Evaporator Temperature Sensor

WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The evaporator temperature sensor contains a thermistor. The resistance of this thermistor varies by a specific amount based on the evaporator temperature. The HVAC module measures a voltage ratio between the reference voltage it supplies to the sensor and the sensor voltage to determine this resistance and the associated evaporator temperature.

The HVAC module maintains evaporator core temperature and prevents the evaporator core from icing. This is accomplished by switching the A/C request signal off when the evaporator temperature sensor reading falls below acceptable levels (slightly above the freezing point of water), and by switching the A/C request signal on when the evaporator temperature rises above acceptable levels.

The evaporator temperature sensor electrical connector is located outside of the heater core and evaporator core housing behind the glove compartment, with the sensor pigtail leading into the housing to the sensor probe which is inserted between the evaporator core fins.

The evaporator temperature sensor is not available as a separate component. To install a new evaporator temperature sensor, a new heater core and evaporator core housing must be installed.