BMW i4 Key Fob Mystery: Dead Battery or Deeper Issue?

Hey there! Had the exact same issue with my 2020 BMW iX3 last month. The key fob died on me without warning, showing those annoying error messages on the dash. I initially thought it might be something major with the car's computer system, but it turned out to be just the key battery. Got it checked at the garage, they ran a full diagnostic to be safe. The funny part was, while they had it hooked up, they found that the key had been giving low battery warnings for weeks, but I'd somehow missed them. It wasn't a serious issue at all, just needed a battery replacement and quick reprogramming to sync with the car. The whole process took about 30 minutes. One tip though, if you decide to change the battery yourself, make sure you get the correct type. These newer BMWs are pretty specific about their key fob batteries, and using the wrong one can cause more problems than it solves. Hope this helps with your i4 situation.

Thanks for sharing your experience! That's really helpful and sounds exactly like what I'm dealing with. Out of curiosity, how much did they charge you for the battery replacement and reprogramming? Also, have you had any issues since getting it fixed? I'm thinking of going the DIY route, but your point about specific batteries makes me a bit nervous about messing something up.

Hey again! Just wanted to update you about the costs since you asked, I paid 37€ for the whole thing, including the battery replacement and reprogramming. And honestly, it was money well spent because I haven't had a single problem since they fixed it. The Key battery low warning completely disappeared right after the service. I totally get why you're thinking about the DIY route, I considered it too! But after seeing how the mechanics handled it with their diagnostic tools and everything, I'm glad I let the professionals do it. These new BMWs are pretty sophisticated, and while changing a battery sounds simple enough, the reprogramming bit can be tricky without the right equipment. Let me tell you, it was such a relief when everything was working properly again. The key fob works perfectly now, locks, unlocks, and all the functions are back to normal. No more annoying warning messages on the dash either! If you're still on the fence about it, I'd really recommend just getting it done at a shop. It's worth the peace of mind, and it's not as expensive as you might think.

Thanks for the detailed info! Just wanted to share what I ended up doing. After your advice, I took my car to a certified mechanic yesterday. Turns out you were spot on, it was just the key battery, but with a small twist. The technician found some corrosion on the battery contacts, which was causing the connectivity issues. The whole thing cost me slightly more than yours, they charged 45€ for cleaning the contacts, replacing the battery, and reprogramming. But honestly, I'm just relieved it wasn't anything major. The car's running perfectly now, and all those annoying warning messages are gone. Funny story though, while I was waiting, the mechanic showed me how many warning notifications my key had been sending for weeks. Just like you, I'd completely missed them! He even taught me how to check the key battery status through the car's menu for future reference. Really appreciate your help on this. Definitely made the right choice going to a professional instead of trying to fix it myself!