ered. This defeats the day-detect logic. If OK, go to
Step 8. If not OK, replace the faulty mirror unit.
(8) With the mirror darkened, place the transmis-
sion gear selector lever in the Reverse position. The
automatic day/night mirror should return to its nor-
mal reflectance. If not OK, replace the faulty mirror
unit.
Bench testing both mirrors can be done, of care is
exercised. For an inside mirror, the pin closest to he
mount is 12V (+), the next is 12V (-). The third is
reverse override. The fourth is outside mirror (+),
and the fifth is outside mirror (-).Do not apply 12
volts to the fourth and fifth pins.With 12 volts
on pins 1 and 2, the mirror can be tested by blocking
the rear sensor and shining a light into the forward
sensor. For an outside mirror, there is a 2±pin con-
nector. Applying 1.2 volts will cause the mirror to
dim. If the mirror does not dim, the entire glass
assembly can be replaced just as it is when the glass
is broken.
WARNING: Do not apply 12 volts to the outside mir-
ror. Damage to the mirror will result.
POWER FOLDAWAY MIRROR
SWITCH - EXPORT
DESCRIPTION
These vehicles may be equipped with Power Fold-
away Mirrors. This feature allows both the driver
and passenger side view mirrors to fold inward
(retract) on demand. The vehicle has an additional
switch located on the steering column that controls
the folding function of the mirror assembly (Fig. 2).
The fold-away side view mirror is attached to the
vehicle's door in the same manner as mirrors without
the fold-away option. The fold-away mirrors unique
option is the internal motor which allows the mirrors
to fold inward on demand. The fold-away mirror
motor is not serviceable separately and if a motor is
found to be faulty the entire side view mirror must
be replaced.
OPERATION
When the mirror retract switch is depressed, both
of the side view mirrors will fold inward, Thus mak-
ing the overall width of the vehicle the smallest pos-
sible. This can be helpful were parking space is a
absolute minimum.
When the driver's door is opened, only the driver's
door mirror will unfold. If the passenger door is
opened, both mirrors will unfold.
The power fold away mirror system consists of the
following components: mirror switch, side view mir-ror, relay, wires and fuse. 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.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the upper and lower steering column
shroud (Refer to 19 - STEERING/COLUMN/LOWER
SHROUD - REMOVAL).
(3) Disconnect electrical harness connector.
(4) Remove switch from steering column shroud
(Fig. 3).
Fig. 2 POWER FOLDAWAY MIRROR SWITCH
1 - POWER FOLDAWAY MIRROR SWITCH
2 - STEERING COLUMN
Fig. 3 POWER FOLDING MIRROR SWITCH
1 - STEERING COLUMN SHROUD
2 - POWER FOLDAWAY SWITCH
8N - 48 POWER MIRRORSRS
AUTOMATIC DAY / NIGHT MIRROR (Continued)
INSTALLATION
(1) Install switch to steering column shroud.
(2) Connect wire harness connector.
(3) Install the upper and lower steering column
shroud (Refer to 19 - STEERING/COLUMN/LOWER
SHROUD - INSTALLATION).
(4) Connect the battery negative cable.
REMOTE SWITCH
DIAGNOSIS AND TESTING - REMOTE SWITCH
(1) Remove power mirror switch. (Refer to 8 -
ELECTRICAL/POWER MIRRORS/POWER MIRROR
SWITCH - REMOVAL).
(2) Disconnect wiring harness at switch connector.
(3) Using a ohmmeter, test for continuity between
the terminals of the switch (Fig. 4).
