IAT reads the air temperature correctly. I am in Phoenix and it reads a few degrees above the outside air temperature. It was reading 93 degrees when I took these measurements which was pretty close to the outside air temperature. Colant temperature reads correctly. From a cold start it rises to 190 degrees. Coolant temperature stays between 190 and 201. Fan kicks in at temps above 201. I am using an AutoPHIX scanner to get these readings.