If it is going into limp mode the computer is detecting something is wrong internally with the ski and shutting it down to prevent more damage. If that is the case I would have to defer to a real mechanic. Your owners guide should talk about limp mode and how critical it is. If it is the DESS post, that is an easy fix. The thing you call a key is a DESS, and it attaches to a post, that kit is only about 40 bucks, or I should say the last one I looked at was 40 bucks.