Humidity/In-car Temperature Sensor
WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
The humidity sensor consists of two sensors. One detects humidity and the other detects in-car temperature. When the climate control unit receives the signals of the in-car condition from the humidity sensor, and judges that the humidity in the vehicle is very low, the climate control unit controls the compressor to reduce engine power loss.