Transmission problems, code P0700

I replace valve body because and drive is going to 3,000 RPM's and then kicking in like it was in neutral. I use a refurbished valve body the mechanic that put it in did not test drive it, parked it and when I got it I started it I like never drive it into drive and basically it's still doing the same thing, but sometimes it's acting like it's trying to catch, but it's still not shifting gears. The code is reading P0700 that was before. Now so what should I look at?