Auxiliary In-Vehicle Temperature Sensor
WARNING: This page is about a different car, the 2016 Lincoln MKT. However, it is still accessible from the selected car via links, so may be relevant.
The auxiliary in-vehicle temperature sensor contains a thermistor, which measures the in-vehicle air temperature and sends that reading to the HVAC module. An aspirator hose is connected between the auxiliary heater core and evaporator core housing and the auxiliary in-vehicle temperature sensor. The aspirator hose uses airflow through the auxiliary heater core and evaporator core housing to create a Venturi-type suction to draw in vehicle air through the auxiliary in-vehicle temperature sensor (across the thermistor).