I wanted to share how I fixed our 2015 Accord that on occasion would not start, after pressing the brake pedal down and pushing the start button nothing would happen, all accessories worked, the battery was fine but nothing, after popping the hood and slamming it shut the car would start, sometimes it would take 2 slams. Last time it happened it took about 15 slams of the hood, now I had to find the problem and fix it.
First thing I did was disconnect everything from the starter, then I ran a jumper to the main connection to the starter and another cable to the solonoid and the starter turned over fine, making me think it isn't the starter or the relay to the starter, maybe the brake pedal switch or the push button itself of a wire somewhere in the harness.
So, so my wife could at least drive it until I figured it out, I kept the jumper cable to the solonoid, I hooked up a momentary toggle switch under the steering wheel, she would just push the start button twice to get the car on and then the toggle to start it, worked like a charm. After a week or so I said screw it, I can't be bothered looking for the issue, I instead bought a nice LED momentary push button switch for 7 bucks, installed it in a blank switch spot and now she just pushed that switch after pushing the Honda start button, no more pressing on the brake pedal either.