Its The Encoder within the unit - How the guys in Berlin explained when I got my unit fixed, cost just over €100 with postage, also I didnt have a code for unit, instead of me going to MD, I got them to burn it, which left me with a memory code fault code on my unit, just a code - no errors,
At least I could listen to my unit in the first 15 mins of me driving.....
Units pull out with the correct keys - slip em in the front(bottom of front on unit) ---- feet on the dash - open the tailgate if you got an Avant ..... grin - tug - it will go eventually ........