MIRROR SWITCH TEST
MIRROR SELECT SWITCH IN ªLEFTº
POSITION
Move
ButtonContinuity Between
UP PIN 9 - PIN 12,
PIN 6 - PIN 11,
PIN 9 - PIN 13
LEFT PIN 9 - PIN 7,
PIN 6 - PIN 11,
PIN 9 - PIN 8
DOWN PIN 9 - PIN 6,
PIN 12 - PIN 11,
PIN 13 - PIN 11
RIGHT PIN 9 - PIN 6,
PIN 7 - PIN 11,
PIN 8 - PIN 11
MIRROR SELECT SWITCH IN ªRIGHTº
POSITION
Move
ButtonContinuity Between
UP PIN 9 - PIN 13,
PIN 1 - PIN 11,
PIN 9 - PIN 12
MIRROR SELECT SWITCH IN ªLEFTº
POSITION
LEFT PIN 9 - PIN 8,
PIN 1 - PIN 11,
PIN 9 - PIN 7
DOWN PIN 9 - PIN 1,
PIN 13 - PIN 11,
PIN 12 - PIN 11
RIGHT PIN 9 - PIN 1,
PIN 8 - PIN 11,
PIN 7 - PIN 11
(4) If results shown in the table are not obtained,
replace the switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove instrument panel lower cover.
(3) From behind headlamp switch assembly,
depress retaining tabs and push switch from instru-
ment panel.
(4) Disconnect wire connector from power mirror
switch.
(5) Disengage lock tabs above and below the mir-
ror switch.
(6) Remove power mirror switch from headlamp
switch bezel.
INSTALLATION
(1) Install power mirror switch to the headlamp
switch bezel.
(2) Connect wire connector to the power mirror
switch.
(3) Insert headlamp switch assembly into instru-
ment panel.
(4) Install instrument panel lower cover.
(5) Connect battery negative cable.
SIDEVIEW MIRROR
REMOVAL
For service procedures, (Refer to 23 - BODY/EXTE-
RIOR/SIDE VIEW MIRROR - REMOVAL).
Fig. 4 Mirror Switch
RSPOWER MIRRORS8N-49
POWER FOLDAWAY MIRROR SWITCH - EXPORT (Continued)
The power seat system includes the following com-
ponents:
²Power seat recliners
²Power seat switches
²Power seat tracks
²Circuit breaker
The power seat system with memory and heated
seat options includes the following components:
²Power seat recliner
²Power seat switch
²Power seat track.
²Memory Seat Mirror Module (MSMM)
²Memory set switch
²Heated Seat Module (HSM)
²Heated seat switch
²Electronic Vehicle Information Center (EVIC)
²Programmable Communications Interface (PCI)
data bus network
Refer to Wiring Diagrams for complete circuit dia-
grams. Following are general descriptions and opera-
tions for the major components in the power seat
system and memory seat system.
DESCRIPTION - MEMORY SYSTEM
An electronic memory system is available on some
models. The memory system is able to store and
recall the driver side power seat positions (including
the power recliner position) and both outside side
view mirrors positions for two drivers. On vehicles
equipped with a factory radio, the memory system is
also able to store and recall radio station presets fortwo drivers. The memory system also will store and
recall the last station listened to for each driver, even
if it is not one of the preset stations.
The memory system will automatically return to
its preset settings when the corresponding numbered
button of the memory switch is depressed, or when
the doors are unlocked using the corresponding
Remote Keyless Entry (RKE) transmitter. A customer
programmable feature of the memory system allows
the RKE recall of memory features to be disabled, if
desired. This programmable feature is internal in the
EVIC module, which is located in the overhead con-
sole.
A Memory Seat Mirror Module (MSMM) is used on
some models to control and integrate the many elec-
tronic functions and features included in the memory
seat and mirror systems.
The memory system includes the following compo-
nents:
²Memory Seat Mirror Module (MSMM)
²Memory set switch
²Position potentiometers on both outside side
view mirrors
²Position potentiometers on the driver side power
seat track and power seat recliner motors.
²Electronic Vehicle Information Center (EVIC)
²Radio receiver (if PCI data bus capable).
