Audi SQ5 Audio Dead: MMI System Complete Failure

I had a similar issue with my 2013 S5 last year and can share my experience fixing the sound system problems. Having worked on basic car maintenance, I would say I have some experience but am not an expert. The faulty wiring in the head unit was causing speaker crackle and complete audio failure. After troubleshooting basic things like fuses and checking Bluetooth problems, I took it to a specialist workshop. The diagnosis showed the display unit was defective and needed replacing, which also affected the volume control system. The total repair came to 725 Euro, including: New display unit, Programming and coding, System testing Before suggesting specific solutions for your SQ5, it would help to know: Does the display turn on at all? Are there any visible signs of damage to the control panel? Have you had any recent electrical work done? Does the steering wheel audio control still work? What exact error message appears? This should help identify if you are dealing with the same root cause or a different audio system issue.

Thanks for the detailed response. Just had my service at 92028KM last month. Following your questions: The display works fine but shows Error Code 28A. No visible damage to any controls. The strange thing is the static noise appears briefly when starting the car before the audio cuts completely. Steering wheel controls are also unresponsive. My main concern is the complete lack of sound despite the system appearing to power up normally. I checked basic stuff like fuses but the audio quality remains nonexistent. No recent electrical work done that could explain the faulty wiring. Given the symptoms match your experience, I might need to prepare for a similar repair cost.

Based on the Error Code 28A and the symptoms you described, it sounds exactly like what I experienced with my sound system. The static noise at startup is a telltale sign of the failing head unit, just like in my case, where the audio would briefly crackle before cutting out completely. The fact your display works but the volume control and car speakers remain unresponsive points to an internal circuit board issue rather than just faulty wiring. In my repair, they found oxidation on the main board connections inside the head unit, which caused similar symptoms. Your mileage is close to when my issue occurred (around 90000km), which suggests this might be a common failure point for our model's audio system. The dashboard controls and steering wheel buttons becoming unresponsive is another matching symptom. Looking at your case, I would expect the repair costs to be similar to what I paid (725 Euro), possibly slightly higher now. The good news is that after replacing the head unit, the problem never returned and the sound quality actually improved compared to before the failure. Just make sure the workshop does a full system diagnosis first, in rare cases, the amplifier can cause similar symptoms, though the Error Code 28A strongly suggests its the head unit itself.

Thanks again for the confirmation. This matches what I was worried about, seems like I need to budget for a full head unit replacement. The static noise at startup was definitely concerning me the most, so its reassuring to hear this is a known issue. Will book it in with a specialist workshop this week. The fact that your repair lasted and even improved the sound quality gives me confidence its worth fixing properly rather than trying cheaper alternatives. Good to know the 725 Euro price range is typical for this repair. Quick follow up, did your sound system take long to repair once they had the parts? Need to plan whether I should arrange alternative transport while its being fixed.