Chrysler Pacifica. Manual - part 523

PASSENGER SEAT SWITCH

DESCRIPTION

The passenger seat switch assembly includes up to

three switches ganged together in one compact
switch assembly. The switch is located on the passen-
gers front door trim panel. This seat switch assembly
can provide up to three resistive multiplexed inputs
into the passenger door module. These inputs control
the heated seat and power seat system functions,
depending on how the vehicle is equipped. All inputs
are hardwired resistive mux to the passenger door
module to decode axis direction or seat heat level.
The passenger door module sends out the system
requests over the Programmable Communications
Interface (PCI) data bus circuit. Refer to Passenger
Door Module or Memory Heated Seat Adjustable
Pedal Module in the Electronic Control Modules sec-
tion for additional information on these modules.

The switch assembly is secured to the back of the

front door trim panel (Fig. 4) with clips.

The

switch

assembly

cannot

adjusted

repaired. If one switch is damaged or faulty, the
entire seat switch assembly must be replaced.

OPERATION

The passenger seat switch has up to three momen-

tary switch buttons. The heated seat switch portion
of the switch is back-lit with Light-Emitting Diodes
(LED) for easy visibility. When any of the switch but-
tons are depressed, a resistance signal is sent to the
Passenger Door Module (PDM) via hard wired con-
nections. The passenger door module then sends the
request to the Memory Heated Seat Adjustable Pedal
Module (MHSAPM) via the PCI data bus circuit. The
MHSAPM is responsible for controlling the 12volt
battery source and ground path to the seat heating
elements or power seat track mounted motors to con-
trol the seat accordingly.

Any seat axis or seat heat inputs can be activated

at the same time (except contradictory inputs). The
passenger door module has two outputs to the seat
switch to indicate heat level (HI/LO). The power seat
system is operational in any ignition switch position.
The heated seat system only operates with the igni-
tion on. See the owner’s manual in the vehicle glove
box for more information on the seat switch functions
and the seat adjusting procedures.

DIAGNOSIS AND TESTING - PASSENGER SEAT
SWITCH

(1) Remove the passenger seat switch, refer to the

following Switch Removal procedure in this section.

(2) Using an ohmmeter, check the appropriate

ground circuit cavity of the power seat switch connec-
tor for continuity to ground. It should be present, If
OK go to Step 3 , If NOT OK repair the open ground
circuit as required.

(3) Using an voltmeter, check the appropriate 12v cir-

cuit cavity of the power seat switch connector for
approx. 12v. It should be present, If OK go to Step 4 , If
NOT OK repair the open voltage supply circuit as
required.

Fig. 4 CS Passenger Seat Switch

1 - Seat Cushion Adjuster
2 - Seat Back Adjuster

POWER SEAT SYSTEM

8N - 33

(4) Using an ohmmeter, check the Seat Switch

resistance values. If the values are not within spec,
replace the seat switch.

HEATED SEAT SWITCH

TESTING

SWITCH RESISTANCE

±4% PINS 10-4

8010 Ohms (8.010

Kohms)

2415 Ohms (2.415

Kohms)

POWER SEAT SWITCH

TESTING

PINS 8-4

SEAT CUSHION

REARWARD

8020 Ohms (8.020

Kohms)

SEAT CUSHION

FORWARD

2420 Ohms (2.420

Kohms)

POWER SEAT SWITCH

TESTING

PINS 7-4

RECLINER BACK

8030 Ohms (8.030

Kohms)

RECLINER FORWARD

2425 Ohms (2.425

Kohms)

REMOVAL

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the front door trim panel. Refer to the

Body section for the procedure.

(3) Disconnect the wire harness connector from the

door module. Depress the retaining tab and pull
straight apart.

(4) Press in the four clips that secure the seat

switch to the door trim panel.

(5) Remove the power seat switch from the trim

panel.

INSTALLATION

(1) Position the seat switch onto the door trim

panel. Press into place ensuring all four clips are
engaged.

(2) Reconnect the wire harness connector to the

door module.

