SOS Call System Malfunction

My 06 5251 began experiencing audio cut outs with SOS Call System Malfunction being displayed. Then audio cut outs ceased but the SOS Call system Malfunction stays lit and now there is a msg that says high battery drain. As far as I know, my BMW Assist is not active. I've taken the car to a German auto mechanic and to a auto radio repair service. German mechanic said problem is in fiber optics, but he did not have tool to isolate where problem is. Radio repair expert could not determine what problem was.

Anyone know a fix to this problem other than going to dealer? I originally took my car there when I experienced bluetooth problems and they could not find the problem.

I had the same problem occurred to me in two occasions but no message was displayed about battery, it was just the radio not working and the SOS, but I noticed that it was on mornings when humidity was high, so I think that's probably what the issue was with the electronics on this vehicles, the warning went away after a couple miles driving.

Try the E60 Forum....maybe someone there can offer a suggestion.