I have been thinking about this as Rudy didn't make VCO sound like a big thing and ODY board wouldn't needed it with a direct input for speed from the tach. So it really depends on what the RS System needs to trigger sounds.
So ERR has 3 different boards and they don't work in the wrong type of engine? I guess because they are back emf driven, but still wouldn't that be the input along with serial speed command? So you have to have a serial out from a Cruise M Motor driver to trigger diesel ramp up? G