Front Heated Seat System 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.

Depressing either of the two front door trim panel mounted, heated seat switches sends a hardwired, resistor multiplexed signal to the corresponding door module. The door module then sends a PCI data bus message to the Memory Heated Seat/Adjustable Pedal Module (MHSAPM). The module detects the heated seat switch status via the PCI data bus circuit and energizes the appropriate heated seat element. The programmed software in the MHSAPM allows it to know the temperature of the seat cushion by a resistance value generated from the heated seat temperature sensor. When the correct preset temperature set point is achieved the module will de-energize the heated seat element. The module will continue to toggle the heated seat element 12v supply ON and OFF to maintain the selected temperature of the seat.