Memory Positioning Systems: Description and Operation

POWER SEAT SYSTEMS
Power seats can be adjusted in 8 different directions:
- Up or down
- Forward or back
- Tilt forward or rearward
- Recliner up or down

Two single armature permanent magnet reversible motors are coupled through cables to worm gear box assemblies. They are located in the seat tracks and upper supports. The two single gear motor assemblies attach to the seat tracks provide the various seat movements.

The electrical circuit is protected by a 20 amp circuit breaker located on the Junction Block and a 40 amp fuse in the Power Distribution Center.

POSITION SENSING POWER SEAT POTENTIOMETERS
A potentiometer is mounted to each seat motor to provide a sense voltage to the MHSMM that will indicate where the actual seat position is.

This sense voltage is derived from a 5 - volt source provided by the module to the potentiometer. The MHSMM reads this sense voltage and stores it if required.

Power Seat Switch:

POWER SEAT SWITCH
The seat switch assembly is mounted outboard in the seat cushion side cover.

Activating any seat switch will move the seat in the corresponding direction. The MHSMM will drive a maximum of two motors at a time in a given direction. If conflicting directions are requested, the priorities for responses are as follows:

- Seat Track Rearward
- Seat Front Down
- Seat Rear Down Seat Recliner Rearward
- Seat Track Forward
- Seat Front Up
- Seat Rear Up
- Seat Recliner Forward

MEMORY SEAT SYSTEM
The Memory Heated Seat and Mirror Module (MHSMM) is located underneath the front of the driver seat. It is mounted unto the bottom of the seat by two screws. The connections to the system are through a seat wiring harness that interfaces with all of the components within the seat structure.

The MHSMM system allows the driver to adjust the seat, both driver and passenger side mirrors, and the radio stations to his/her preference and store them in memory. There are two memory locations available for two driver positions to be stored. The module will also allow either of the two positions to be recalled upon request.

The MHSMM reads all seat switch inputs and operates the seat motors according to which switch is being actuated. The MHSMM monitors position sensing potentiometers (mounted on the motors) for seat track positioning.

The MHSMM uses solid state drivers (electronic switches) to control motor activation for both driver and passenger side mirrors. Each mirror has vertical and horizontal motors, that contain potentiometers used to located the actual mirror position for recall purposes. Normal electrical operation of the mirrors is accomplished by actuating the power mirror switch and doesn't require the use of the module.

The MHSMM monitors the memory switches and has the capability to store desired positions in memory in response to a valid input sequence. Refer to Memory Selector Switches (1, 2, and S) and Remote Keyless Entry (RKE). The memory heated seat and mirror module will activate the seat and mirror motors in response to a recall request from an individual memory switch. The positioning of the motors is determined by the potentiometer values stored in memory.

The module operates the seat motors through relays: four dedicated to track horizontal forward/ rearward, front vertical up/down, rear vertical up/down, and recliner forward/rearward. A fifth relay controls the direction of operation of these motors.

GLIDE FEATURE
The MHSMM shall incorporate a seat glide feature. When exiting the vehicle and the ignition switch is removed, the glide feature will then activate.

This feature will allow easier entry and exit to the vehicle by moving the seat rearward a short distance when the operator leaves the vehicle and returning the seat to its original position when the vehicle operator returns and turns the ignition ON or extends their seat belt.

Memory Selector Switch:

Memory Selector Switch Location:

MEMORY SELECTOR SWITCH
The memory selector switches are mounted on the cushion cover side shield of the driver eat within easy reach of the driver. They provide a means to set and recall either of the two positions of seat and recliner, and the side view mirror as chosen by the driver.

The proper procedure of setting and recalling a memory position using the memory switches is as follows:
1. Adjust the seat, recliner and side view mirrors to the desired position.
2. Press momentarily and release memory switch S.
3. Press momentarily and release memory switch 1 or 2.
4. To program the second driver's position, repeat the above procedure using the remaining memory switch.
5. To recall either of the programmed positions momentarily press and release either memory selector switch 1 or 2.