Does anyone know what "heighterror" means on a Yale order picker? I have one that has had many hands working on it and now the customer wants to have me look at it. I have a manual for the unit but it does not list this error the way it is displayed on the dash. The unit will intermittently travel and lift. But mostly shows this error with very slow or no travel or functions. The customer said he had a local Yale dealer send out a guy who spent a few days working on the lift...they replaced the on board computers and ran some sort of reset with the function handle?? They said it ran for about a week after the reset...also said it took him several times to get it to work.Does anyone know how to do this procedure? Any help would be greatly appreciated.