Memory Seats Description and Operation

The memory seat system consists of the following components: Driver seat adjuster switch Driver seat memory switch Seat memory control module Driver seat horizontal motor Driver seat front vertical motor Driver seat rear vertical motor Driver seat recline motor Driver Seat Adjuster Switch Ground is supplied at all times to the seat adjuster switch. Battery positive voltage is supplied at all times to the seat adjuster switch through a 10 A fuse located in the fuse block. When the seat adjuster switches are pressed, the appropriate signal message is sent to the seat memory control module, via a LIN message. The seat memory control module then commands the appropriate seat motor to move in response to the switch signal message. Seat Memory Control Module Power and Grounds Battery positive voltage is supplied at all times to the seat memory control module through a 30 A fuse located in the fuse block. This voltage is used by the module to apply power to the seat motor when commanded ON. Battery positive voltage is also applied at all times to the seat memory control module through a 10 A fuse located in the fuse block. This voltage is used to power up the module. Ground is provided to the seat memory control module through the module ground circuit and ground connection. Seat Motors There are 4 motors that move the position of the seat. These are the seat horizontal motor, seat front vertical motor, seat rear vertical motor, and the seat back recline motor. The horizontal motor moves the entire seat forward and rearward. The seat front vertical motor moves the front of the seat cushion up or down. The seat rear vertical motor moves the rear of the seat cushion up and down. The recline motor moves the angle of the seat back forward or rearward. The seat memory control module controls all seat motors via half bridges that are connected to a single power rail internal to the module. The module connects each of the seat motor outputs together when a seat motor is not in operation. The seat memory control module continually checks the motor control circuits for shorts to ground or voltage. If a fault is detected with a motor control circuit movement of the related motor is inhibited. All of the motors operate independently of each other. Each motor contains an electronic circuit breaker (PTC), which will reset only after voltage has been removed from the motor. All seat motors are reversible. For example, when a seat switch is pressed to move the entire seat forward, a signal is sent from the seat adjuster switch to the seat memory control module, via the LIN message. In response to this signal, the module applies battery voltage through the seat horizontal motor forward control circuit and ground through the seat horizontal motor rearward control circuit to the motor. The motor runs to drive the entire seat forward until the switch is released, the motor reaches the end of travel, or an obstruction prevents further seat movement. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All of the motors are powered this way. Position Detection

Note

There are no physical position sensors used to detect the seat position and movement. To monitor the seat position, the seat memory control module counts the electrical pulses of each seat motor. During seat motor operation, the electrical pulses are counted and the direction of the seat movement is monitored to determine the seat position. The seat memory control module determines seat position by keeping a running counter where movement in the forward/upward direction adds counts and movement in the rearward/down direction subtracts counts. The value of these counters, which represent seat positions, are stored in memory for future seat memory recall operation. During a memory seat position recall, the seat memory control module moves the seat in such a way to return it the stored counter value. Memory Functions

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The seat memory control module does not store the mirror, column, MBM, or HUD positions. The seat memory control sends a serial data messages to the respective modules to recall their locally stored memory position. In all power modes except crank, memory recalls can be initiated by pressing and holding one of the memory position buttons until the seat reaches the stored memory position associated with the activated button. This is called a supervised recall. The driver seat memory switch is supplied ground at all times. The seat memory control module supplies set and memory recall signal circuits to the seat memory switch. When a memory recall switch is pressed, the signal circuit from the seat memory control module is pulled low through the switch contacts and a series of resistors indicating the memory recall request. In response to this signal, the seat memory control module commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory. Refer to the Owner’s Manual for storing memory positions. Seat Entry Memory Recall and Seat Exit Memory Recall The seat memory control module will not perform Seat Entry Memory Recall and Seat Exit Memory Recall functions unless these options are enabled in vehicle personalization using the radio/HVAC controls. Refer to Instruments and Controls/Vehicle Personalization in the Owner’s Manual for the following memory personalization options: Seat Entry Memory Recall Seat Exit Memory Recall The radio/HVAC controls reports the seat memory recall option settings to the seat memory control module via serial data message. The module will then store the memory recall option setting and examine it before making a memory seat adjustment. The seat memory recall option setting stored within the module will not change until the seat memory recall option setting in vehicle personalization is changed. Memory Store and Recall Conditions

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Memory function requires a position be saved to the activated memory switch that is being recalled. Memory Store Preconditions: RUN power mode No Stuck or Active Switches (seat, mirror, column, HUD) No SIR Disable No Load Shed 3 No output motor drive faults detected No position plausibility faults detected No child lockout – rear Not limit switch fault No memory switch fault Memory ID is 1 or 2 Memory Recall Preconditions: No Stuck or Active Switches (seat, mirror, column, HUD) No SIR Disable No Load Shed 3 No output motor drive faults detected No position plausibility faults detected No child lockout – rear Not limit switch fault No memory switch fault Memory ID is 1 or 2 LIN communications Active Not currently performing a memory store A position has been saved to the recalled memory position Memory Recall Termination Conditions: Precondition no longer met Active memory button changed Recall completed Exceed the max allowed recall time (30 seconds) OTA Programming Requested Auto Memory Recall Preconditions:

Note

Auto Memory Recall is suspended during Start power mode. Valid Memory ID and Driver ID Valid Power Mode No Active or Stuck Switches No SIR disable Vehicle is Stopped No Load Shed 3 No ASIL – A output fault detected No position plausibility faults detected No child lockout – rear Not limit switch fault No memory switch fault A position has been saved to the recalled memory position Enabled for Current Driver Auto Memory Recall Termination Conditions: Precondition no longer met, except being Parked Exceed any recall completion times Vehicle On terminates Seat Exit Memory Vehicle Off terminates Seat Entry Memory OTA Programming Requested Memory Recall Termination Data Displays: The termination causes can be viewed through the Seat Memory Recall History data displays. The following are possible memory recall termination causes: No Recall Requested Seat Entry/Exit Recall Completed Memory Button 1 Recall Initiated Memory Button 1 Recall Completed Memory Button 2 Recall Initiated Memory Button 2 Recall Completed Memory Button Exit Recall Initiated Memory Button Exit Recall Completed Terminated by Other then following Memory switch stuck or Invalid Memory Switch (Not including SET) out of Range Memory SET switch Active or 1, 2, Exit switch changed Seat Switch Active or Stuck Mirror Switch Active or Stuck HUD Switch Active or Stuck No Position 1 stored No Position 2 Stored No Position Exit Stored Load Shed 3 Sir Disabled Limit Switch Active or Fault Seat Entry – Not Parked terminated Invalid Power Mode Seat Forward Rearward Motor Control Fault Seat Front Up/Down Motor Control Fault Seat Rear Up/Down Motor Control Fault Recline Forward Rearward Motor Control Fault Seat Front Up/Down Motor Position Fault Seat Rear Up/Down Motor Position Fault Recline Forward Rearward Motor Position Fault