1998 Toyota Camry 98 2 0l Transmission Problems Check Engine Light

I have a 98 Toyota Camry 2.0l with transmission problems. The problem is the check engine light comes on. The code is P0758. The light could come on right after you start the vehicle or when you driving down the road. I have already replaced the tranny with a used one out a junk yard and still have the same problem. Any suggestion would be greatful.