Anyone understand why the CIS system has a coolant temp sensor? This is a switch type sensor. The idle speed does not change on these engines, cold, hot, AC on/off, neutral or in gear. It is a two-wire sensor with red and blue wires running through the right side gray connector to the CIS computer. My only thought is that, depending on temperature, the air valve may be held in a different position when the throttle is off idle. Not sure what that would achieve.