Replace BMW Key Battery It could be time to replace your battery If your BMW key isn't able to open your car or turn the engine. Fortunately, it's an easy fix. It's as easy as removing the key fob, replace the battery and gently put it back. Follow these steps https://carkeyreprogramming39672.shotblogs.com/what-you-should-be-focusing-on-improving-bmw-3-series-key-fob-44243704