It is for diagnosis, you follow a procedure and it then flashes a certain number of times for what ever fault is recorded. I forgot the steps, something like turn on the key but don’t start bike or start it, turn off but leave key in the on position not turned all the way to the left…and so on. I think it’s detailed in the fuel injection supplement manual but I have not found that on line. Maybe it’s at this old tractor.com but last time I looked I didn’t see it.