2007 Ford expedition problems

My expedition is acting up real bad. On and off when I insert the key all it will do is turn acc mode on. It won't even try to turn the engine. Also, the red light around the gear it's in won't be there. Not only that, but when I stop at a gas station and put it into park, go in, come back out and put it into park or drive all it will do is reeve up. after about 5 to 40 seconds of it being in that gear it finally shifts into it. Also sometimes when I get stopped at a light and I start to go it seems like it gets stuck in limp mode and won't shift past 1st or second gear and starts redlining. It will eventually shift though. I've taken it to two ford dealerships and they can't find anything wrong. I finally took it to aamco and they ran a computer test on it and the codes for theft detection and the transmission sensor shows up. I didn't know if anyone would have a idea or if this has happened to anyone that has owned a expedition or any other car for that matter. Any help would be greatly appreciated.