Curious...when the car stopped below 3, did you notice if the two car call cancelled like it thought it was there? You say it stopped at two but didn't open the doors, then proceeded normally to 1 and opened. Does the problem always (reportedly) occur going down from 3? Selector Main Card or Auxiliary may be the culprit. Definitely need to chase the tool down and get your hands on a DMC Reference Guide or something comparable as there are way to many faults codes related to the Selector or CLC faults and erroneous signals. Routine the COP terminal strips and look for obvious CLC Card damage. Same in the Selector...check all molex type connectors. When you do get the tool, certainly a new hoist way scan may be in order just to eliminate that possibility.
Be sure to post when you resolve the trouble.