Several extremely dangerous situations occured within 6 months of purchasing brand new 2015, F-150, 3.5, 4×4 ecoboost king ranch model. While driving on interstate, in rain, passing an 18 wheeler, without warning forward collision lights go off and truck begins slamming the brakes on by itself and the car behind me had to slam on his brakes to avoid a SEVERE crash. I brought truck to dealership they checked it out and said they wasnt sure why it happened and reset the computer, and put me back on the road. It continued to happen 2 or 3 more times until I realized it was only during rain, and when on side of 53′ semi truck trailers. The last time it happened was a very dangerous and unnerving experience. truck suddenly begins slamming brakes on again going thru a major city on the freeway in heavy traffic. I brought the truck into dealer, and told them i wasnt driving it until they fixed it.The first year of ownership my truck was plauged with issues. IT constantly went into limp mode while on the freeway. I was working over 3 states and the truck would go into limp mode if I accelerated to pass. I went to every ford dealership shop along the interstate for a 300 mile stretch over the next 4 years while working away from home . Most of the problems were while under warranty. finally they updated software and it stopped. This was a very dangerous problem and the dealerships werent really very helpful. My truck stayed in the dealership shop more than 60 days the first year i owned it. I bought it brand new.