another issue, i am not sure how the comms work here but on some data moving platforms, modbus comes to mind, as does other control and data systems. data is crunched into digital words or vectors of words, if a value is never intended to be less than zero, then the value sign is typically not included, (no need to),but if something happens and you DO throw a negative number in there, the value sign (that would be + / -) gets injected into an integer slot, and that extra bit/byte of data, shifts everything over a slot. So then with direct address mapping, ie fpm is in word 4 bytes 3 4 and 5, since the - shifted everything, the real value is now stored in 456, but you are looking in 345. what's now in 3? what was in the next value chunk that is now also shifted? see how this could quickly turn catastrophic to the process? typically in better control systems there is some sort of error trapping to prevent this, and i doubt something like this would happen on a bike, but just as an example of how 'bad inputs' can cascade other expectations as well. again, not sure but... this type scenario with a bad throttle input, could in theory, be the cause of the other error messages you see as well as other data gets corrupted by the shift as well. to know for sure you'd have to know what all is represented by that data word.
without knowing the specifics of the system one has to take broad / general troubleshooting steps to try to narrow down stuff such as look to see if it is going below zero etc. process control troubleshooting can very quickly lead to baldness as one rips their hair out!
the throttle, is there some sort of zero stop on it for movement? something adjustable that one can tweak to let it move a smidge to zero out or is it all done electronically? that's a hall sensor isn't it? i never really looked.
aaron