GM Service Manual Online
For 1990-2009 cars only

Memory Seat System Components

The memory seat system consists of the following components:

    • Seat adjuster switch
    • Memory seat module
    • Driver seat adjuster motor assembly
    • Driver seat recliner motor

Memory Seat System Controls

The memory seat system is controlled by the following components:

    • Seat adjuster switch
    • Memory seat module

Memory Seat System Operation

The seat adjuster motors are controlled by the memory seat module through the adjuster motor supply circuits. Adjuster motor operation occurs when the memory seat module switches one of the adjuster motor supply circuits to battery positive voltage and the other to ground. The adjuster motors are reversible and the direction of the adjuster motor rotation is determined by which of the adjuster motor supply circuits is switched to battery positive voltage and which is grounded.

The seat adjuster switch is supplied with a ground circuit. When a seat adjuster switch is pressed the signal circuit is closed to the ground supply. Closing the switch signal circuit to ground pulls the signal circuit low indicating to the memory seat module the switch status is active. The memory seat module also uses the serial data circuit for diagnostic purposes and to send and receive messages which affects the memory seat system operation.

The seat adjuster motors are equipped with 2 types of position sensors. The position sensors for the horizontal motors, and the front and rear vertical motors are a 3 wire transducer type sensor. The position sensor for the recliner motor is internal to the motor and is a hall effect type sensor. The transducer position sensors are supplied with a 5 volt reference circuit and low reference circuit from the memory seat module. Whenever a memory seat module function is active the memory seat module receives a signal from each position sensor which varies from 0 to 5 volts depending on the seat position. The memory seat module uses the transducer position sensor signal voltage to determine the seat position when storing or recalling seat position settings. With the hall effect sensor for the recliner motor, the memory seat module monitors the same information to determine power seat position but instead of monitoring for changes in voltage readings, the memory seat module monitors pulse rates from the sensor.