For some reason when i have the AC on Auto, the circulation light comes on automatically... but when i turn the circulation off, the AC light goes off as well...

or it happens vice versa sometimes... If the AC is one and i turn on the circulation.. the AC light shuts off yet again..

my buddy tells me it's because theres a sensor in the filter that senses air pollution?

True or false??

 

There's a sensor, but it's not because of pollution lol!
If the car is hot inside, and you turn the AC to Auto, the recirculation will turn on as well because that's the fastest way for the AC system to achieve your selected temperature. Once it gets to that temp, then the recirculation turns off automatically and the temperature is maintained with fresh air.
This only happens if the interior temp is hot enough. So for instance, if it's 78 degrees outside, and your car was in the shade, and your AC temp is set to 76, it probably won't go into recirc. If it's 85 degrees outside and your car was in the sun, and you set your AC to 72, recirc will go on because it will be so hot inside that it would take too long to cool down to 72 otherwise.

Bottom line - Auto means auto... just set it and forget it. Let the computer take care of it

 

lol nice ok thanks, mods feel free for close this thread =]