Since the temperature has been in the 75-80s in middle TN lately, I noticed something.. whenever I turn on the AUTO vents, the fan would blow on high even though my last setting was on lowest.

I didn't notice this during Winter. Is this a smart sensor that says "ok, it's really warm in the car, I need to blow cold air at max?" Or is there something wrong with my ventilation system??

 

AUTO means the cpu will decide what's necessary to acheive the temp setting you request. It makes the speed and fan choice for you. Not using auto will allow you to control things for yourself.

Not an easter egg or a flaw. It's AUTO.

 

What I found interesting though, on other occasions, when the interior of the car was just as warm, the fans do not start out high. That's why I didn't think "auto" controlled the fan speed as I didn't see consistency.

 

what auto does is bring the cabin temp to what you set. For example you set auto and 70 degrees, it will blow hot or cold air until it is 70 degrees in the cabin, and it will vary speed while doing it.