Having a problem with my 3.0 's auto transmission. It shifts repeatedly from drive to OD every 5 seconds then afterward won't shift into OD and the OD flashes.Any of you techs out there help me out?

 

the last time that happened to me and my little bronco it was a part in the transmission called te vacum control modulator. see if thats your prob. if it is it will end up costing 600 bucks or at least mine did with all the other little parts and that nasty thing called labor