Certain functions of the memory system rely upon
resources shared with other electronic modules in the
vehicle over the Programmable Communications
Interface (PCI) J1850 data bus network. The PCI
data bus network allows the sharing of sensor infor-
mation. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
Initial diagnosis of these electronic modules or the
PCI data bus network requires the use of a DRBIIIt
scan tool and the proper Diagnostic Procedures man-
ual. If this method does not prove conclusive, the use
of a automotive meter such as the Fluket, the proper
wiring schematics and the service manual diagnostic
routines are required.
The other electronic modules that may affect mem-
ory system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
²Powertrain Control Module (PCM)- Refer to
Powertrain Control Modulein Electronic Control
Modules for more information.
²Transmission Control Module (TCM)- Refer
toTransmission Control Modulein Electronic
Control Modules for more information.
Fig. 1 Identifying a Side Airbag Equipped Seat
1 - Airbag Label
RSPOWER SEAT SYSTEM8N-51
POWER SEAT SYSTEM (Continued)
Refer toHeated Seat Systemfor more informa-
tion on the heated seat system. Refer toRemote
Keyless Entry Systemin Power Lock Systems for
more information on the RKE system.
Refer toWiring Diagramsfor complete circuit
diagrams. Following are descriptions, theory of oper-
ation, diagnosis/testing procedures and removal/in-
stallation procedures of the major components in the
memory and power seat systems.
OPERATION
OPERATION - POWER SEAT SYSTEM
The power seat system receives battery current
through fuse #22 in the Intelligent Power Module
and a circuit breaker under the front seats, regard-
less of the ignition switch position.
When a power seat switch control knob or knobs
are actuated, a battery feed and a ground path are
applied through the switch contacts to the appropri-
ate power seat track adjuster motor. The selected
adjuster motor operates to move the seat track
through its drive unit in the selected direction until
the switch is released, or until the travel limit of the
seat track 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 seat track has reached its travel
limit. The power seat track each contain a self-reset-
ting circuit breaker to protect them from overload.
However, consecutive or frequent resetting of the cir-
cuit breaker must not be allowed to continue, or the
motor may be damaged. Refer to the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
OPERATION - MEMORY SYSTEM
The Memory Seat Mirror Module (MSMM) receives
battery current through fuse #22 in the Intelligent
Power Module and the power seat system circuit
breaker, located under the driver side front seat near
the rear edge of the seat cushion pan. The memory
system does not operate with the Ignition-Off Draw
(IOD) fuse removed. The MSMM will drive a maxi-
mum of 2 motors at a time in a given direction. If
conflicting directions are requested, the priority for
response will be approximately as follows:
²Seat Track Rearward or Forward
²Seat Front Down or Up
²Seat Rear Down or Up
²Recliner Rearward or ForwardThe inputs from these switches to the MSMM is a
current limited battery source fed by the MSMM.
This protects the MSMM printed circuit board traces
from acting as fuses. All of these switch contact
inputs to the MSMM are normally closed to ground,
except when actuated.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the memory system. For diagnosis of the MSMM,
the PCI data bus, or the other electronic modules on
the PCI data bus that provide inputs and outputs for
the memory system, the use of a DRBIIItscan tool
and the proper Diagnostic Procedures manual are
recommended.
ELECTRONIC VEHICLE INFORMATION CENTER
The Electronic Vehicle Information Center (EVIC)
serves as the user interface for the memory system.
It displays memory system status messages and pro-
vides the user with the means for enabling and dis-
abling the many customer programmable features
available on the vehicle, including those for the mem-
ory system.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the EVIC. Refer toElectronic Vehicle Informa-
tion Centerin Overhead Console Systems for more
information on the EVIC.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
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 DRBIIItscan tool
and the 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 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.
8N - 52 POWER SEAT SYSTEMRS
POWER SEAT SYSTEM (Continued)
(3) Reconnect the power seat wire harness connec-
tor to the power seat switch connector receptacle.
(4) Position the outboard seat cushion side shield
onto the seat cushion frame
(5) Install and tighten the 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) Install the switch knobs on the switch control
levers, if equipped.
