BMW M2 Overheating & Limp Mode: Coolant Crisis Solved?

I had nearly identical issues with my 2020 BMW M4 last year. The symptoms were spot on, engine temp warnings, limp mode, and those annoying check engine lights. Turned out the cooling system control module had a bad connection and was sending wrong signals to the ECU. The coolant leak was actually coming from a degraded hose connection near the control unit. The garage had to replace the control module's wiring harness and reseal several connections. They also updated the ECU software while they were at it. It wasn't a quick fix, took them about 2 days to sort everything out properly. This was definitely a serious issue that needed immediate attention to prevent engine damage. My advice would be to get it checked at a reputable BMW specialist who can properly diagnose the control unit. Those symptoms shouldn't be ignored, especially with the coolant leak. The electronic control units in these cars are pretty complex, and a bad connection can cause all sorts of weird issues.

Thanks for sharing that info! Really helpful since it sounds exactly like what I'm dealing with. The specialist I went to also replaced the control module and did some rewiring work. Quick question, do you remember roughly how much you ended up paying for the full repair? Also, has everything been running smoothly since then? Just want to make sure I won't run into any other related issues down the road.

Hey there! Happy to give you an update. After getting it fixed at the specialist, my M4 has been running like a dream, no more issues whatsoever. The control unit communication error completely disappeared after they sorted out that faulty cable connection. I got pretty lucky with the repair costs actually, only ended up paying 95 € for fixing the cable and plug connection that was causing all the trouble. Much cheaper than I originally feared! Definitely a relief since these performance cars can get pretty expensive to fix. It's been over a year now and everything's still working perfectly, no warning lights, no limp mode, nothing. The engine temp stays exactly where it should be. Just goes to show how a seemingly complex problem can sometimes have a relatively simple fix. Just make sure you keep an eye on those connections during regular maintenance and you should be good to go!

Thanks for the update! That's super reassuring. I just got my M2 back from the shop yesterday after they fixed the control module issue. You won't believe it, but my repair was more expensive, ended up paying about double what you did. The mechanic found some additional wear on the surrounding components that needed attention. But hey, at least the car's running perfectly now! No more scary warning lights or limp mode episodes. Took it for a proper drive this morning and the engine temp stayed rock steady. Such a relief to have it sorted. The mechanic also showed me what to watch out for during regular maintenance to prevent similar issues. Really appreciate you sharing your experience, helped me understand what I was dealing with and gave me confidence in the repair. Now I can finally enjoy driving my M2 again without constantly worrying about those warning lights popping up!