Module, Memory Seat (MSM): Operation

The Memory Seat Module (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 and to the other memory system components.
The memory system remains operational, regardless of ignition position.

When a driver memory seat switch button or Remote Keyless Entry (RKE) transmitter button (when programmed) is pushed, signal is sent to the MSM over the Controller Area Network (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 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 the 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 transmission gear selector is not in the Park position. 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" Remote Keyless Entry (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 other memory system components, radio station pre-sets and power mirror positions.
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 MSM. The MSM will then position the driver seat to the pre-set location. When a Remote Keyless Entry (RKE) transmitter button is pressed, depending on which transmitter (number 1 or number 2), the KIN receiver sends the recall request and RKE number (number 1 or number 2) data message. The RKE transmitter function depends on if the MSM is programmed to trigger the recall.

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).
Select the desired memory profile (1) or (2)
Once the profile has been recalled, press and release the SET (S) button on the memory switch, then press and release the button (1) or (2) accordingly. "Memory Profile Set" (1 or 2) will display on the Instrument Panel Cluster (IPC) on vehicles equipped with the Electronic Vehicle Information Center (EVIC).
Press and release the LOCK button on the RKE transmitter within 10 seconds.

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 RKE transmitter and to add the new RKE transmitter, 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 Remote Keyless Entry (RKE) as well as linking the new Remote Keyless Entry (RKE). Remember that linking requires the key/Remote Keyless Entry (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 to the soft stop position. 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.
Moving the steering column upward to the soft stop position.

This is a customer programmable feature. The seat will return to the pre-set position when the ignition is pressed to RUN. The MSM "learns" the seat, mirror and column 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. If the MSM learned a maximum position as a result of an obstruction, as for instance if a large object was placed on the floor behind the seat, the MSM can relearn the "true" maximum position through manually operating the power seat after the obstruction is removed.

NOTE: It is normal for the power accessories contained in the MSM 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 Control Units (ECUs) in the vehicle over the CAN bus. The CAN bus allows the sharing of sensor information. This helps to reduce wire harness complexity, internal ECU 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 use of a scan tool is needed for diagnosis of the MSM, CAN bus and other ECUs. Refer to DRIVER MEMORY SEATS MODULE (MSMD), DIAGNOSTIC CODE INDEX .