(7) Reconnect the battery negative cable.
DRIVER POWER SEAT TRACK
DESCRIPTION
The eight-way driver side power seat option
includes a electrically operated power seat track
located under the driver side front seat. The front
power seat track on the driver side of the vehicle also
provides the mounting location for the Memory Seat/
Mirror Module (MSMM). The power seat circuit
breakers are mounted on the rear of the driver side
power seat track, just behind the seat rear trim
panel. The lower half of the power seat track is
secured to the floor panel via four studs and nuts
that must be accessed from the underside of the vehi-
cle. Four bolts secure the bottom of the seat cushion
pan to the upper half of the power seat track unit.
Four additional bolts secure the seat back frame to
the power seat track unit.
The power seat track unit includes four 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 four power seat
track motors used on models equipped with the
optional memory system incorporates a position
potentiometer integral to the motor assembly, which
electronically monitors the motor position. This
enables the memory system to function by referenc-
ing the motor positions programmed into the memory
seat/mirror module.
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. A third motor is
the horizontal adjustment motor, which moves the
seat track in the forward and rearward directions.
The forth motor is the recliner adjustment motor,
which moves the seat back in the forward and rear-
ward directions.
The power seat track unit cannot be repaired, and
is serviced only as a complete unit. If any componentin this unit is faulty or damaged, the entire power
seat track unit must be replaced.
OPERATION
When the driver side power seat 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 direction 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 from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
See the owner's manual in the vehicle glove box for
more information on the power seat switch functions
and the seat adjusting procedures.
DIAGNOSIS AND TESTING - DRIVER POWER
SEAT TRACK
WARNING: SOME VEHICLES ARE EQUIPPED WITH
SEATBACK MOUNTED AIRBAGS. BEFORE
ATTEMPTING TO DIAGNOSE OR SERVICE ANY
SEAT OR POWER SEAT SYSTEM COMPONENT
YOU MUST FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE CABLE. THEN WAIT TWO MIN-
UTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE FURTHER SYSTEM SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO DO SO COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Actuate the driver side 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
Diagnosis and Testing Power Seat Switchin this
section. 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.
8N - 58 POWER SEAT SYSTEMRS
PASSENGER SEAT SWITCH (Continued)
TESTING POWER SEAT TRACK MOTORS
(1) Check the power seat circuit breaker under the
seat. 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 under the seat. If OK, go to Step 3. If
not OK, repair the open fused B(+) circuit to the fuse
in the Intelligent Power Module 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 under the seat 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 toDiagnosis
and Testing Power Seat Switchin this section. 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.
REMOVAL
WARNING: SOME VEHICLES ARE EQUIPPED WITH
SEATBACK MOUNTED AIRBAGS. BEFORE
ATTEMPTING TO DIAGNOSE OR SERVICE ANY
SEAT OR POWER SEAT SYSTEM COMPONENT
YOU MUST FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE CABLE. THEN WAIT TWO MIN-
UTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE FURTHER SYSTEM SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO DO SO COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Remove the appropriate seat from the vehicle
and place it on a clean work surface(Refer to 23 -
BODY/SEATS/SEAT - REMOVAL).
(2) If the vehicle is so equipped, remove the Mem-
ory Seat/Mirror Module (MSMM) retaining screws.
(3) If the vehicle is so equipped, disconnect the
MSMM electrical connectors and remove the MSMM
from the power seat track.
(4) Remove the rear fabric blocker trim panel from
the rear of the front seat.(5) Remove the seat side cover and power seat
switch as an assembly (Refer to 23 - BODY/SEATS/
SEAT CUSHION SIDE COVERS - REMOVAL).
(6) Disconnect all electrical connectors connecting
the power seat track to the seat assembly.
(7) Pull the seat back trim cover up slightly to
access and remove the two seat back frame mounting
bolts and also remove two seat back recliner bolts.
