GM Service Manual Online
For 1990-2009 cars only

There are 3 reversible motors operating the power seats:

    • The forward/back motor
        The forward/back motor moves the entire seat forward and back.
    • The front height motor
        The front height motor tilts the front of seat.
    • The rear height motor
        The rear height motor tilts the rear of the seat.

The front height motor and the rear height motor can be operated at the same time. When the middle of the power seat switch is moved up or down, the front and rear height motors move the entire seat up and down.

Motor Operation

    • When the forward position on the power seat switch is pressed, voltage is supplied from the DEFOG/SEATS circuit breaker 30A to the forward/back motor. This drives the motor forward. When the back position is pressed on the power seat switch, voltage is now applied through the supply voltage circuit of the driver power seat motor horizontal aft direction. The polarity is reversed causing the motor to run in the opposite direction. Operation of the individual front height motor and the rear height motor is identical to that of the forward/back motor.
    • The front height and the rear height can be operated at the same time through the power seat switch. When the middle of the power seat switch is pressed to the up position, voltage is supplied from the DEFOG/SEATS circuit breaker 30A. This drives both motors. The down position has identical operation to the up position except that power and ground are reversed.

Electronic Circuit Breaker (ECB)

    • Each motor contains an Electronic Circuit Breaker (ECB).
    • When the motor is overloaded, the ECB resistance increases until the circuit breaker opens.
    • When the overload is removed, the ECB closes and resistance returns to normal.