Pacifica V6-3.8L VIN L (2005)
Seat Track: Description and Operation
Driver Power Seat Track
The power seat option includes a electrically operated power seat track and motor assembly. One seat track assembly is located under each front seat.
The driver side power seat track also provides the mounting location for the memory heated seat adjustable pedal module on this vehicle. 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
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 track
through a combination of worm-drive gearboxes and screw-type drive units. Each of the power seat track motors incorporates a integral position
potentiometer, which allows the memory heated seat adjustable pedal module to monitor the motor position. This enables the memory system to function
by referencing the motor positions programmed into the 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 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.
When a power seat switch control knob is actuated, a resistance signal is sent to the Driver Door Module via hard wired connections. The driver 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.