Evaporator Temperature Sensor / Switch: Description and Operation

2.4L and RHD models equipped with A/C use an evaporator temperature sensor. The evaporator temperature sensor is a switch with a sensing probe that is inserted between the evaporator coil fins at the coldest point on the face of the A/C evaporator. The evaporator temperature sensor prevents condensate water on the evaporator coil from freezing and obstructing A/C system air flow by cycling the compressor clutch OFF when evaporator temperature drops below the freeze point. It cycles the compressor back ON when the evaporator temperature rises above the freeze point. The sensor probe is filled with a special silicone-based thermal grease. Three terminals within a molded plastic connector receptacle on the sensor connect it to the vehicle electrical system through a take out and connector of the HVAC wire harness. The evaporator temperature sensor can be replaced without having to remove the HVAC housing from the vehicle.

The evaporator temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.