Evaporator Temperature Sensor
WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
The PCM monitors the evaporator temperature sensor in order to detect a possible evaporator icing condition and to determine in-vehicle temperature. The PCM disables the compressor clutch if the temperature input does not correspond to a predetermined value.