RNS-510 was working perfectly then noticed it go abit funny with the GPS s/w freezing and going offroad (which I have noticed in the past) I went to adjust the volume via the steering wheel and no response. Powered off engine but found the unit stayed on and is almost like it's lost connection to the car eg. is working like the engine is off .....no steering wheel controls....won't power on or off with ignition...but works on it's own and even powers off while driving (guessing this is the 20min timeout or so)

Any ideas whats wrong??