Tcm replacement gone bad help

Hi all. I recently bought an 07 xterra. After some research I thought the problem could be the transmission control module. Me and a friend of mine just replaced it and the install was fine. when we went to take it for a drive, we noticed the transmission was slipping severely and there was a burning smell in the car. I need to get this car fixed asap so if anyone can help I would really appreciate it. Yes it has fluid around 4 quarts.