So I rigged up a switch for 'dealer mode' and went for a ride.
The only way I could get the code to come up is by doing this:
1. Flick switch to On
2. Turn on the bike
3. Go for a ride, wait for the FI light to come on indicating an error
4. With the FI light on, hold down the Select button until the time disappears and the error code is shown (approx 15 seconds)
Afterwards the time came back and the speedo changed to cHE and stayed like that until the bike was turned off.
I got the code 05 63, which is nothing like the codes in the manual you linked... Is there a different ECU in later GV650s that could give codes like this or have I shorted the wrong wires haha?
Otherwise if you happen to know what code is for, that's great.