Aright hopefully someone can help me out here. This is my first sn car so im new to the 4R70W tranny. When i test drove the car for the first time one of the first things i noticed was the O/D off light flashing, so i pressed the o/d button and the car downshifted from O/D into 3rd gear like it should ... I pressed it again and it shifted back into O/D all the while still flashing the O/D off light.. why is it down shifting when i press the O/D button if O/D was off to begin with according to the light? The car shifts firm however it holds 1st gear up to 3,200 or so rpm the first time you get in it and drive. Then shifts 1st to 2nd normal at around 2,300 rpm after stopping.Theres no slipping in the tranny at all. I have heard that the trans temp sensor could be what is causing the O/D light to flash all the time but thats about the only clue i have at this point as to what is going on. Has anyone seen or or heard of this before?