The FI (fault indicator) lights up when the ECU detects an error or implausible signal with one of the sensors. The only way to find out which sensor is to put the bike in dealer mode. Search for "dealer mode" and "paperclip" on this site to get an idea on how to do that.
Some of the errors reset themselves after an ignition cycle. No way to retrieve the error other than with specialist equipment in that case, and even then it sometimes doesn't work. So if you have one of those intermittent issues, DO NOT switch off the bike, but put the bike in dealer mode while the engine is running and the FI light illuminated.
Problem is that you need the ignition key to lift the seat, to access the dealer mode plug. So either carry a spare key or put some sort of extension - possibly with a switch - on the dealer mode plug. There's also no harm in riding around with dealer mode engaged all the time, other than losing one of the ODO displays for the dealer mode output (Cxx code).
Some of the errors reset themselves after an ignition cycle. No way to retrieve the error other than with specialist equipment in that case, and even then it sometimes doesn't work. So if you have one of those intermittent issues, DO NOT switch off the bike, but put the bike in dealer mode while the engine is running and the FI light illuminated.
Problem is that you need the ignition key to lift the seat, to access the dealer mode plug. So either carry a spare key or put some sort of extension - possibly with a switch - on the dealer mode plug. There's also no harm in riding around with dealer mode engaged all the time, other than losing one of the ODO displays for the dealer mode output (Cxx code).
