Replace BMW Key Battery It might be time to replace your battery in the event that your BMW key won't open your car or turn the engine. Fortunately, it's a simple fix. It's as easy as removing the key fob, then replace the battery, and then gently put it back. https://car-key-programming81957.blogozz.com/29510290/10-bmw-key-fobs-strategies-all-the-experts-recommend