If the display flashes there is a fault you have to plug it into vag com which will give you a fault code which you can look up and determin what is wrong, you cant dertermin the fault from how many flashes you are getting, its just doing that to tell you there is a fault, if you note the settings that you set after its stopped flashing are not resumed when you next switch it on, this is beacuse there is a fault, Vag Com all the way! Most mobile people do it for 35 quid, if your in devon I can do it for you, VW is about 50 quid,