Dead BMW i4 Screen: MOST Bus Mystery Needs Solving

Hi there! I had a similar issue with my 2019 BMW iX3 last month. The MOST bus failure completely knocked out my entertainment system too. My diagnostic also showed multiple control unit errors. Turned out the fiber optic ring was damaged, causing communication failures between modules. The main culprit was a faulty amplifier unit that was disrupting the entire MOST network. The repair involved replacing the amplifier and checking all fiber optic connections. It was quite a serious issue since it affected multiple systems, but it's fixable. Make sure your mechanic has experience with BMW's MOST bus diagnostics, they'll need specific diagnostic tools to properly identify which control unit is causing the cascade failure. When I took mine in, I specifically asked about their experience with BMW electrical systems and MOST networks. They showed me the damaged components afterward, helped me understand what went wrong. Hope this helps with your i4. These issues can be tricky to diagnose without proper equipment. Best regards

Thanks so much for sharing your experience! That's really helpful as it sounds exactly like what I'm experiencing. I'm relieved to hear it was fixable in your case. Would you mind sharing what the repair ended up costing you? Also curious if you've had any other electrical gremlins pop up since getting it fixed? Definitely taking your advice about finding someone with proper BMW diagnostic equipment and MOST bus experience. Knowing about the amplifier unit being a potential culprit gives me something specific to mention when I talk to mechanics.

Hey again! Great to hear back from you! Just wanted to update that I did get my iX3 fixed and haven't had any electrical issues since. The repair cost me 1000 € to replace that faulty control unit in the MOST bus system. Worth every penny though, the entertainment system has been working flawlessly for over a month now. The mechanic did a thorough job testing everything after the repair. No more error messages or system failures. It's such a relief to have everything working properly again, you know how frustrating it is when you can't even get basic audio working! I remember being worried about other potential issues popping up, but honestly, once they fixed that control unit problem, everything else fell into place. The whole MOST bus network is running smoothly now. Really hope you get yours sorted soon. Just make sure they properly test the system after the repair, that was key in my case. Let me know how it goes! Cheers!

Just wanted to update everyone, got my i4 fixed today and you were spot on! Took it to a certified BMW specialist who immediately recognized the MOST bus issue. They found a faulty control module that was messing up the whole system. The repair ended up running about 1200 €, bit more than expected but totally worth it. The mechanic was great, showed me the damaged parts and explained everything clearly. They even ran multiple tests afterward to make sure everything was communicating properly. Best part? The entertainment system is working perfectly now, got my music, nav, everything back! Such a relief after driving in complete silence for weeks. No other electrical issues have popped up either. Thanks again for steering me in the right direction with your advice about finding someone with proper diagnostic equipment. Really helped me avoid another bad mechanic experience. Would have been lost without your input! Take care!