BMW i4 Key Failure: Fix Costs and Expert Solutions

Hey there! I had a similar issue with my 2017 BMW iX3 last month. Initially thought it was just the key battery, but the diagnostic showed an "Affected control unit defective" error, which was related to the key recognition system. Turned out the Hall sensor was failing, but the problem was actually more complex, it was causing communication issues between the key and the car's central locking control module. Had to get both the sensor replaced and the control module reprogrammed. It was quite serious since it's a critical security component of the car. The garage had to order specific parts and use BMW-specific diagnostic tools. Took about two days to fix completely. My car had around 85,000 KM when this happened. Not something you want to mess around with at non-specialized shops, since these electrical systems are pretty complex in EVs. Would strongly suggest getting it checked at a certified BMW service center or a well-known EV specialist. Good luck with the fix!

Hey, appreciate you sharing your experience! Your situation sounds almost identical to what I'm dealing with right now. I'm curious, do you remember roughly how much you ended up paying for the whole repair job? Also, has everything been working smoothly since the fix, or have you noticed any other quirks with the key system?

Hey again! Absolutely happy to share an update! Yeah, I ended up paying exactly 1000 € to get everything sorted. I know it sounds steep, but since getting it fixed at the certified service center, everything's been working like a charm. The Hall sensor issue in the key was definitely the culprit, and they got it all sorted out properly. The best part is I haven't had a single problem with the key system since then, starts up perfectly every time! Really glad I didn't try to cut corners with a cheaper fix because these electrical systems can be super tricky. It was worth every penny to have it done right the first time. What's great is that the security system is now working exactly as it should, no more warning lights or key symbols on the dash. My iX3 recognizes the key instantly every time. If you're seeing the same symptoms, I'd say you're probably looking at a similar fix, but at least you'll know it's a proper solution that'll last. Let me know how you get on with yours!

Thanks so much for all the details! I bit the bullet and took my i4 to the certified service center today. You were spot on, it was indeed the Hall sensor causing all the trouble. What a relief to finally get it sorted! The repair cost was pretty much what you mentioned, and they even threw in a full system check. Honestly, after my last few dodgy experiences with unusual shops, this was totally worth it. The car's running perfectly now, no more frustrating key symbols or starting issues. The mechanic was super professional and walked me through everything they did. Turns out there was also a small software update needed for the key recognition system, which they included in the service. They even cleaned up some old diagnostic codes while they were at it. Really glad I asked here first, saved me from probably making another expensive mistake with a non-specialist garage. Thanks again for helping me make the right call on this one!