SOS Diagnostics has said that the main problem they have seen is that the skreem and ECU go out of sync. That it is rare anything happens to the skreem itself. From posts I have seen if it happens once to someone it seems to happen again. It does happen to Sprinter vehicles a lot. It does not seem to happen to Mercedes vehicles a lot but since Mercedes dealerships/parts departments still support it then maybe that is why we do not hear about it as often.