XC90 MOST Bus Fault

I had a similar issue with my 2018 Audi A6. A MOST bus fault usually indicates a problem with one of the control units on that network. Have you checked the fuses?

Thanks for the quick reply! Which fuses should I be checking, specifically? And is there any way to isolate which control unit might be causing the problem?

Unfortunately, pinpointing the exact control unit requires specialized diagnostic equipment. I would not recommend trying to fix this yourself. See if you can bring the Volvo to a workshop.

Thanks, I appreciate the advice. I bit the bullet and took it to the workshop. Turns out it was a faulty amplifier on the MOST bus. Cost me 1000€ to get it sorted, but at least everything's working again!