The memory seat system consists of the following components:

Battery positive voltage (B+) is supplied at all times to the MSM from two different voltage circuits. One circuit is fed by the SEATS Circuit Breaker located in the left underhood fuse block, and is used by the MSM to supply power to the seat motors. The second voltage circuit is fed by the BATT Fuse located in the rear fuse block, and is used to power the MSM. The MSM is grounded through the ground circuit and G 302.

The seat adjuster switch is grounded through the switch ground circuit and G 302. When the switch is operated to adjust the seat or recline position, the switch provides the selected switch signal circuit of the MSM a path to ground.

The MSM controls the movement of 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 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 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 cushion up and down. The recline motor moves the angle of the seat back forward and rearward.

All motors are reversible. For example, when the power seat switch is operated to move the entire seat forward, the power seat horizontal forward switch signal circuit of the MSM is pulled low through the switch contacts and ground. 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 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 other seat motors are also powered this way. The MSM also controls all of the seat motors during memory recall and easy exit functions.

The MSM provides each seat motor with a soft stop. The module will actually stop the motor just before the physical end-of-travel for that motor. This decreases the stress on each motor. If a motor reaches the end-of-travel due a soft stop and the seat switch is released and then activated again, the seat will move a short distance farther to the physical travel limit.

The seat position sensors are potentiometers which are attached directly to the motor's transmission cable. The MSM supplies a 5 reference voltage through the 5 volt reference circuit and ground through the low reference circuit to the respective seat position sensors. When the motor rotates the cable, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. This voltage varies from 0.5 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.

When a memory function switch is pressed, the associated signal circuit of the memory mirror module (MMM) is momentarily grounded. In response to this signal, the MMM then sends a message via the class 2 serial data line to the memory seat module (MSM) indicating that a memory function signal has been received.

The current seat position may be recorded for 2 different drivers. To record a seat position, adjust the drivers seat including the lumbar adjustments to a comfortable position, then press the SET button, within 5 seconds press button 1. A beep will sound each time a memory position is set. A second seating position may be programmed by repeating the above steps and pressing button 2. When the MSM receives a memory set message, the MSM records the feedback voltages from the seat and lumbar position sensors for the appropriate driver. Two easy exit positions can be programmed, one for each driver. The exit position is programmed by moving the seat to the desired exit position and then press the SET button followed by the EXIT button. When the MSM receives a set exit message, the MSM records the feedback voltages from the four seat position sensors for the appropriate driver. The lumbar support is not involved in the easy exit function.

When the memory 1or memory 2 button is pressed, a single beep is sounded through the radio speaker in order to acknowledge the command and the MSM receives the memory recall message. In response to this message, the MSM applies battery positive voltage (B+) and ground to the seat and lumbar motors until the position sensor feedback voltages equal the feedback voltages stored in memory for the appropriate driver. When the EXIT button is pressed, a single beep is sounded in order to acknowledge the signal and the MSM receives the easy exit message. In response to this message, the MSM applies battery positive voltage (B+) and ground to the seat motors until the position sensor feedback voltages equal the feedback voltages stored in memory for the appropriate driver.

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 MSM via a class 2 message. There are 2 personalized recall options when the MSM receives an unlock message:

The memory seat module receives the ignition switch signal and the gear selector position via class 2 messages. When the ignition switch is in the OFF position, memory record, memory recall, personalization recall, and easy 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.