BMW Key Fob Failure Sparks Multiple Warning Lights

Hey there! Had the same issue with my 2010 BMW 3 Series 320d last month. Got the "Battery in key empty" warning, and the keyless entry stopped working. Initially thought it was just the key battery, but turned out the key itself needed reprogramming too. The repair shop had to hook it up to their diagnostic system as the car was showing multiple error codes. In my case, the key's transponder chip had partially failed, which was causing the warning messages on the dash. They had to reprogram the key after replacing the battery. It wasn't a super serious issue, but definitely needed a proper BMW specialist to sort it out. These keys are more complex than they look, they're basically mini computers. My advice would be to take it to someone who really knows BMWs, as they'll have the right diagnostic equipment. Hope this helps.

Thanks for sharing your experience! That's really helpful as I'm facing the exact same problem. Would you mind telling me how much you ended up paying for the whole thing? Also, has everything been working fine since the repair, or have you noticed any other quirks with the key or electronics?

Hey again! Happy to help out! Yeah, just wanted to let you know everything's been working perfectly since getting it fixed. The total cost was 37 € for the whole thing, battery replacement and reprogramming included. Pretty reasonable, considering I was worried it might be something more serious! It's been about a month now, and I haven't had a single warning message pop up since. The keyless entry works like a charm again, and all those annoying dashboard warnings have completely disappeared. Honestly, the relief of having it sorted properly was worth every penny. The specialist really knew what they were doing, and they explained everything clearly. Sometimes these BMW electronics can be tricky, but this turned out to be a straightforward fix. If you're seeing the same symptoms, it's probably going to be a similar solution for your 5 Series. Let me know how it goes when you get yours fixed!

Thanks so much for the follow-up! Your experience actually convinced me to get it checked out yesterday. Funny enough, my repair turned out a bit different, and glad I didn't just try fixing it myself! Took it to a specialist mechanic who diagnosed not just a dead key battery, but also a faulty door sensor that was causing most of the warning lights. The whole thing cost me about 150 €, more than yours, but at least now everything's working perfectly. The keyless entry's back to normal, and those annoying dashboard warnings have finally disappeared. The mechanic was actually really thorough and spotted a couple of other minor issues that could've become problems later. Much better experience than my last repair shop! Sometimes paying a bit more for someone who knows what they're doing really pays off. Thanks again for your help, it really pushed me to get it sorted properly rather than just trying to replace the battery myself!