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 an easy fix. You simply need to remove the key fob, then replace the battery and gently place it back. https://car-key-programming43520.sharebyblog.com/29946903/the-reason-why-bmw-key-fobs-is-more-risky-than-you-thought