(3) Install the front door trim panel. Refer to the

Body section for the procedure.

(4) Reconnect the battery negative cable.

PASSENGER POWER SEAT
TRACK

DESCRIPTION

The power seat option includes a electrically oper-

ated power seat track and motor assembly unit

located under each front seat. 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 vehicle. Four bolts secure the bot-
tom 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 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 CS passenger seat base
and seat back recliner can be adjusted forward and
backward.

One motor is the horizontal adjustment motor,

which moves the seat track in the forward and rear-
ward directions. The second motor is the recliner
adjustment motor, which moves the seat back in the
forward and rearward directions.

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.

OPERATION

When a power seat switch control knob is actuated,

a resistance signal is sent to the Passenger Door
Module via hard wired connections. The door module
then sends the request to the Memory Heated Seat
Adjustable Pedal Module (MHSAPM) via the PCI
data bus circuit. The MHSAPM is responsible for the
12v battery feed and ground path to the power seat
track 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.

DIAGNOSIS AND TESTING - PASSENGER
POWER SEAT TRACK

The most reliable, efficient, and accurate means to

diagnose the power seat system requires the use of a
DRB III

t scan tool and the proper Diagnostic Proce-

dures information. The DRB III

t scan tool can pro-

vide confirmation that the PCI data bus is functional,
that all of the electronic modules are sending and
receiving the proper messages on the PCI data bus
network, and that the power seat system is receiving
the proper hard wired inputs and relaying the proper
hard wired outputs to perform its system functions.

Following are tests that will help to diagnose the

hard wired components and circuits of the power seat
system. However, these tests may not prove conclu-
sive. In order to obtain conclusive testing of the
power seat system, the Programmable Communica-
tions Interface (PCI) data bus network and all of the

8N - 34

POWER SEAT SYSTEM

PASSENGER SEAT SWITCH (Continued)

electronic modules that provide inputs to, or receive
outputs

from

the

system

components

must

checked.

PRELIMINARY TESTS

(1) Obtain a DRB III

t scan tool and check for any

stored diagnostic trouble codes recorded in the mem-
ory heated seat adjustable pedal module. Follow the
procedures called out in the proper diagnostic proce-
dures manual to resolve if codes are present.

(1) If any power seat is not operational in any

direction, check the power seat circuit breaker,
located in the Integrated Power Module. If OK, go to
Step 2. Refer to the Power Distribution section for
circuit breaker diagnosis and testing procedure.

(2) Check for proper battery or electrical system

voltage. The CS is equipped with a low-voltage cut-
off feature. If the electrical system voltage drops
below a predetermined set-point (approx. 11.5v), the
power seat system will not function until the proper
system voltage has been restored. If OK, go to Step
4. Refer to the Battery System and/or Charging Sys-
tem section for testing instructions.

(3) Obtain a DRB III

t scan tool and energize each

seat track motor axis one at a time. If any axis stops
without hitting the end of travel, the potentiometer
signal for that axis may have an open, short or be
mis-wired. Check the wiring to that axis (module to
motor). Fix any wiring problems and retry that axis.
If a certain seat track motor is inoperational, apply
12v and a good ground source to the inop motor. If
the motor does not operate in either direction replace
the power seat track assembly. Refer to Wiring for
complete circuit diagrams.

REMOVAL

(1) Remove the passenger seat from the vehicle

(Refer to 23 - BODY/SEATS/SEAT - REMOVAL).

(2) Remove the rear fabric blocker trim panel from

the rear of the front seat.

(3) Remove the seat side cover assembly (Refer to

23 - BODY/SEATS/SEAT CUSHION SIDE COVERS -
REMOVAL).

(4) Disconnect all electrical connectors connecting

the power seat track to the seat assembly.

(5) Pull the seat back trim cover up slightly to

access and remove the two seat back frame mounting
bolts and seat back recliner bolts.

(6) Remove four seat track mounting bolts from

the seat cushion pan.

(7) 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 assembly (Refer to

23 - BODY/SEATS/SEAT CUSHION - INSTALLA-
TION).

