MOST Bus Fault Volvo S80

Sounds like a nasty data transmission issue. Had something similar with my old Audi A6. Radio, nav, parking sensors all went kaput. Like losing all your senses at once, right? Could be a bad unit on the fiber optics ring. Isolate it or you'll be chasing your tail.

When you had this with your Audi, did you find a specific control unit at fault, or was it a process of elimination? Trying to understand the diagnostic complexity.

Figuring out the specific unit was a pain. I ended up taking it to a workshop. They have the diagnostic tools to pinpoint the break in the MOST ring. Saved me a ton of time and frustration. Just get it checked properly.

Took your advice and had it diagnosed professionally. It was a faulty amplifier on the MOST bus. The repair cost about 1000€, including parts and labor. Not ideal, but the system is working again.