3 Door locking issue. I only bought the car a month ago but had the problem since then. The locking system doesn't work/isn't paired with the fob as it had no battery, however when I stuck a battery in it and took it to my mechanic to sync it and he tried everything but nothing worked, it wouldn't pair at all even though it was recognizing the key. Any common issues or ways to fix ? I know you can try the two keys but I only got one with my car.