Hi,

I have a 2007 Audi A3.

When I turn on the Climate Control (CC), I hear a low hissing sound coming from the Air Outlets in the center. The sound is more like what you hear when air blows into a hollow steel pipe. There is NO cold air.

The sound goes away as soon as I turn ON the ECON button.

Any idea what could be wrong?

Thanks!
PH.