Replace BMW Key Battery It could be time to change your battery in the event that your BMW key isn't able to open your car or turn off the engine. It's a simple fix. All you need to do is remove the cover for the key fob take it off, https://the-keylab31309.dailyblogzz.com/30731919/9-signs-that-you-re-a-bmw-3-series-key-fob-expert