BMW i8 Windshield Heating Failure: Diagnosis and Solutions

Hey there! I have some experience working on hybrids and had a similar issue with my 2013 BMW i3. I feel your pain with those heating system troubles. Had my rear window heating fail completely last winter, and like yours, it was throwing error codes. Turned out the battery was heavily discharged, affecting multiple electrical systems including the heating elements. Took it to my regular workshop, and they diagnosed it with their BMW diagnostic tool. The fix wasn't cheap, cost me 290 Euro to get the battery replaced and systems recalibrated, but it solved all the heating issues completely. Could you share your specific error code and whether you're having any other electrical issues? Also, what's your battery's age and health status? This info would help me give you more targeted advice based on my experience. If you're getting both front and rear heating problems, it's likely power-related rather than just a heating element issue. Best to get it checked soon before it affects other systems.

Thanks for sharing your experience with the i3! Just had my service done last month and currently at 73739 KM. My issue seems quite different though, the battery's health is actually pretty good, and I'm not seeing any other electrical problems. The error code shows up exclusively when I try to use the windscreen heating. My theory is it might be a control module issue rather than a power problem, especially since everything else is working fine. Did your diagnostic tool show any specific module-related codes? I'd rather avoid replacing the battery if that's not the real culprit. I'm curious, after your battery replacement, did you have to do any specific calibration for the heating system, or did it just start working right away? The workshop quotes I'm getting seem really steep, so trying to gather as much info as possible before making a decision.

Hey again! Thanks for the follow-up about your i8 situation. I totally get wanting to avoid unnecessary repairs, those bills can get crazy! You know what, after reading your response, I'm actually starting to think my initial battery-focused advice might've been off the mark here. My i3's case was definitely different since I had multiple systems acting up. Your situation with just the windscreen heating and everything else working fine does point more towards a control module issue, like you suggested. When I think back, after my battery replacement, we did need specific calibration for several systems. But in your case, since the battery's good and it's just the windscreen heating, I'm leaning towards checking the control module first. The diagnostic tool I used did show module-related codes, but they were tied to the general power system failure I was experiencing. Have you noticed if the heating works intermittently at all, or is it a complete failure? In my experience working with these high-tech BMWs, isolated issues like this often come down to either the module itself or the connections to the heating elements. Much cheaper to fix than a full battery replacement! I'd suggest getting a second opinion from another workshop that specializes in BMW hybrids. Your issue seems more straightforward than what I dealt with, and shouldn't cost nearly as much as a battery replacement.

Thanks for the detailed follow-up! You've actually made me feel a bit better about the whole situation. To answer your question, it's a complete failure, not intermittent at all. The heating just doesn't respond when I turn it on, and that error code pops up immediately. Your experience really helped me think this through better. I've decided to follow your advice and look for a specialist workshop for a second opinion. You're right, since everything else is working perfectly, it wouldn't make sense to go straight for expensive repairs without checking the module and connections first. I've found a few specialized shops nearby that focus on hybrid BMWs. Going to book it in next week and will specifically ask them to check the control module and connections before anything else. Really appreciate you taking the time to share your experience and helping me narrow down the likely causes. I'll make sure to negotiate a proper diagnosis before agreeing to any major repairs. Thanks again for helping me avoid potentially unnecessary expensive repairs!