BMW Z4 ECU Issues: Stalling and Emergency Mode Problems

Hey there! I had a similar issue with my 2019 BMW X3 last summer. Got some experience working on cars, but I mainly trust my workshop with the complex stuff. When my engine started acting up like yours (stalling, emergency mode), I took it to my regular mechanic. Turned out the hoses were clogged, restricting proper fuel system ventilation. Had them cleaned and replaced where needed, cost me around 175 Euro. Car's been running smoothly since then. Could you share more details about when this started happening? Like, does it occur more when the engine's cold or warm? Also, any unusual sounds or smells? These details would help pinpoint if you're dealing with the same problem I had. The Z4 and X3 share quite a few components in their fuel systems, so my experience might be relevant to your case. Let me know the details, and I'll try to help further!

Thanks for sharing your experience! Mine also started acting up recently at 51516 KM. I notice it happens more frequently when the engine's warm, especially after driving for about 20 minutes. No unusual smells, but there's a slight hesitation before stalling. I had my latest service just two months ago, and everything was fine then. Your suggestion about the clogged hoses makes sense, it could explain why it's running in emergency mode. Did you notice any warning signs before it got really bad? I'm thinking of taking it to the dealership since it's still relatively new, but I'd like to have some idea of what I'm dealing with before I go in.

Hey again! Yeah, I know exactly what you mean about that hesitation before stalling, my X3 did the same thing. Actually, looking at your symptoms, they're even more similar to what I experienced than I initially thought. Before it got really bad, I did notice the car would sometimes run a bit rough when idling at traffic lights, especially on warmer days. Didn't think much of it at first, big mistake! The stalling started about a week after I first noticed the rough idle. Since your Z4 is showing these symptoms at around 51K, it's pretty much the same timeline as when my issues started. Definitely take it to the dealership while it's under warranty. With my X3, once they cleaned out those hoses and did a proper system check, they also found a small crack in one of the ventilation lines that was contributing to the problem. Quick tip though, when you take it in, make sure to mention all these symptoms, especially the warm engine stalling. My mechanic said that detail helped him diagnose it faster. The fact that yours is happening after about 20 minutes of driving is super similar to what I dealt with. Looking back, I probably could've avoided some headaches if I'd taken it in sooner. Keep us posted on what the dealership finds, really curious if it turns out to be the same issue!

Thanks so much for all the detailed info! You've honestly made me feel a lot better about this whole situation. It's really helpful to know that you experienced such similar symptoms with your X3, and that it turned out to be something fixable. I've already called the dealership and booked an appointment for tomorrow morning. I'll definitely mention everything we discussed, especially about the warm engine stalling and the timing of when it happens. You're probably right about the potential crack in the ventilation lines too, it would explain a lot of what I'm experiencing. Really glad I didn't wait any longer to deal with this. Thanks again for taking the time to share your experience. It's super valuable to hear from someone who's been through the same thing. I'll make sure to update the thread once I get it sorted out. Fingers crossed it's just those hoses and nothing more serious!