RS5 Audio System Failure: Dead Stereo & Error Messages

As someone with some hands-on experience in car electronics, I dealt with a similar issue on my 2017 RS4. The symptoms were nearly identical, complete audio system failure and error codes related to signal reception. After dealing with static noise and poor FM signal quality for about a week, I took it to a specialist workshop. The diagnostic revealed a defective antenna and damaged antenna ground connection. The radio reception problems were caused by corrosion at the antenna base, which completely disrupted the signal strength. The total repair came to 255 Euro, including: New antenna assembly, Labor for removal and installation, System diagnostic and reset Before you proceed with repairs, it would be helpful to know: Have you noticed any water damage or leaks near the antenna area? Does the issue persist when the car is stationary vs moving? Are you able to access the diagnostic codes? I suggest having a professional check the antenna ground connection first, as this is often the root cause of car radio problems. My repair took about 2 hours, and the audio system has worked flawlessly since. What specific error message are you seeing on your infotainment display? This could help pinpoint whether your issue matches what I experienced.

Thanks for the feedback. My mileage is now at 195220 KM and I checked the diagnostic codes last week. The error message shows MMI-0x4F212. I noticed the vehicle electronics seem more affected when driving in areas with weak signal coverage. A signal amplifier might help, but I want to be sure before investing in one. The antenna ground looks visually fine, but I havent checked for corrosion underneath. No water damage visible around the antenna area. Will probably need to get it properly diagnosed by a specialist to rule out more serious issues with the infotainment system.

Based on the error code and the fact that signal issues worsen in areas with weak coverage, it sounds exactly like what I experienced. The connection problems in my RS4 also fluctuated based on location, which initially made me think I needed a signal amplifier. The diagnostic code MMI-0x4F212 typically points to signal reception problems in the vehicle electronics system. While the antenna ground might look fine externally, the corrosion I found on my car was only visible after removing the antenna assembly. Before investing in an antenna booster, I recommend having a specialist test the actual signal strength at the head unit. In my case, installing a signal amplifier would have been a waste since the root cause was the corroded connection blocking the signal path. Your mileage is similar to what mine was when the issue occurred. These antenna grounds tend to deteriorate around the 180000-200000 km mark due to environmental exposure. The complete repair solved all my signal reception issues without needing additional signal boosting equipment. If you decide to go the repair route, make sure they thoroughly check all ground connections and antenna cables while the system is apart. The fact that your issues are related to signal coverage areas strongly suggests this is an antenna system problem rather than an infotainment unit failure, just like in my case.

Thanks everyone for the detailed responses. After getting the car checked by a specialist, you were right, it was indeed the antenna ground causing the problems. The technician found significant corrosion under the antenna mount that wasnt visible from the outside. Total repair cost was 290 Euro including parts and labor. They cleaned all connections, replaced the antenna assembly, and reset the car radio system. Static noise is completely gone now and signal strength is back to normal, even in areas that previously had poor reception. No need for an antenna booster after all. For anyone else having similar issues with signal reception in higher mileage vehicles, definitely worth checking the antenna ground connections first before assuming its an infotainment system failure.