This evaporator temperature sensor monitors the refrigerant temperature at the evaporator coil inside the air conditioning system. It sends a signal to the HVAC controller, which uses that reading to modulate the compressor clutch engagement and prevent evaporator freeze-up. A failed sensor causes erratic compressor cycling, reduced cooling output, or continuous compressor operation that can ice the coil. As an original AGCO component, the sensor's resistance curve matches the controller's calibration, so no adjustment or reprogramming is needed at installation.