You are the master of the road! - MAN errors The best-selling mobile application for MAN trucks and buses (including Neoplan) on a mobile phone including all fault codes, definitions and abbreviations. Type fault code in app search bar FFR 00647 and find a problem or example: EDC 03779-01, search 03779 or EDC 03779 (-01 additional tag, meaning you have in the app): Rail pressure: High leakage due to quantity compensation. Enter in the search box: FFR - Vehicle management computer.