Power Seats With Memory
PRINCIPLES OF OPERATIONPOWER SEATS WITH MEMORY
Seat Positioning - Seat Control Switch
The six-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 motor 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 two 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 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.
If one of the following inputs is received during the 5.0 second programming window, the operation is aborted:
- 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 gear 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.
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 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 100.0 milliseconds will initiate a recall of the power driver seat position stored in memory number 1.
- Pressing and holding memory switch 2 for 100.0 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.
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.
Power Seat Calibration Test
The driver seat module (DSM) is calibrated using the scan tool. The calibration procedure automatically powers the driver power seat through its full range of motion and records the full stop positions by monitoring the motor position sensors. Once the full stop positions or range of the seat have been recorded, the DSM will only operate within the calibrated range. Any input attempting to drive the seat beyond the calibrated range will be ignored. This calibration is used for all seat control functions including manual switch control and memory recall positioning. During seat calibration the DSM may identify a function that is inoperative, such as a position sensor not changing. If the DSM identifies a concern that has a related diagnostic trouble code (DTC), the DSM will set the related DTC at the end of the validation procedure.
The calibration procedure powers the seat track adjustments to the end of their travel, which is determined by the DSM recording a change of state in the motor position sensors. If there is a concern with the seat track or motor position sensor that limits travel, the DSM will interpret the stopping point as the end of travel and store the position. The DSM is not able to determine if the seat has moved to its full travel position. It is only capable of monitoring and storing the amount of travel seen by the position sensor changing states.