[StredTech]

Hello

I have a strange issue with my 420d GC.

When I got in it today, there was no audio. No chimes for parking sensors, nothing. The volume control does not even show on the screen when you try to adjust it - an its not on mute

Strangely, it has lost the date and time too, but only on the iDrive, the dash still has the correct date and time.

I have not plugged anything new in or changed anything so not sure why it would suddenly stop. I've seen a few other people post on here buy have not actually seen a resolution

Any help or ideas would be appreciated.
thanks

[Orion4]

Randon thought: How old is the battery? Have it tested. When these batteries start to go, we often get a myrid of strange electrical issues.

[StredTech]

Originally Posted by Orion4

Randon thought: How old is the battery? Have it tested. When these batteries start to go, we often get a myrid of strange electrical issues.

Battery is only 2 years old

[steve@codemybimmer]

You have an open circuit somewhere in the Most bus and the HK amp, head unit and instrument cluster all communicate through this fibre optic network so possible that one of these components had failed (likely the HK amp).

[StredTech]

Originally Posted by steve@codemybimmer

You have an open circuit somewhere in the Most bus and the HK amp, head unit and instrument cluster all communicate through this fibre optic network so possible that one of these components had failed (likely the HK amp).

Thanks for the heads up. Do you know of a way I can check to see what component it is? Is it likely to be a fuse?

[Billfitz]

You need an ODB diagnostic tool to read error codes that may pinpoint the fault.

[steve@codemybimmer]

Originally Posted by StredTech

Thanks for the heads up. Do you know of a way I can check to see what component it is? Is it likely to be a fuse?

MOST issues are usually tough to troubleshoot so I suggest getting a most loop terminator and going through each most component starting with the HK amp to see if the other components come back online.

If you terminate the HK amp and you notice that the warning tones, service and time comes back on the head unit then you know the Amp is causing the problem.

https://www.ebay.co.uk/itm/2x-MOST-F...75.c101224.m-1

[steve@codemybimmer]

Originally Posted by StredTech

Thanks for the heads up. Do you know of a way I can check to see what component it is? Is it likely to be a fuse?

Most bus issues are usually tough to troubleshoot so I suggest getting a most loop terminator and going through each most component starting with the HK amp to see if the other components come back online.

If you terminate the most connection on the HK amp and you notice that the warning tones, service and time comes back on the head unit then you know the Amp is causing the problem.

Search " Most loop terminator female " on eBay and you should be able to find these for under $10.

[StredTech]

Thanks all for the help!

I managed to fix it and thought I’d share the fix that worked for me rather than going silent

After pulling all the fuses relating to the audio and checking them I found they were all still good. I next turned my attention to the amp, I checked the connectors on it and when pushing the fibre connector I heard a click and then all the audio came back!

It looks like the connector wasn’t seated properly - phew!

[steve@codemybimmer]

Originally Posted by StredTech

Thanks all for the help!

I managed to fix it and thought I’d share the fix that worked for me rather than going silent

After pulling all the fuses relating to the audio and checking them I found they were all still good. I next turned my attention to the amp, I checked the connectors on it and when pushing the fibre connector I heard a click and then all the audio came back!

It looks like the connector wasn’t seated properly - phew!

Lucky

Yep, that would do it as well since the connection was loose causing the fibre loop to be disrupted.