(8) Remove four seat track mounting bolts from
the seat cushion pan.
(9) Remove the power seat track from the seat.
INSTALLATION
(1) Position the seat cushion on the seat track.
(2) Install the four seat track retaining bolts in the
seat cushion pan. Torque the bolts to 28.5 N´m.
(3) Position the seat back and install the two seat
back frame mounting bolts and the two seat back
recliner bolts. Torque the bolts to 55 N´m.
(4) Route and connect the electrical connectors
between the power seat track and the seat assembly.
(5) Install the seat side cover and power seat
switch as an assembly (Refer to 23 - BODY/SEATS/
SEAT CUSHION SIDE COVERS - INSTALLATION).
(6) Install the rear fabric blocker trim panel on the
rear of the front seat.
(7) If the vehicle is so equipped, position the Mem-
ory Seat/Mirror Module (MSMM) and connect the
MSMM electrical connectors.
(8) Install the MSMM retaining screws.
(9) Install the seat assembly in the vehicle (Refer
to 23 - BODY/SEATS/SEAT - INSTALLATION).
PASSENGER POWER SEAT
TRACK
DESCRIPTION
The four-way passenger side power seat option
includes a electrically operated power seat track unit
located under the passenger side front seat. The
power seat circuit breaker is mounted on the rear of
the power seat track, just behind the seat rear trim
panel. The lower half of the power seat track is
secured to the floor panel via four studs and nuts
that must be accessed from the underside of the vehi-
cle. Four bolts secure the bottom of the seat cushion
frame to the upper half of the power seat track unit.
Four additional bolts secure the seat back frame to
the power seat track unit.
The passenger side power seat track unit includes
two 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. The horizontal
adjustment motor moves the seat track in the for-
RSPOWER SEAT SYSTEM8N-59
DRIVER POWER SEAT TRACK (Continued)
The power seat system includes the following com-
ponents: ² Power seat recliners
² Power seat switches
² Power seat tracks
² Circuit breaker
The power seat system with memory and heated
seat options includes the following components: ² Power seat recliner
² Power seat switch
² Power seat track.
² Memory Seat Mirror Module (MSMM)
² Memory set switch
² Heated Seat Module (HSM)
² Heated seat switch
² Electronic Vehicle Information Center (EVIC)
² Programmable Communications Interface (PCI)
data bus network Refer to Wiring Diagrams for complete circuit dia-
grams. Following are general descriptions and opera-
tions for the major components in the power seat
system and memory seat system.
DESCRIPTION - MEMORY SYSTEM
An electronic memory system is available on some
models. The memory system is able to store and
recall the driver side power seat positions (including
the power recliner position) and the driver outside
side view mirror position for two drivers. On vehicles
equipped with a factory radio, the memory system is also able to store and recall radio station presets for
two drivers. The memory system also will store and
recall the last station listened to for each driver, even
if it is not one of the preset stations.
The memory system will automatically return to
its preset settings when the corresponding numbered
button of the memory switch is depressed, or when
the doors are unlocked using the corresponding
Remote Keyless Entry (RKE) transmitter. A customer
programmable feature of the memory system allows
the RKE recall of memory features to be disabled, if
desired. This programmable feature is internal in the
EVIC module, which is located in the overhead con-
sole. A Memory Seat Mirror Module (MSMM) is used to
control and integrate the many electronic functions
and features included in the memory seat and mirror
systems. The memory system includes the following compo-
nents: ² Memory Seat Mirror Module (MSMM)
² Memory set switch
² Position potentiometers on the driver outside
side view mirror ² Position potentiometers on the driver side power
seat track and power seat recliner motors. ² Electronic Vehicle Information Center (EVIC)
² Radio receiver (if PCI data bus capable).
