Memory Seat System

WARNING: This page is about a different car, the 2022 Chrysler Voyager and 2022 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.

The Memory Seat Module (MSM) receives battery current through a fuse located in the Power Distribution Center (PDC) and remains operational, regardless if the vehicle is running or not. When a driver memory seat switch button is actuated, a resistance signal is sent to the MSM over the Controller Area Network (CAN) Interior High Speed (IHS) bus. The MSM is responsible for the battery feed and ground path to the power seat adjuster motors. The adjuster motors operate to move the power seat to the correct preset location.

The MSM receives memory set/position switch input over the CAN bus. The MSM also receives hard wired input from the hall effect sensors, mounted on each of the driver power seat adjuster motors, driver side view mirror motors and power adjustable steering column motors, when equipped. The programmed software in the module allows it to know where the seat/mirror/column is located in its designed travel by a pulse count generated from the hall effect sensors. This way, when the memory switch is pressed the module will power the seat adjuster/mirror/column 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 CAN IHS bus by the MSM.

A memory setting is saved by pressing the "set" button, then pressing either the memory "1" or "2" button within five 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" FOBIK 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.

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.

NOTE:

Anytime a new Memory Seat Module (MSM) or a driver power seat motor or seat track is replaced, the MSM must be cleared of all learned parameters using a scan tool and the Power Seat System Verification test must be performed.

The use of a scan tool is needed for diagnosis of the memory seat system, CAN IHS bus and other electronic modules.