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. Fortunately, it's a simple fix. You simply need to remove the key fob, then replace the battery, and then gently put it back. Follow these steps https://carkeyrepairs37440.spintheblog.com/30476515/10-bmw-key-fobs-friendly-habits-to-be-healthy