Mercedes A Klasse Diesel MOST Bus Audio Failure

I understand your predicament regarding the MOST bus fault. I encountered a similar issue some time ago. The MOST bus, or Media Oriented Systems Transport bus, is an automotive protocol used for multimedia networking in vehicles. If one control unit on the bus fails, it can disrupt the entire system. Have you attempted to isolate the faulty unit by systematically disconnecting each component on the MOST bus to see if the system recovers? Also, could you provide more detail on the specific error codes you retrieved during the car diagnostics?

Thanks for your reply. I haven't tried disconnecting each unit individually. I'm not entirely sure where all the components are located or the proper procedure. As for the error codes, I'd have to pull the report again, but from memory, it was a generic 'MOST bus communication error.' Was your issue also a complete audio and navigation failure, and if so, how did you pinpoint the faulty unit?

Indeed, my symptoms mirrored yours precisely: complete audio and navigation failure. Given the complexity of the MOST bus network, I would strongly advise against attempting self-diagnosis without expert knowledge and specialized tools. Incorrect handling can potentially exacerbate the problem or damage other electronic components. In my particular situation, the car diagnostics at the workshop pinpointed a faulty amplifier module. While it's tempting to try a DIY approach, the risk of further complications and the potential cost of misdiagnosis are considerable. Therefore, I recommend seeking professional assistance from a qualified Mercedes-Benz technician.

Thanks again for your advice. I suspected as much, regarding the complexity of the MOST bus. I'll take it to a trusted mechanic specializing in car electronics for proper car diagnostics. I'll report back with the final resolution. Hopefully, it won't cost me more than the initial estimate!