2000 Infinity G20T wont shift at very random times. Sometimes shutting the car off and then turning it back on will correct the problem, however this method may take more than one time of shutting the car off. Seems like the car has no power, possibly stuck in a higher gear, maybe 2nd? Cold or warm doesn't seem to make a difference, Tranny fluid checked running and in Neutral, it's perfect? Any ideas what I can try?