GM Service Manual Online
For 1990-2009 cars only

The driver and passenger power seat systems each consist of the following components:

    • Seat Adjuster Switch
    • Seat Horizontal Motor
    • Seat Front Vertical Motor
    • Seat Rear Vertical Motor
    • Seat Recline Motor
    • Lumbar Motor (Passenger Seat only)
    • SEAT Circuit Breaker 20 A

Seat Adjuster Switch

Battery positive voltage is supplied at all times to the driver and front passenger seat adjuster switches through a 20 A circuit breaker located in the I/P fuse block. Ground is provided to both switches from the ground stakes. When active the seat adjuster switches provide both power and ground to the selected seat motors.

Seat Motors

All seat and lumbar motors operate independently of each other. Each motor contains an 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 four seat position motors and one lumbar motor. These are the horizontal motor, front vertical motor, rear vertical motor, seat back recline motor and the lumbar 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 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 while the lumbar motor moves the lumbar support forward and rearward.

All seat motors are reversible. For example, when the seat switch is operated to move the entire seat forward, battery positive voltage is applied through the switch contacts and the horizontal motor forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the 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 opposite circuits causing the motor to run in the opposite direction. All of the other seat and lumbar motors are powered this way.