Replace BMW Key Battery It's probably the time to change your battery if your BMW key won't open your car or turn the engine. It's an easy fix. Simply remove the key fob, replace the battery, and then gently put it back. Follow these steps and you'll be back on https://carkeyprogramming13337.theisblog.com/30253136/it-s-time-to-upgrade-your-bmw-key-fobs-options