No idea how to fix, but it should ring when you have a call (mutes the stereo and you hear ringing), you should hear ringing when you phone someone as well, and when you take the key out it should switch off (I think mine stays on for about 5 secs, says "goodbye" or "disconnected" on the screen and then goes blank). Great piece of kit, but it shouldn't do what yours is at the moment, but sorry no clue how to fix it, mine was installed for me.