Principles of Operation

PRINCIPLES OF OPERATION

Power Seats With Memory

Seat Positioning - Seat Control Switch
The 6-way power seat is controlled by the driver seat module (DSM) only when the vehicle is equipped with the memory driver seat option. The DSM will power the forward/rearward or up/down motion of the motors until the corresponding seat control switch is released or until end of travel is reached.

Seat Positioning - Memory Feature
The memory driver seat feature allows the driver to program a personalized seat position that can be recalled using the memory switches or remote entry key fob. There are 2 memory settings possible. The adjustable pedal positions are also stored and recalled with the driver memory seat positions.

A power driver seat position can be stored at any time. To store the power driver seat positions to memory, the driver must move the seat to the preferred positions, using the driver seat control switch assembly. The driver must then depress the memory SET switch. In response to this, the DSM will activate the memory SET switch LED and initialize a 5.0 ±1.0-second timer. The driver then has 5.0 ±1.0-seconds to select a memory position.
- Memory switch 1 is selected by depressing and holding the memory number 1 for 100.0 milliseconds.
- Memory switch 2 is selected by depressing and holding the memory number 2 for 100.0 milliseconds.

If no memory switch input is received within the 5.0 ±1.0-second time limit, the operation is aborted and the memory SET switch LED is turned off.

If one of the following inputs is received during the 5.0-second programming window, the operation is aborted and the memory SET switch LED is turned off:
- Power driver seat control switch
- Adjustable pedal switch
- Memory SET switch

Upon detection of a completed memory set process, the DSM will save power driver seat positions and adjustable pedal positions in the appropriate memory (1 or 2). The DSM derives seat position information (front height, rear height, forward/rearward) from the driver seat position sensors.

NOTE:
- A memory recall can only be initiated if the vehicle is in PARK or NEUTRAL and the ignition switch is not in START. An ongoing memory recall will not be affected by moving the ignition switch to START, nor by moving the gearshift lever out of PARK or NEUTRAL.
- Poor battery condition can interfere with memory seat operation, even if vehicle starting is possible.

Once the driver has stored a preferred driver seat position, the driver can recall the setting by depressing the corresponding memory switch or using a programmed remote keyless entry (RKE) key fob. The driver can recall a preferred driver seat position by one or both of the memory recall switches.
- Pressing and holding memory switch 1 for 150.0 milliseconds will initiate a recall of the power driver seat position stored in memory number 1.
- Pressing and holding memory switch 2 for 150.0 milliseconds will initiate a recall of the power driver seat position stored in memory number 2.

An RKE key fob (security module interface) can be used to recall previously set memory positions. The key fob assigned with personality No. 1 is only capable of recalling memory position 1. The personality No. 2 key fob can only recall memory position 2.

A remote key fob can be associated with a memory seat position by pressing a key fob button within 5 seconds after pressing the memory SET switch button (when setting a memory seat position).

Memory recall occurs when the unlock switch is pressed on the key fob. The second depression of the unlock switch, which unlocks passenger doors, does not initiate a memory recall.

An ongoing memory recall does not prohibit the initiation of another memory recall; the most recently requested memory recall will be executed. If the driver seat control switch is activated during a memory recall, the memory recall seat movement will stop and the switch commands will be executed. Activation of the memory SET switch or adjustable pedal switch will also cancel a memory recall in progress.

Memory positions that have not been programmed will not initiate any motion for the power driver seat or adjustable pedals.

The DSM is located under the driver seat cushion pan. When a new DSM is installed, it must be configured. Refer to Programmable Module Installation (PMI) in Information Bus (Module Communications Network). The DSM does not require calibration to the driver seat track.

Power Seats Without Memory
The 6-way power seat feature moves the seat in 6 possible directions: the base of the seat can be moved forward or backward and the front and back of the base cushion can be moved up and down independently. The power seat feature operates independent of the position of the ignition.

The power seat motors are hardwired to the seat control switch. The circuits are normally at ground through the seat control switch. An individual circuit is switched to power when a specific adjustment position is selected.

Heated Seats
The driver and passenger heated seat modules share a common battery feed and ground source and have a separate ignition feed. The electronic automatic temperature control (EATC) module includes the heated seat control buttons and indicators. The heated seat system will function when the EATC module is ON or OFF. When a heated seat control button on the EATC module is pressed with the ignition switch in RUN or START, a momentary ground signal is sent to the heated seat module. Upon receiving a signal, the heated seat module will decrease one setting (the sequence is HI, LO, OFF, HI, etc.). When a heated seat is set to HI, both LED indicators above the heated seat control button will illuminate. When a heated seat is set to LO, only the left LED indicator will illuminate. When a heated seat is set to OFF, neither LED will be illuminated. Refer to Heating and Air Conditioning.

When the heated seat system is ON, the heated seat module then supplies power to the heating element circuit. The cushion element and backrest element are wired in series and powered by the same output. The heated seat module will remain ON until the heated seat control button is pressed to cycle the heated seat module to the OFF state or until the heated seat module automatically shuts off after 10 minutes. If the ignition source is removed from the module, the heated seat module will enter an OFF state and will not return to ON until the heated seat control button is once again pressed with the ignition switch in RUN. The heated seat module is designed to heat the seat to 37.5°C (99.5°F) in LO setting and 42°C (107.6°F) in HI setting and maintain the temperature until switched OFF. This temperature is maintained by the heated seat module monitoring the temperature sensor, located in the seat cushion element, and adjusting the current flow to the heating elements.