I've had this problem twice on my 95 Explorer and the first time I took it to a shop and after $180.00 which included change of filter and new trani oil, mechanic did pull the codes but was unable to figure out what was wrong. So, he disconnected the battery for about 5 minutes and everything was back to normal. One good point from Dayle is that when this happens you trani starts shifting harder which can lead to more serious problems. About a week ago after almost 1 year it did it again. This time I went ahead and remove the battery cables for about 5 minutes and truck is working fine. I figure if it happens a third time, then I will for sure take it in again for a checkup. Hope this info. works. Good Luck!!!