can anyone tell me what this part is, mounted to the side of the cabin filter housing on my '03 A6?

thanks in advance,

steve

 

I have no idea, but I can tell you my 00 doesn't have one

 

any body help with this?

 

It is an air quality sensor. If you set your climate control to the circle with the A in it, this sensor will measure the air quality and automatically open or close the outside vent.

I just had to replace that thing for 100$ because it quit working and threw a soft code.

 

cool, thanks. i was always curious how the car new about the air quality for the automatic setting. thanks again...

steve