBAG OVERLAY WIRE HARNESS CONNECTOR
5 - AIRBAG CONTROL MODULE
WJRESTRAINTS 8O - 11
AIRBAG CONTROL MODULE (Continued)