Well, due to the lack of replies, I'll throw in what we found. It appears that the code has to do with a heavy load on the motors or large current draw. Could be the brushes or a loose connection, but in our case, it was the brakes were adjusted too tight. I've heard that frequent ramp use or pushing skids on the floor can cause this code. There are other fixes involving adjustment of the controller, but those would be failing checking all other possibilities.