Electric shift help

Okay so I've got a 2013 Honda 420 electric shift. 4500 kilometres. This winter it started acting up. Lights would dim when winching. Was shifting very hard. Now it's all messed up. It will sometimes throw code 22 on the gear indicator. Reverse works fine but hardly goes into other gears and when it does it doesn't work for long. Battery? Shift motor? Angle sensor? Computer? You can hear the shift motor trying really hard. Also manual shifter doesn't work.