[AlkanNavigator]

Please let me explain what's on my mind.

I don't think there are any problems with cables or connections at the head unit.

If this were the case, you could never hear sound or command the head unit.

First of all, the first thing you should try is to reset the head unit. To do this, press and hold the volume up and down button for 15 seconds. This will reset the iDrive itself (reboot).

If your problem is not solved after trying this, you may need to visit the service for head unit control.