Lumbar Circuit Description with Memory A45

Fig 1: Lumbar Support 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 adjuster switch. When the lumbar switch is pressed in the forward direction to inflate the lumbar support, the lumbar forward signal circuit from the seat memory control module is pulled low through the switch contacts indicating the lumbar inflate command. The seat memory control module then applies battery voltage through the lumbar inflate control circuit and ground through the lumbar deflate control circuit to the seat lumbar/bolster pump. The pump runs to inflate the lumbar support until the switch is released. When the lumbar switch is pressed in the rearward direction, the lumbar rearward signal circuit from the seat memory control module is pulled low indicating the lumbar deflate command. The seat memory control module then applies battery voltage through the lumbar deflate control circuit and ground through the lumbar inflate control circuit to the seat lumbar/bolster pump. The pump energizes its internal deflate solenoid and air is released from the lumbar bladder until the switch is released.