I have an 03 Nissan Maxima 3.5 I just purchased a few months ago. When I first bought it I had no issues. It was sitting for a while but I have no idea how long. After I started driving it, I noticed every time I went to take off in it it wouldn’t change gears and the SLIP and TCS light was on. Well after a few miles of driving it or letting it idle for approximately 15-20 minutes, it would beep inside 3 times then it would change gears. Then a couple times of it doing this I noticed that also my power windows, locks, auto headlamps, heated seats, cruise, sunroof wouldn’t work until It done the beeping 3 times. Then after it would beep those 3 times everything would come on and work. Anybody have any idea of what it could be?? ECM? BCM? SECU?