roller sensors, hmmm are you sure you are reading the error code flashes correctly. The first series of flashes will be long so you count how many of those there are then how many short duration flashes follow. The long duration flashes equal multiple of ten (10) so one long flash equals ten (10), whereas two long flashes equals twenty (20). The short duration flashes are singles (multiples of one). Example two long flashes equal twenty (20), followed by two short flashes which would equal two (2). Add both together [20+2=22] and get twenty two (22). Sorry if I am telling you how to suck eggs. Just want to be sure you are calculating correctly. Let me know what you work out. Any help or questions just ask. I don't mind to help you out.