Replace BMW Key Battery If your BMW key isn't opening the doors of your car or turning on the engine, it might be the time to replace your battery. It's a simple fix. You simply need to remove the key fob, then replace the battery and gently place it back. https://the-key-lab46531.blog2news.com/30731014/10-top-mobile-apps-for-bmw-3-series-key-fob