BMW iX Won't Start: ECU Power Loss Mystery

I had a similar issue with my 2018 BMW i3. Last month, the ECU wasn't getting power, and the car wouldn't start. After checking it at the garage, they found corroded terminals at the main power connector to the ECU. The connector had some moisture damage, which caused poor contact. The fix required cleaning the terminals, replacing the damaged connector, and resealing the connection point. It wasn't a major repair, but leaving it unfixed could have led to more serious electrical problems. The technician also checked other electrical connections while they were at it. In your case, it sounds very similar to what I experienced. Since it's the power supply to the ECU, I'd check the main power connections first. These issues aren't uncommon in electric vehicles, especially if water gets where it shouldn't. I'd suggest finding a certified EV technician for this. While it might not be complex, working with EV electrical systems requires specific expertise.

Hey, that's good info about the corroded terminals! I actually went through something nearly identical with my iX last year. Curious, do you remember how much the repair set you back? Also, has everything been running smoothly since they fixed it, or have you noticed any other electrical quirks?

Hey again! Actually, I just got my i3 back from the shop last week after they fixed that Terminal 15 ignition positive issue I mentioned. The whole thing cost me 95 €, honestly not as bad as I was expecting! They found it was just a faulty cable connection to the component that needed sorting out. I'm really happy to report that since the repair, everything's been running perfectly smooth. No more starting issues or weird electrical gremlins at all. It's like having a completely different car! You know how these electrical problems can drive you crazy, but once they're properly fixed, it's such a relief. My previous experience with the corroded terminals was definitely a wake-up call about keeping an eye on these things. Now that both issues are sorted, my i3's running better than ever. If you're still having trouble with your iX, I'd definitely recommend getting it checked out, these things tend to get worse if you leave them too long. Hope this helps with your decision! Let me know if you need any other info about how the repair went down.

Thanks for sharing that detailed feedback! I bit the bullet and took my iX to a new certified EV shop yesterday. Turns out you were spot on, they found some water damage causing connection issues. The repair wasn't cheap, but at least it's sorted now. They cleaned everything up, replaced a few connectors, and did a full system check. Got the car back today and it's running like a dream. No more starting problems or warning lights. The mechanic explained everything clearly and even showed me what was wrong. Much better experience than my last garage visit! Really glad I didn't put this off any longer, these electrical gremlins can be a real pain if left unchecked. Thanks again for helping me make the decision to get it fixed properly. Sometimes you just need that push from someone who's been through something similar!