This issue isn't ecoboost specific but I wanted to post an interesting and frustrating problem I had with mine this past week along with the unusual solution. The issue stated when I got a message about a TPMS malfunction. I checked the tires and they were fine so continued on the camping trip we were starting. At the campground my key fob quit working. I had a spare and that one wouldn't work either. Even though both batteries going dead at the same time was unlikely, I tied new ones anyway. After a couple days troubleshooting trying everything I found the culprit. It turned out to be my girlfriends cell phone charger, one of the simple cigarette plugs that you plug a usb cable into. It was putting out so much RF that it was blocking the fob and tie pressure signals.