Disconnected the battery and trans shifted different

[Daviddto]

When I purchased my 2004 Yukon the trans had a delayed hard shift into 2nd. I disconnected the battery and it shifted much better ( not delayed and smoother ). I disconnected the battery again and now it's shifting late and hard into 2nd. What could cause this problem? I know its electronic, I just don't know what.

 

[sbubbaklein]

every time you disconnect power the TCM has to relearn the shift points and slip characteristics. Drive it normally and it will relearn to your driving style

 

[Daviddto]

Thank you