Where is the ECM located?

My Ford expedition is running very rough, especially until it warms up, which takes about twenty something miles it seems. A gentleman tried to check my vehicle, but it wouldn't check, he said my ECM might be blown and for me to find out where it is on my SUV. I have checked YouTube Google and everything else and you're the first one that came close only you were talking about a Chevrolet can you please tell me where the ECM fuse relay module whatever it may be is located? Sorry, I don't know the leaders. You have been the most helped so far and you have an even answered my question please respond. thanks, Tracy