Lumbar Support Components

The driver seat lumbar support system with memory (A45) consists of the following components:

• Seat adjuster switch
• Seat memory control module
• Seat lumbar support horizontal motor

Fig 1: Lumbar System Block Diagram (With Memory A45)

Courtesy of GENERAL MOTORS COMPANY

Ground is supplied at all times to the driver seat adjuster switch through the switch ground circuit and ground connection. The seat memory control module supplies a low current voltage to each signal circuit of the seat lumbar support switch. When the seat switches are pressed, the appropriate signal circuit from the seat memory control module is pulled low through the switch contacts indicating the lumbar command. In response to this signal, the seat memory control module applies battery voltage through the driver seat lumbar motor forward control circuit and ground through the driver seat lumbar motor rearward control circuit to the motor. The motor runs to drive the lumbar support forward towards the occupants back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on the opposite