Engine starts in P in On position. Cuts off and restarts without turning key on. ECU replaced. Unplugged connector below auto shift lever and seemed to correct issue. Replugged switch,drove 5 miles, no issues. Started next day, idles high in P, shifts, backin P and engine shuts off and restarts in On position without turning key and ˟˟˟˟s back off. Any suggestions?

 

how did you manage to work it out ?

 

I replaced the neutral safety switch in transmission housing. Full of water which caused intermittent issues. Seems to have corrected initial problem as well as some other fast idle issues. I think the new ECU needs time to learn the system and driving it is
has settled problem. Thx for asking.