Replace BMW Key Battery If your BMW key isn't opening the doors of your vehicle or turning the engine, it may be time to replace your battery. It's a simple fix. It's as easy as removing the key fob, replace the battery and gently place it back. Follow these steps https://carkeyrepairs16514.wssblogs.com/30091129/why-all-the-fuss-over-bmw-key-fobs