Need IC pump info

[Romans8:28]

Guys,

What causes the IC pump to come on? I am guessing it has to do with temperature measured at IAT2?

I happened to be looking under my hood this morning and noticed no circulation in the IC reservoir. I put my hand on the blower and it was pretty cool (I could comfortably keep my hand on it), I had been dring the car easy (basically no/little boost) and the air temperature was in the 40's....

I suppose I will learn more this afternoon when it's hotter outside and I drive it a little harder to get the blower temps up, in the mean time I am curious

Thanks for any/all info

 

[ShelbyGuy]

Actually, its the ECT sensor to the best of my knowledge (Engine Coolant Temp) that signals the PCM to turn on the pump.

You can reach your hand up from underneath the front bumper cover near the driving light and feel if the pump is running.