I need help with my 4l60e! When taking off from dead stop it shifts fine from 1 to 2 but then the 3rd to 2nd downshift soleniod goes dead and the car falls on its face and some times even sounds like it is misfiring then it takes off and puts you back in the seat. I was told that the 3rd to 2nd downshift soleniod should always be on except when making a 3rd to 2nd downshift. please help!!!!