Hmm, now I’m very curious. When I did the swap I read the only communication ecu made to trans was NSS and maybe reverse lights. When it all worked out I scraped the truck, should have kept the ecu just in case.Im going to agree again with @lil_Blue_Ford on the ECM thing.
When i bought one for my ranger they accidently gave me an auto ECM...it didnt feel right at all, You could tell the computer was looking for things to happen that just wernt going to happen.

