P0657 Ford - dio suggestions

Question

truck will throw code po657 on start up and be in limp mode, when you shut it down and clear code koeo then restart truck trans will run normal. on 2nd restart code returns as well as limp mode, now if you clear code koer all goes back to normal.I checked both power and ground to mechatronic unit plug when condition is present and have communication with tcm so i know CAN lines are working, also all modules communicate. my verus Dio scanner,mitchell on demand as well as snap on sure track all say replace mechatronic unit,but thats a big dollar item and i want to be 100% first. thanks for any thoughts on this, Larry z : )