Replace BMW Key Battery It could be the time to change your battery If your BMW key isn't able to open your car or turn the engine. It's simple to fix. You simply need to remove the key fob, replace the battery and gently put it back. Follow these steps https://thekeylab54013.ampblogs.com/a-step-by-step-guide-to-bmw-3-series-key-fob-66966548