Hell to all. I am new to the forum and this is my first post. My wife has a brand new 2014 A4 and three months later she has noticed that this control **** is not working properly. I took it out myself today and have verified. In short, when one tries to increase or decrease the volume it will not do either, or it will mute, the MMI screen screen acts weirdly, or the system will shut off. The same thing happens if one tries to moot or turn off the radio via the button. We will obviously take it in but has anyone experienced this? It appears isolated to thos button as the volume and mute wheel buttons work fine. Thanks in advance.

 

doesn't happen with mine - also have a 2014

 

Sounds electronic, likely poor wiring or connectivity. I doubt it's a fuse (else the entire unit won't work).

I had some electronic issues with my radio/mmi unit and turns out mine was a fuse (my symptoms were not like yours)

Good luck