this is a strange problem, we have a three car group, one of the cars was intermittently getting occupied, if the car was at the lobby and opened the door in response to a lobby hall call the passenger would enter and place a call, the doors would close, the car call remained latched but the car would not leave and become occupied, the door open button would not open the door. the only way to alleviate the problem would be to reset controller. after running the car for many hours, with not a problem, i became frustrated, so i stopped giving it car calls and decided to just watch it in its normal activity for the day. I got lucky, the traffic died down and the cars did not run for a good amount of time, that is when the cold oil circuit kicked in on the car i was looking at, and the controller began its warming of the oil, then a hall call was placed and a passenger entered the car and gave a car call and he was occupied. it turns out that all 3 cars will occupy a passenger if the car is at the lobby, and the cold oil circuit is initiated , and a lobby hall call is pressed, the door will open, the cold oil circuit will stop, the car call will be allowed, the door will close but the car will not run and occupy the person, we can duplicate this problem on all three cars. obviously it is a software problem, so we disable cold oil circuit and have had no further trouble, does any one have any info on this trouble