Hi guys. Got a Otis E335M keeps stopping short on shut down 2006. STM FST TAST OVR. Very intermittent. My tool has no access to ocss on this controller. But did record DBSS. PCU loop fault Any ideas what my problem is ?

Does any one know what STM is?

You should have ocss. Make sure your plugged I into the ring car board. That board basically is ocss.

We dont have a lot of those controllers in my neck of the woods but I have had sone of those on my routes in the past. Somehow I remember stm being related to either the drive, encoder or speed sensing related. Im pretty sure those controllers have the speed boards in the back top right of the controller. There is also a speed relay on the right I believe. Make sure the relay contacts are good. If you have a speed board switch it with one from another controller and make sure your encoder coupling is good.

You would better check the encoder cable 's interference,or the port has been loosen.