Originally Posted by NOVAX5

Use 30 secs reset method. It will solve the problem.
-Turn key to position 2. But dont start the engine.
-Floor the gas pedal for 30-40 secs.
-Release the gas pedal, step on brake and start the engine.
-Drive FORWARD (Not reverse, so make sure you are out of your garage before you attempt to do the transmission reset)

Do this every other month or when the transmission start slamming again.