GM Service Manual Online
For 1990-2009 cars only

The power seat system consists of the following components:

    • Seat Adjuster Switch
    • Seat Horizontal Motor
    • Seat Front Vertical Motor
    • Seat Rear Vertical Motor
    • SEAT Circuit Breaker 25 A

Seat Adjuster Switch

The seat switches provide both power and ground to the selected seat motors. Battery positive voltage is supplied at all times to the seat adjuster switch from the SEAT Circuit Breaker located in the IP fuse block. Ground is supplied to the seat adjuster switch through the switch ground circuit and G301.

Seat Motors

There are three seat position motors; the horizontal motor, front vertical motor, and the rear vertical motor. All of the seat motors operate independently of each other. The seat 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 up or down. Both vertical motors can also run simultaneously to move the entire seat up or down. Each motor contains an electronic circuit breaker (PTC), that opens the circuit in the event of a circuit overload and will reset only after voltage has been removed from the circuit.

Seat Operation

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 seat horizontal motor forward control circuit, and ground is applied through the rearward switch contacts and the seat horizontal motor rearward control circuit. The motor then runs to move 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. The seat front and rear vertical motors are also powered this way.