I just got myself an online pass from EA, i did own a version of the game already, but the code did not work on my new xbox. i doubt this method will work if you have just bought a pre owned version of the game, but if you already have a copy of the game and you need a new online code for whatever reason, i can help you get it.
Please do not use this unless you need another code.

EA Support advisors can do it regardless of what they say.