Q: The car surges forward when I brake, how does it happen?

Indeed, this does sound like an annoying and a potentially dangerous problem. With the limited information given, it is difficult to determine whether your concern is mechanical or electrical. While this symptom can be the cause of both a mechanical and an electrical problem, my experience allows me to lean toward the electrical aspect to start off with. Having to hold the brakes hard to keep the vehicle from moving is a good indicator that the engine is idling high. Being in high idle while the vehicle is in gear will propel it forward or backwards depending on which gear you are in. I did a little research and discovered that your vehicle’s transmission is designed to shift into neutral when the vehicle is in gear and comes to a complete stop. If your transmission is staying in gear rather than shifting into neutral, it’s likely an electrical concern and a problem that can be fixed by flashing or reprogramming your vehicle’s computer. I would recommend taking your vehicle to your local certified dealership and have them inspect it so they can determine if you have the most up to date software.