Description And Operation

DESCRIPTION

Courtesy of CHRYSLER GROUP, LLC

When equipped, the Memory Seat Module (MSM) (1) is located underneath the driver seat. It is used in conjunction with the other modules in the memory system to recall the driver seat to two different driver preset seat position preferences. The memory seat module is able to store and recall all driver side power seat positions (fore/aft, up/down, tilt and recline) and up to twelve radio station presets (six AM and six FM), on vehicles with a factory installed radio connected to the Controller Area Network (CAN)-IHS data bus network. The memory system will also store and recall the last radio station listened to for each driver, even if it is not one of the twelve preset stations.

If a memory profile is defined, the memory seat system will automatically recall the settings when a button of the memory switch located in the driver door trim panel is pressed, or when the doors are unlocked using the Remote Keyless Entry (RKE) transmitter (if the "RKE Linked to Memory" feature is 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.

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 (when programmed) is pushed, signal is sent to the MSM over the CAN-IHS bus. The MSM also receives hard-wired input from the hall effect sensors, mounted on each of the driver power seat adjuster motors. The programmed software in the MSM allows it to know where the driver seat, mirror and steering column are located in there designed travel by a pulse count, generated from hall effect sensors. This way, when a memory seat switch is pressed the MSM will power these components until the correct preset location is achieved. The MSM will prevent the seat memory recall function from being initiated, if the vehicle speed is greater than 0 mph/kph. These inputs are monitored over the CAN 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. The key needs to be out of the ignition in order for this setting to save.
A memory setting is recalled by pressing either the memory "1" or "2" button, or by pressing the unlock button on a "linked" RKE transmitter.

The MSM performs the following functions:

Positions the driver power seat (fore/aft, up/down, tilt and recline positions).
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.
Provides for the easy entry/exit feature.

When a memory button is pressed (number 1 or number 2) on the memory seat switch, it provides resistive signal to the BCM. The BCM sends a CAN message to the MSM. Then the MSM sends a CAN message to the radio to save the radio stations or recall the preset stations.

The resistive signal goes to the BCM (the body control module). And

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

Remove the Key Fob from the ignition (or change the ignition to OFF, for vehicles equipped with Keyless Enter-N-Go).
Press "set" first, then the desired memory profile "1" or "2".
Press and release the LOCK button on the RKE transmitter within 5 seconds of selecting the memory profile.

FOB LINKING

- The MSM has the capacity to store two linked fobs only. If one is lost or damage, a third can not be programmed successfully. In order to remove stored keys and to add the new key, the MSM module needs to forget what links already exist.

Unlink by pressing the SET (S) button, and within 10 seconds, followed by pushing the UNLOCK button on the RKE transmitter.

Once this has been completed, you will need to re-link the original RKE as well as linking the new RKE. Remember that linking requires the key/RKE to be out of the ignition.

EASY ENTRY/EXIT

- This feature enables the driver to comfortably enter and exit the vehicle by:

moving the seat cushion rearward. The maximum amount of rearward seat cushion movement will depend on the current position of the seat cushion at the time the Easy Entry/Exit feature is activated.

This is a customer programmable feature. 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.

NOTE:

It is normal for the power accessories contained in the memory system to stop at the maximum "learned" position and then continue to the "true" maximum position when the control switch is released and then applied in the same direction a second time.

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 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 ECU needs to be calibrated.

The use of a scan tool is needed for diagnosis of the MSM, CAN-IHS bus and other electronic modules. Refer to DIAGNOSIS AND TESTING .