To answer your questions. No. There is no brake controller preinstalled from the factory. However, that said, the wiring is all there. The wiring is all there from the 7-pin connector at the hitch all the way to the front under the dash near the driver's left footrest. All you need to do is order yourself a brake controller (I suggest a Prodigy P3) and the pre-fabricated harness (
Brake Controller Install Harness for 2016 Toyota 4Runner | etrailer.com). Then all you need to do is mount the brake controller, connect the harness to the brake controller and then into the plug under the dash and you are good to go. I believe the required relay in the engine bay fuse block is already there. This is what I did and was very easy.