Replace BMW Key Battery If your BMW key isn't opening the doors of your vehicle or turning the engine, it might be the time to replace your battery. Fortunately, it's a simple fix. It's as easy as removing the key fob, replace the battery and gently place it back. Follow https://carkeyprogramming13337.theisblog.com/30362266/14-common-misconceptions-about-bmw-3-series-key-fob