BMW 3 Hybrid Warning Lights: Coolant Issue or More?

Hey there! I have some experience with cars and had a pretty similar issue with my 2021 BMW 5 Series Hybrid (I've also owned a BMW i4). I got those exact same warning lights and error codes. Took it to my regular workshop last month, and it turned out to be a faulty connection in the temperature sensor wiring. The mechanic found a damaged cable that wasn't properly connected to the sensor. Got it fixed for about 95 Euro, basically needed to replace and properly connect the wiring. Before you jump to conclusions about coolant levels (which is a good first guess), could you share: How long has this been happening? Are you noticing any coolant leaks? Does the temperature gauge show any unusual readings? This info would help determine if you're dealing with the same issue I had or something else. Let me know these details and I'll try to help further!

Thanks for your detailed response! Actually, just had my service done at 131241 KM, and this issue started right after. I'm not seeing any coolant leaks, but the temperature gauge has been acting weird, fluctuating between normal and slightly higher than usual. It's been about a week now. I was hoping it would be something simple like yours, but given the timing with my recent service, I wonder if something got disconnected during the maintenance work. The warning lights have been consistently on since then. My 3 Series has been super reliable until now, so this is pretty frustrating. Think I should get it checked out by the workshop ASAP?

Hey again! that timing with your service visit definitely raises some eyebrows. You know what? I had something similar happen after a service on my 5 Series too, and I learned the hard way that it's best to get these things checked out quickly. Since you mentioned the temperature gauge is acting up, that's actually different from what I experienced. With my wiring issue, the gauge was pretty much stuck showing high temps consistently. The fluctuating readings you're seeing could point to something else, maybe an air pocket in the cooling system that got introduced during the service, or like you said, something that wasn't reconnected properly. Given you've got a 2023 model, this should definitely be covered under warranty. I'd say don't wait on this one, my experience with BMWs is that cooling system issues can snowball pretty quickly if left unchecked. Plus, if it's related to the recent service work, they should sort it out at no cost to you. Quick tip though, before you take it in, make sure to note down exactly when the fluctuations happen (like during idle, highway driving, etc.). That really helped speed up the diagnostic process when I had my issues sorted out. Keep us posted on what they find! Always curious to learn about these quirks in our hybrids.

Thanks so much for all this helpful info! You're absolutely right about getting it checked ASAP, I've already called and booked it in for tomorrow morning. Better safe than sorry, especially with these newer hybrid systems. The tip about noting down when the fluctuations happen is really smart. I've actually started keeping track since your last message, and I've noticed it happens more when I'm idling at traffic lights. It seems to stabilize a bit during highway driving, which is kind of weird. I'll definitely update the thread once I find out what's going on. Really hoping it's just something simple that got missed during the service. At least it's still under warranty, so that's one less thing to worry about! Thanks again for taking the time to share your experience. It's super helpful to hear from someone who's dealt with similar issues, especially with these hybrid models. Really appreciate all the advice!