Do you happen to know if the ECM in the 16 is the same? Any idea what all was changed with this update?
Looking at the wiring diagram there are couple of pins in the 17 model that aren't populated in the '16 model, they seem to be tied to the I-4wd. More specifically, pins 2. 12, and 27 in the large black connector. Pin 12 is labeled SW1 (DRV), I have no idea what those abbreviations mean.
There are also a 2 pins in the '16 ECM that have the words (Mode Change) next to them that isn't present on the '17. They are pin 1 and pin 7 in that same 33P black connector. That might have something to do with the keeping modes after shutting the unit down.
The only big issues I can ID off the bat about swapping ECM's is this: If you look at the diagnostic section the manual for a '17 and up machine several normal sensor values are different than a '16 model. So swapping the ECM could lead to multiple codes triggering that don't actually point to anything being wrong with the unit.
For instance DTC 8-1 TP Sensor Voltage Low, 2016 less then .298 volts 2017 and later .122 volts.
So swapping a 2017 ECM into a 2016 could possibly not trigger the code correctly if an issue in the TP sensor system comes up.
Edit: The pins I mentioned above don't have wires from the harness going to them on a 2016 model, so they wouldn't go anywhere. I haven't cross referenced any part numbers, but I think the ECM is the same with or without I-4wd, the unit just wouldn't have the wiring for it.