IBR had issues in original 09/10's then that was fixed by different software and a different servo motor. Seems they lightened things up again maybe? The IBR motor in all cases is just big enough to move the gate swiftly. On top of that, the computer wants to see this happen in a set amount of time, if not it throws a code. It also needs to see it move to a very specific location, couple degrees short, throws a code. Either of these repeated a couple of times and it elects that it's unsafe and throws craft into limp.
Right now, mine, an 09 original IBR is functioning perfectly _if_ I don't actually brake at speed, then it will code. Before opening servo motor and re-lubing/loosening all moving parts it coded just on shifts It takes a lot more force at speed than simply moving the gate at idle. I've already confirmed that my gate is basically 'stiff'. It's an 09 with 140hrs on it. What I didn't know is the entire IBR gate is supposed to be rebuilt at the 100hr mark with new bushings and rollers.. I expect it to move smoothly and freely this fall when I do this.
If you boat in sandy areas or in and out of salt, I can see the various pivots and slides in the whole assembly stiffening up early and like I said, they seem to have built the servo motor just big enough to do the job, any stiffening in the gate assembly and it thinks somethings wrong. Codes will usually reflect too much amperage to move the gate, the gate not moving quickly enough or the gate not going to the requested location (may look like it is, but a few degrees short and computer says 'failed'..)