Memory Seat System

An electronic memory seat system is available on certain models. The memory system is able to store and recall all driver side power seat positions, outside mirror positions, power tilt/telescopic steering column positions and power adjustable pedal position. The system can be set for two different drivers. On vehicles with a factory installed radio connected to the Controller Area Network (CAN) data bus network, the memory system is also able to store and recall up to twelve radio station presets (six AM and six FM), also for two drivers. The memory system will also store and recall the last station listened to for each driver, even if it is not one of the twelve preset stations.

The memory system will automatically recall all of these settings when a button of the memory switch is depressed, or when the doors are unlocked using the Remote Keyless Entry (RKE) transmitter (if enabled). If the vehicle has more than two drivers the RKE transmitter recall of memory features can be disabled. This is a customer programmable feature of the Electronic Vehicle Information Center (EVIC) set through the use of the appropriate steering wheel switches.

The memory system also has an "Easy Entry and /Exit" feature that provides the driver with more room to enter or exit the vehicle. When the seat is in a memorized position, it will move rearward 55 millimeters or to the end of its travel, whichever occurs first, when the key is removed from the ignition switch lock cylinder. This is also a customer programmable feature of the Electronic Vehicle Information Center (EVIC) set through the use of the appropriate steering wheel switches.

The memory system also has a "Tilt in Reverse" feature that tilts the outside mirrors down a fixed, incremental angle when the vehicle is shifted into REVERSE with the ignition switch in the RUN position. This feature provides the customer with a better view of the ground and vehicle in the area of the rear tires when backing up. The mirrors move back to their previous position when the vehicle is shifted out of REVERSE.

The memory system includes the following components:
- Memory Selector Switch - located in the driver door trim panel.
- Driver Door Module (DDM) - located in the driver door, behind the trim panel.
- Passenger Door Module (PDM) - located in the passenger door, behind the trim panel.
- Hall Effect Sensors - Outside Mirror - The hall effect sensor is permanently installed on the outside mirror motor. This hall effect sensor is used to provide a reference signal to the memory heated seat mirror module, letting the module know the exact position of the mirror.
- Sentry Key Remote Entry Module (SKREEM) - located at ignition key cylinder.
- Remote Keyless Entry (RKE) Transmitter - located with ignition key.
- Memory Seat Module (MSM) - located underneath the driver seat and also controls the Adjustable Pedals.
- Hall Effect Sensors - Seat Track - These hall effect sensors are permanently installed in each of the power seat track motors. They are used to provide a reference signal to the memory heated seat mirror module, letting the module know the exact position of the seat cushion and recliner.
- Radio - located in the instrument panel center stack.
- Automatic Temperature Control (ATC) - located in the instrument panel center stack.

Certain functions and features of the memory system rely upon resources shared with other electronic modules in the vehicle over the Controller Area Network (CAN) bus. The CAN bus allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities. For diagnosis of these electronic modules or of the CAN bus, the use of a scan tool and the proper diagnostic information are needed.

The Memory Seat Module (MSM) receives battery current through a 25 amp circuit breaker in the Power Distribution Center (PDC) so that the power seats remain operational, regardless of the ignition switch position. When the driver memory seat switch control knob is actuated, a resistance signal is sent to the MSM via the Controller Area Network (CAN) bus circuit. The MSM is responsible for the 12v battery feed and ground path to the power seat adjuster motor. The adjuster motor operates to move the power seat adjuster mechanism through its drive unit in the selected direction until the switch is released, or until the travel limit of the adjuster is reached.

The MSM receives memory set/position switch input through the CAN bus circuit. The MSM also receives hard wired input from the hall effect sensors, mounted on each of the driver power seat adjuster motors and the driver side view mirror motor. The programmed software in the module allows it to know where the seat/mirror is located in its designed travel by a pulse count generated from the hall effect sensors. This way, when the memory switch is depressed the module will power the seat adjuster/mirror motors until the correct preset location is achieved. The module will prevent the seat memory recall function from being initiated, if the transmission gear selector lever is not in the Park position, or if the vehicle is moving. These inputs are monitored over the Controller Area Network (CAN) bus circuit by the MSM.

A memory setting is saved by pressing the "set" button, then pressing either the memory "1" or "2" button within 5 seconds of pressing the "set" button.

A memory setting is recalled by pressing either the memory "1" or "2" button, or by pressing the unlock button on a "linked" Remote Keyless Entry (RKE) transmitter.

For driver safety, memorized settings can not be recalled if the transmission is in a position other than Park or the seat belt is latched.