Ambient Air Temperature Sensor
The ambient air temperature sensor is a negative temperature coefficient (NTC) thermistor that provides the automatic temperature control (ATC) module with an input of external air temperature. The sensor is hard wired to the engine control module (ECM) and its signal is transmitted to the instrument cluster on the high speed controller area network (CAN) bus. The instrument cluster acts as a gateway and transmits the ambient air temperature signal to the automatic temperature control (ATC) module on the medium speed controller area network (CAN) bus. The sensor is mounted on the vehicle center line behind the lower front grill, and can be accessed from underneath the vehicle.