Memory Seat Module

DESCRIPTION 

Courtesy of CHRYSLER GROUP, LLC

The Memory Seat Module (MSM) (1), is located under the driver and passenger front seat. The MSM is able to store and recall all side power seat positions (fore/aft, up/down, lumbar, seat bolsters, cushion extender, seatback tilt and recline), and the driver side MSM can also recall pedal, and power adjustable column (if equipped). The memory seat module is also able to recall mirror positions and radio station presets on vehicles with a factory installed radio connected to the Controller Area Network - Interior High Speed (CAN-IHS) data bus network. Mirror positions and radio station presets are stored in the door control modules and radio respectively. The memory system will also recall the last radio station listened to for each driver, even if it is not one of the preset stations.

The passenger seat memory function us actuated using the passenger memory switch located on the passenger door trim, in front of the door handle and below the seat massage switch, if equipped.

If a memory profile is defined, the memory seat system will automatically recall the settings under the following conditions:

• When a button of the memory switch located in the driver door trim panel is pressed
• During a passive entry action
• When a radio recall action is requested
• When the doors are unlocked using the Remote Keyless Entry (RKE) transmitter

If the vehicle has more than two drivers the RKE transmitter recall of memory features can be disabled. This is a customer programmable feature.

OPERATION 

• The MSM receives battery current through a fuse in the Power Distribution Center (PDC).
• The MSM is responsible for the 12 volt Direct Current (DC) feed and ground path to the power seat adjuster motors.
• The memory system remains operational, regardless of ignition position.

When a driver memory seat switch button or RKE transmitter button (if programmed) is pushed, a signal is sent to the driver MSM over the CAN-IHS bus. The driver MSM also receives hardwired input from the hall effect sensors, mounted on each of the driver power seat adjuster motors. The position sensors in the seat and pedal motors allow the driver MSM to know where the driver seat and pedal are located. The mirror location is determined by potentiometers directly connected to the Door Control Module (DCM). The mirror location is stored in the DCM, which communicates via CAN-IHS with the driver MSM. When commanded to, the DCMs move the mirrors to one of the two memory profiles recalled by the driver MSM via CAN-IHS. This way, when a memory seat switch is pressed, the driver MSM will power these components until the correct preset location is achieved. The driver MSM will prevent the seat memory recall function from being initiated if the vehicle speed is greater than zero. These inputs are monitored over the CAN bus by the driver MSM.

The passenger MSM can only be activated using the memory switch on the passenger door panel. The passenger MSM works similarly to the driver MSM, but does not control the pedals, steering column or mirrors and is cannot be activated by a keyfob.

Saving a memory setting:

1. In any ignition position and with the vehicle in park.
2. Adjust all memory profile settings to desired preferences (for example, driver seat, cushion extender, bolsters, outside mirrors, adjustable pedals, and steering wheel tilt/extend, if equipped, and radio station presets).
3. Push and release the set (S) button on the memory switch.
4. Within 5 seconds, push and release either of the memory buttons 1 or 2. The instrument cluster display will show which memory position has been set.

The MSM performs the following functions:

• Positions the driver/passenger power seat (fore/aft, up/down, cushion extend, bolster angle, seat back tilt and recline positions).
• The driver MSM sends the memory save or recall (number 1 or number 2) command over the CAN data bus circuit to the radio for station pre-sets and to the DCMs for mirror recall.
• Easy entry/exit feature is by default available but set to OFF.

Key Fob Linking: 

1. Cycle the vehicle's ignition to the OFF position.
2. Select a desired memory profile, 1 or 2.
3. Once the profile has been recalled, push and release the set (S) button on the memory switch.
4. Within 5 seconds, push and release button (1) or (2) accordingly. "Memory Profile Set" (1 or 2) will display in the instrument cluster.
5. Push and release the lock button on the key fob within 10 seconds.

A key fob is "linked" to a memory setting by performing the following steps:

Key Fob Unlinking:  - This is a customer programmable feature.

The key fobs can be unlinked from the memory settings by pushing the set (S) button, and within 10 seconds, followed by pushing the unlock button on the key fob.

Easy Entry/Exit Seat  - This is a customer programmable feature.

This feature provides automatic driver seat positioning to enhance driver mobility when entering and exiting the vehicle.

The distance the driver seat moves depends on where the driver seat is positioned when the ignition is cycled.

The seat will return to the pre-set position when the ignition is pressed to RUN. The memory seat system "learns" the seat motors maximum end positions when the motor reaches the limit of travel in any direction and stalls. Subsequently, movement will stop just short of that position to avoid extra stress on the motors and mechanisms.

Certain functions and features of the memory seat system rely upon resources shared with other electronic modules in the vehicle over the CAN-IHS bus. The CAN-IHS 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, the memory seat system provides increased reliability, enhanced diagnostics and allows the addition of new feature capabilities.

The use of a diagnostic scan tool is needed for diagnosis of the MSM, CAN-IHS bus and other electronic modules. Refer to DIAGNOSTIC CODE INDEX .