Replace BMW Key Battery If your BMW key isn't opening your car or turning on the engine, it could be 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 put it back. Follow these steps to https://carkeyreprogramming77025.blogkoo.com/a-step-by-step-guide-to-bmw-key-fobs-from-beginning-to-end-49745545