Originally Posted By moretoys
check fluid level.


I agree. Sounds like its low on fluid. If it was something else and set a code many times that will put the tans in Limp mode and it would lock in second or third gear and would not shift until you shut it off and restart it and if it was not a hard code then it would shift again. Course low on fluid can cause the code of "Loss of Prime" and may eventually set a code. Ron