Heater Mat
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The cushion heater mats are each equipped with a temperature sensor (thermistor) which provides feedback to the HVAC module (heated seats only) or DSM (heated/ventilated seats). The cushion and backrest heater mats are connected in series.