Good day, folks. My 81 years young neighbor has a 93 Ford Escort Wagon I maintain for him. It has a 1.9 ltr, auto, and a/c. It suddenly stopped shifting into overdrive. Otherwise, it shifts fine. It does not have a selectable "off" switch for the OD. Is there a switch or sensor on the trans? The check engine light is not on. Thanks for any help. :confused: