I have 230,000 mile on the car and the transmission went out again. I found a totaled 2004 monte carlo with only 40,000 and decided to swap everything over to my grand prix. I had to change the wire harness and a few other parts. It was a simple operations. I started the car and it purred like a kitten again. After changing the oil in the motor and transmission I decided to take it out for a spin. 1st gear was a little hard and so was second but third wouldn't shift. I knew then that something was wrong. It pulled a p1810 code. I didn't thing that the solenoids in the transmission were bad because the car was functioning before it was wrecked. I found out later looking into it that the two transmissions were not really compatible. Is there any simple solutions to this or is it me looking for something else. I have heard of pcm changing and pin switching. Im at wits end on this. any help would be greatful.