GM Service Manual Online
For 1990-2009 cars only

Lumbar Support System Components

The lumbar support system for the driver and passenger seat consists of the following components:

    • Lumbar switch
    • Lumbar motor assembly

Lumbar Support System Operation

The lumbar support motors are operated by a 2 position switch in each seat. Battery positive voltage and ground is provided to the lumbar switch through a battery positive voltage circuit and ground circuit at each seat.

Each lumbar support motor contains 2 control circuits. The direction the motor operates, depends on how battery positive voltage and ground is applied to the control circuits of the motor. For example, when the lumbar switch is energized, battery positive voltage is supplied to one control circuit and ground is supplied to the other causing the lumbar support motor to move in one direction. When the lumbar switch is activated the other direction the polarity in the lumbar or bolster motor control circuits is reversed and that causes causing the motor to operate in the opposite direction.