we have a monospace that kept on faulting with i think edo faults coming up. lift would stop above or below level all the time but we would never actually catch it. it was also never stuck with passengers plus only happened at bottom and 2nd(of 4)floors. we went thru all range of things and just couldnt find it, cleaned tacho, adjusted brakes etc. we have an ex kone guy and he couldnt fix it either plus the controller had done its time and locked out. it ended up being after alot of spit balling/trial and error to be the load weigher on the standing ends. we added some test weights to the top of car and it hasnt faulted since!