BMW iX1 Won't Start: Terminal 15 Power Supply Mystery

Hey there! I had a similar issue with my 2020 BMW i3. I have some basic experience working on EVs, but nothing too advanced. My car also wouldn't start and showed similar error messages. Turned out to be a faulty cable connection to the control unit. Took it to my regular workshop and they diagnosed it pretty quickly. The technician found a loose connection that was interrupting the power supply. Total repair cost was 95 Euro, mostly labor since they just needed to fix and secure the connection properly. What's your exact model year and have you noticed any other symptoms before this started happening? Also, are you getting any specific error codes? This could help narrow down if it's the same issue I faced. BTW, if you have a BMW iX3, they're known to have similar electrical quirks sometimes.

Thanks for sharing your experience! My iX1 is actually quite new with only 18620 KM on it and had its last service just a month ago. Your situation does sound similar to what I'm experiencing. I'm seeing error code A45F8 on the dashboard, which wasn't there before. A bit frustrating since it's still practically a new car. Did your error messages appear suddenly, or was there any warning beforehand? I'll probably need to call my service center, but wanted to check if there's anything I should know before taking it in.

Hey again! Thanks for the additional details about your iX1. Actually, when I had my i3 issue, it was also pretty new, only about 15000 KM on the clock. The error code you're seeing (A45F8) is different from what I had, though. Mine showed B2231, but the symptoms were pretty much identical, no start, control unit issues, the whole deal. And yes, in my case, the error messages also popped up suddenly without any warning. One morning the car just wouldn't start, which sounds exactly like what you're experiencing. Since your car is so new and recently serviced, I'd definitely recommend getting it to the service center. When I took mine in, I learned that sometimes these issues can actually be related to recent service work, in my case, they found that during the previous maintenance, one of the connectors wasn't properly secured. Quick tip based on my experience, before you take it in, try to document when exactly the problem started and any patterns you might have noticed (like if it happens more after the car sits for a while or after driving). This really helped speed up the diagnosis when I took my car in. Also, since your car's new, this should definitely be covered under warranty, unlike my repair which I had to pay for since my warranty had just expired. Let me know how it goes, I'm curious if it turns out to be a similar connection issue like mine was.

Thanks so much for all the detailed info! Really helpful to hear about your experience, especially since you dealt with something so similar. I've actually started keeping notes about when it happens, just like you suggested. The issue seems most common after the car sits overnight, which makes me think you might be onto something with the connection theory. I called the service center and got an appointment for tomorrow. I mentioned the error code and your experience with the loose connection after service work, and they seemed quite interested in checking that first. You're right about the warranty, they confirmed it should be fully covered since the car's only a year old. Thanks again for taking the time to share your story and tips. It's made me feel a lot better about the situation, knowing it might just be something relatively simple like a loose connection. I'll update the forum once I find out what's actually causing the problem. Fingers crossed it's a quick fix like yours was!