I'd definitely ask your dealer to look it up.
My approach to fault codes (not necessarily recommended!) is:
If it runs, run it.
If it doesn't run, restart it to see if it will then run.
If it doesn't run after restarting, call the dealer.
If the dealer doesn't know, email Adam.
26K miles and still running!
That said, I don't think my bike has ever thrown a B40 at me. Probably something about the battery and worth checking out...