Seat Motors

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

The memory seat module (MSM) controls the movement of each of the above mentioned seat directional motors. All of the seat motors operate independently of each other. Each motor contains a electronic circuit breaker (PTC), that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit.

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. The seat vertical motors may operate independently to tilt the front or rear of the seat cushion up or down. Both vertical motors can also run simultaneously to move the entire seat up or down. The recline motor moves the angle of the seat back forward or rearward.

All motors are reversible. For example, when the seat switch is operated to moved the entire seat forward, battery positive voltage is applied through the horizontal forward switch contacts and 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 to the horizontal motor. The MSM supplies ground to the motor through the driver seat horizontal motor rearward control circuit. 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 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 it's physical travel limit.