DS4 Audio System Failure

Sounds frustrating! I had a similar issue with my 2018 Audi A3 a while back. The whole audio system just went silent. Did you try checking if the volume control is actually working or if it's just a display issue? For me, it turned out the main unit was faulty. I hope it's just a software glitch with yours. What kind of error message are you seeing?

Volume control does not work on the system, I tried to use physical control, and software control, both of them without reaction. The display itself seems okay, it lights up and shows the different menus, but there is no sound whatsoever. It's just that the speakers are silent. When you mention the main unit, are you talking about the display unit? Because I suspect the display is defective.

Yes, when I say main unit, I mean exactly the display unit. In my case the error logs pointed towards it and I found out that the internal sound amplifier was fried. Given that you've checked the fuses and the volume control is unresponsive, it really does sound like the unit has gone bad. A visit to the workshop is probably the best bet at this point. You can ask them to connect the car to their diagnosis tool to see where the errors are located.

Your experience with the Audi A3 gave me some confidence about asking for the right diagnostic. I went to the local shop, and they confirmed that it was indeed the display unit at fault. Apparently, this is a known issue and it cost me 725€ for parts and labor. At least everything is working fine now!