Temperature Regulation
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The ventilation cooling modules supply a 5 V reference voltage through the temperature sensor signal circuit and ground through the temperature sensor low reference circuit to the respective seat cushion and seat back temperature sensors. The sensors are variable resistors, their resistance varies as the temperature of the seat changes. When the temperature sensor resistance indicates to the ventilation module that the seat has reached the desired temperature, they will set the blower speed in order to maintain the desired temperature.