I have always swapped the problem car SIO board with a secondary controller SIO, never the master. Having said that, your situation seems odd for this known problem. Typically it's only one car out of a group. I have a ton of groups on service and it always been a secondary or non decision making 3rd controller with overhead problems. Oddly enough, after making the swap, the car receiving the suspect board wouldn't have issues then moving forward 80% of the time. If the problem did walk, then I would throw a new SIO in and was always good after that. Never needed any $$$$ software fix. Let me know how your situation turns out.

Thanks will keep you updated

After doing the board swap it appears nothing changed. Car still goes into overhead in the middle of the nite without ever a passenger

Sorry to hear that turbo. Just did this to another bank of 3 this last week which corrected the overhead issue. Sounded like all your elevators were having the same issue some more than others. Different from any over head issue I have dealt with. It was worth a shot for you though.

I do believe the SIO find is a good one. But I also know after working on these,that there is still a software problem. When they first came out, they were analog. I had no issues going into the overhead. I believe that problem started when they went digital. Also after they went digital they were parallel connected, no SIO board. One car would go into the overhead intermittently. Never could get around the fact that the NTS system didn,t work.

Yeah my cars do not have SIO boards. But they definitely do drive themselves into overhead. You can see it on the tool program