BMW 6 Series MOST Bus Failure Kills Entertainment System

Hey there! I had the exact same issue with my 2007 BMW 5 Series diesel last winter. The MOST bus failure completely killed my entertainment system, same symptoms as yours. After diagnostic tests, they found a defective fiber optic control unit that was disrupting the entire MOST network. My mechanic explained that these control units can fail due to age and heat stress. In my case, they had to replace the main MOST module and reprogram the system. It was definitely a serious issue since it affected multiple connected systems, but it's totally fixable. Looking at your symptoms, it sounds identical to what I experienced. The error codes and complete system shutdown are typical signs of a MOST bus failure. Make sure whoever works on it has experience with BMW fiber optic systems, it's not your regular electrical repair. Just wanted to share my experience since I've been through it. Hope this helps with your decision-making. Best of luck with the repair.

Thanks so much for sharing your experience! That's super helpful to know it was the fiber optic control unit in your case, sounds exactly like what I'm dealing with. Would you mind sharing what the repair ended up costing you? Also curious if you've had any other issues pop up with the entertainment system since getting it fixed?

Hey again! Good news, I can give you the full update since getting mine fixed. The repair cost me 1000 € for replacing the faulty control unit in the MOST bus system, but it was totally worth it. Since getting it sorted, my entertainment system has been running perfectly, no glitches, no dropouts, nothing. It's like having a brand new system! I remember being worried about other issues popping up, but honestly, once they replaced that defective control unit, all my problems disappeared. The radio, navigation, and sound system are all working like they should. It's such a relief not having to deal with a dead entertainment system anymore. My advice would be to just bite the bullet and get it fixed. These BMW systems are pretty reliable once you sort out the original issue. Plus, driving without any entertainment or navigation is just no fun at all! Let me know if you end up getting it fixed, would be curious to hear if your experience turns out similar to mine.

Thanks again for all the details! Finally got my BMW fixed last week. I actually got lucky, turned out to be just a loose connection in the fiber optic cable, not the entire control unit. The mechanic I found was really experienced with BMW systems and spotted the issue right away. Only cost me 300 € for the diagnostic and repair work. It's such a relief having everything working again. The sound system is crystal clear now, and the navigation is back up and running. You're right, driving without entertainment was really getting old! The mechanic also checked the whole MOST system while he was at it and said everything else looked solid. Really glad I took your advice and found someone who knew what they were doing with these systems. Definitely feeling better about the whole situation now. Thanks again for helping me figure this out, saved me a lot of worry!