Hands-free device / voice control defective

Hi,
has not been here for a long time, the V8 time has been a little...

I just got a phenomenon with my D2 BJ. 2002, the last series almost, because the voice control and the hands-free device no longer works.

So the push on the steering wheel button stays without action and the phone is displayed when someone calls, but it doesn't ring and I don't hear the language either. If I take the phone, the phone goes normal.

With more detailed consideration, this has been the battery lesson since the other day and I had to bridge.

After that, I put the phone several times during active conversation (rarely so often called my own answering machine, hehe) into place, normally the hands-free system is reactivated - but now no longer.

And as I said, voice commands don't work anymore.

Has anyone ever seen this before? Ideas? Is this by chance the same control unit for voice command and acquittal, which could be through by bridging or similar? Ideas? I'm okay with fuses.

So thank you for all the suggestions - and many greetings to the old rabbits ;-)

Alex