(6) Install the rear fabric blocker trim panel on the

rear of the front seat.

(7) Install the seat assembly in the vehicle (Refer

to 23 - BODY/SEATS/SEAT - INSTALLATION).

RECLINER MOTOR

DESCRIPTION

The power seat option includes an electrically oper-

ated power seat back recliner mechanism. The power
seat recliner switch is integral to the power seat
switch assembly, but is actuated with a separate
switch knob.

The

power

seat

recliner

motor

assembly

mounted in the place of a seat hinge on the outboard
side of the seat (Fig. 5). 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 motor cannot be repaired.

If the unit is faulty or damaged, it must be replaced.

OPERATION

When the recliner switch control knob is actuated,

a resistance signal is sent to the appropriate Door
Module via hard wired connections. The door module
then sends the request to the Memory Heated Seat
Adjustable Pedal Module (MHSAPM) via the PCI
data bus circuit. The MHSAPM is responsible for the
12v battery feed and ground path to the power seat
recliner adjuster motor. The adjuster motor operates
to move the recliner mechanism through its drive
unit in the selected direction until the switch is
released, or until the travel limit of the adjuster is
reached.

The driver side power seat recliner motor used on

models equipped with the memory system also has a
position potentiometer integral to the motor assem-
bly, which electronically monitors the motor position.

DIAGNOSIS AND TESTING - RECLINER MOTOR

The most reliable, efficient, and accurate means to

diagnose the power seat system requires the use of a

POWER SEAT SYSTEM

8N - 35

PASSENGER POWER SEAT TRACK (Continued)

DRB III

t scan tool and the proper Diagnostic Proce-

dures manual. The DRB III

t scan tool can provide

confirmation that the PCI data bus is functional, that
the electronic modules are sending and receiving the
proper messages on the PCI data bus network, and
that the power seat system is receiving the proper
hard wired inputs and relaying the proper hard
wired outputs to perform system functions.

Following are tests that will help to diagnose the

components and circuits in the power seat system.
However, these tests may not prove conclusive. In
order to obtain conclusive testing of the power seat
system, the Programmable Communications Interface
(PCI) data bus network must be checked.

PRELIMINARY TESTS

(1) Obtain a DRB III

t scan tool and check for any

stored diagnostic trouble codes recorded in the mem-
ory (heated) seat adjustable pedal module. Follow the
procedures called out in the proper diagnostic proce-
dures manual to resolve if codes are present.

(1) If any power seat is not operational in any

(2) Check for proper battery or electrical system

(3) Obtain a DRB III

t scan tool and energize the

recliner motor. If the motor stops without hitting the
end of travel, the potentiometer signal for that axis
may have an open, short or be mis-wired. Check the
wiring to that axis (module to motor). Fix any wiring
problems and retry that axis. If the recliner motor is
inoperational, apply 12v and a good ground source to
the inop motor. If the motor does not operate in
either direction replace the recliner motor assembly.
Refer to Wiring for complete circuit diagrams.

REMOVAL

(1) Remove the seat back. Refer to the Body sec-

tion for the procedure.

(2) Disengage J-strap at base of seat cushion.
(3) Roll seat cushion cover upward to access bolts

attaching recliner to seat back frame.

(4) Remove bolts attaching recliner to seat back

frame.

(5) Separate recliner from seat.

INSTALLATION

(1) Position recliner assembly on seat frame.
(2) Install bolts attaching recliner to seat back

frame and tighten to 28 N·m (20 ft. lbs.).

(3) Roll seat cover downward.
(4) Engage J-strap at base of seat cushion.
(5) Install the seat back. Refer to the Body section

for the procedure.

Fig. 5 Power Seat Recliner and Track - Typical

1 - Seat Back Frame
2 - Seat Cushion Foam
3 - Recliner Motor
4 - Seat Cushion Frame
5 - Shield
6 - Power Seat Track

8N - 36

POWER SEAT SYSTEM

RECLINER MOTOR (Continued)

Content .. 521 522 523 524 ..