Lumbar Control Switch: Operation
WARNING: This page is about a different car, the 2004 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.
When the lumbar control switch is moved forward or rearward, a resistance signal is sent to the Driver Door Module via hard wired connections. The driver door module then sends the request to the Memory Heated Seat Adjustable Pedal Module (MHSAPM) via the PCI data bus circuit. The MHSAPM is responsible for controlling the 12v battery feed and ground path to the lumbar motor to control the seat back power lumbar mechanism accordingly.