Hi, My name is*****'m happy to help you. During our conversation, I may be presenting you with different things to try, and ask you some Questions to get a better understand of the issue so I can answer your question properly. So stick with me to the end, and I am sure we should be able to get this issue resolved for you!
The BCM does control the Power windows and Power door locks. It does play a factor into Power Seats as well. If you can't communicate with it, then it's very possible it's bad. This control unit if bad, when it's replaced it has to be configured as well as all the keys for the car have to be reprogrammed. As for it's location, it is in the drivers kick panel.
That link is a image of the Bcm's location.
If you have any more questions on this, please feel free to ask.
If not, and you're satisfied with my help, please Rate me. That is how I get credit for my work. I hope I have provided you with Excellent Service.