The memory seat system consists of the following components:

The MSM is referenced in the Tech 2 as the driver position module (DPM).

The memory seat module (MSM) cannot perform memory recall functions unless the Personalization Option is enabled. The personalization is located in the radio (IRC). The radio reports the personalization setting to the MSM, as well as other receiving modules, via GMLAN message each time the ignition is cycled to the ON position. The MSM will then store the personalization option setting and examine it before making a memory seat adjustment. The personalization option setting stored within the MSM will not change until the personalization setting in the radio is changed.

Battery positive is supplied at all times to the seat adjuster switch from the DPM Fuse located in the left rear fuse block. When the power seat switches are pressed they send a 12-volt signal to the memory seat module (MSM). The MSM then commands the selected seat motor to move in response to the switch inputs.

Battery positive voltage is supplied at all times to the memory seat module (MSM) from the SEATS Circuit Breaker located in the left rear fuse block. This voltage is by the MSM to apply power to the seat motors when commanded. Battery positive is also supplied to the MSM from the DPM Fuse also located in the left rear fuse block. The MSM uses this voltage to power up the module. Ground is provided to the MSM through the ground circuit and G 307.

The memory seat module (MSM) controls the movement for each of the seat directional motors and the 2 lumbar motors. Refer to Lumbar Support Description and Operation . All of the motors operate independently of each other. Each seat motor contains a electronic circuit breaker (PTC), which will reset only after voltage has been removed from the motor.

There are 4 motors that move the position of the seat. These are the seat horizontal motor, front vertical motor, rear vertical motor and the recline motor. The horizontal motor moves the entire seat forward and rearward. Both vertical motors can run simultaneously when the seat switch is operated in order to move the entire seat up and down, or they can be selected independently to vertically tilt the front or rear of the seat up and down. The recline motor moves the angle of the seat back forward or rearward.

All seat motors are reversible. For example, when a seat switch is pressed to move the entire seat forward, battery positive voltage is applied through the power seat horizontal forward switch signal circuit to the MSM. In response to this signal, the MSM applies battery positive voltage through the driver seat horizontal motor forward control circuit and ground through the driver seat horizontal motor rearward control circuit to the motor. The motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All of the seat motors are powered this way.

Soft stop functions are not used for driver seat motors that are controlled by either a memory or non-memory MSM. However, soft stop functions are used for the MSM controlled steering column motors. Refer to Steering Wheel and Column Description and Operation in Steering Wheel and Column.

The seat position sensors are potentiometers that are either attached directly to the motor's transmission cable or are an internal part of the motor. The memory seat module (MSM) supplies a 5-volt reference voltage via the 5-volt reference circuit and ground via the sensor low reference circuit to the respective seat position sensors. When the motor or cable rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. The voltage varies from 0.25 volts to 4.75 volts. The MSM monitors this voltage signal to determine the position of the seat. When a memory set command is received, the MSM records the seat position by storing the feedback voltage from each position sensor. Then when a memory recall command is received, the MSM moves the motors until the position sensor feedback voltages equals the feedback voltages stored in memory. For the easy exit function, only seat position sensor feedback voltages are recorded and only the seat motors are controlled. The lumbar support is not involved in the easy exit function.

The memory feature will allow you to program and recall memory seat, steering column, and seat lumbar settings for up to 2 drivers. The memory seat module (MSM) will not respond to memory recall functions while manual positioning is in process. Any memory commands received during manual seat operation will be lost. The MSM may contain preset memory and exit positions for assembly plant testing until modified by a record memory operation.

The easy key module (EKM) identifies the driver and transmits the driver ID via GMLAN message to the radio and MSM. All voice activated memory recall and memory set commands are received by the MSM via GMLAN messages from the radio.

For vehicles with the base audio system, memory features are programmed and recalled through the radio from the DRIVER SELECTION and the DRIVER EXIT SETTINGS submenus. Refer to Radio/Audio System Description and Operation in Entertainment.

For vehicles with the Navigation system, memory features are programmed and recalled through the navigation display. Refer to Navigation System Description and Operation in Navigation Systems.

Also for vehicles with the Navigation System, you can recall memory features by using voice recognition. Refer to Vehicle Personalization in Personalization and to Navigation System Description and Operation in Navigation Systems.

Memory recall will not work if the shift lever is out of NEUTRAL (N) or PARK (P).

When a keyless entry transmitter is used in order to unlock the vehicle's doors, the remote keyless entry (RKE) module communicates the unlock command and which driver performed the command to the radio and memory seat module (MSM) via a GMLAN message. The following are 2 personalized recall options when the MSM receives an unlock message:

The memory seat module (MSM) receives the ignition switch signal and the gear selector position via GMLAN messages. When the ignition switch is in the OFF position, memory record, memory recall, personalization recall, and exit recall functions are all allowed. When the ignition switch is in the ON position and the gear selector is in the PARK position, only the recall personalization function is deactivated and all other memory functions are allowed. When the ignition switch is in the ON position and the gear selector is out of the PARK position, only memory record is allowed, all other memory seat functions are not allowed.