Certain functions of the memory system rely upon
resources shared with other electronic modules in the
vehicle over the Programmable Communications
Interface (PCI) J1850 data bus network. The PCI
data bus network allows the sharing of sensor infor-
mation. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
Initial diagnosis of these electronic modules or the
PCI data bus network requires the use of a DRBIII t
scan tool and the proper Diagnostic Procedures man-
ual. If this method does not prove conclusive, the use
of a automotive meter such as the Fluke t, the proper
wiring schematics and the service manual diagnostic
routines are required. The other electronic modules that may affect mem-
ory system operation are as follows: ² Body Control Module (BCM) - Refer toBody
Control Module in Electronic Control Modules for
more information. ² Powertrain Control Module (PCM) - Refer to
Powertrain Control Module in Electronic Control
Modules for more information. ² Transmission Control Module (TCM) - Refer
to Transmission Control Module in Electronic
Control Modules for more information.
Fig. 1 IDENTIFYING A SIDE AIRBAG EQUIPPED SEAT
1 - AIRBAG LABEL
8Ns - 8 POWER SEAT SYSTEMRS
POWER SEAT SYSTEM (Continued)
Refer toHeated Seat System for more informa-
tion on the heated seat system. Refer to Remote
Keyless Entry System in Power Lock Systems for
more information on the RKE system. Refer to Wiring Diagrams for complete circuit
diagrams. Following are descriptions, theory of oper-
ation, diagnosis/testing procedures and removal/in-
stallation procedures of the major components in the
memory and power seat systems.
OPERATION
OPERATION - POWER SEAT SYSTEM
The power seat system receives battery current
through fuse #22 in the Intelligent Power Module
and a circuit breaker under the front seats, regard-
less of the ignition switch position. When a power seat switch control knob or knobs
are actuated, a battery feed and a ground path are
applied through the switch contacts to the appropri-
ate power seat track adjuster motor. The selected
adjuster motor operates to move the seat track
through its drive unit in the selected direction until
the switch is released, or until the travel limit of the
seat track 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 seat track has reached its travel
limit. The power seat track each contain a self-reset-
ting circuit breaker to protect them from overload.
However, consecutive or frequent resetting of the cir-
cuit breaker must not be allowed to continue, or the
motor may be damaged. Refer to the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
OPERATION - MEMORY SYSTEM
The Memory Seat Mirror Module (MSMM) receives
battery current through fuse #22 in the Intelligent
Power Module and the power seat system circuit
breaker, located under the driver side front seat near
the rear edge of the seat cushion pan. The memory
system does not operate with the Ignition-Off Draw
(IOD) fuse removed. The MSMM will drive a maxi-
mum of 2 motors at a time in a given direction. If
conflicting directions are requested, the priority for
response will be approximately as follows: ² Seat Track Rearward or Forward
² Seat Front Down or Up
² Seat Rear Down or Up
² Recliner Rearward or Forward The inputs from these switches to the MSMM is a
current limited battery source fed by the MSMM.
This protects the MSMM printed circuit board traces
from acting as fuses. All of these switch contact
inputs to the MSMM are normally closed to ground,
except when actuated. See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the memory system. For diagnosis of the MSMM,
the PCI data bus, or the other electronic modules on
the PCI data bus that provide inputs and outputs for
the memory system, the use of a DRBIII tscan tool
and the proper Diagnostic Procedures manual are
recommended.
ELECTRONIC VEHICLE INFORMATION CENTER
The Electronic Vehicle Information Center (EVIC)
serves as the user interface for the memory system.
It displays memory system status messages and pro-
vides the user with the means for enabling and dis-
abling the many customer programmable features
available on the vehicle, including those for the mem-
ory system. See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the EVIC. Refer to Electronic Vehicle Informa-
tion Center in Overhead Console Systems for more
information on the EVIC.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
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 DRBIII tscan tool
and the proper Diagnostic Procedures manual. The
DRBIII tscan 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.
RS POWER SEAT SYSTEM8Ns-9
POWER SEAT SYSTEM (Continued)