BMW M2 Parking Heater Failure: Common Fix Discussion

Hey there! I had a pretty similar issue with my 2020 BMW M4 last winter. The symptoms were exactly like yours, no response from the heater and that annoying warning light. Took it to my regular workshop and turns out it was a defective glow plug. The whole thing, including diagnosis and parts, cost me about 440 Euro. They had to replace the plug and reset the system. Everything's been working perfectly since then. Just to help diagnose better, does your engine have trouble starting in cold weather too? Any other warning lights showing up? Have you noticed any unusual exhaust smoke? Let me know these details and I can share more specific info from my experience with the repair process.

Thanks for sharing your experience! My M2 is sitting at 57329 KM and had its last service about 3 months ago. Actually, I have noticed some trouble starting in cold weather, but didn't connect the dots until you mentioned it. No other warning lights besides the heater one, and the exhaust seems normal. Did your workshop mention how long the repair took? I'm trying to figure out if I need to plan for a rental car. Also curious if they found any other related issues while fixing the glow plug? I'd rather address everything at once while they're in there. Really appreciate the help, this is exactly the kind of real-world experience I was hoping to learn from!

Hey again! Thanks for those extra details about your M2. Yes, the cold start issue is definitely a telltale sign, it's exactly what I experienced with my M4. The repair actually didn't take as long as I expected. My workshop got it done in about 4-5 hours, so you probably won't need a rental car if they can get you in first thing in the morning. They're pretty efficient with these BMWs. While they were working on the glow plug, they did a quick check of the whole heating system and found that my fuel lines to the heater could use a good cleaning, they had some buildup. Nothing major, but I had them do it since they were already in there. Cost me an extra 80 Euro but totally worth it for peace of mind. Given your mileage and the symptoms you're describing, it sounds very similar to what I dealt with. These auxiliary heaters are pretty reliable overall, but when they start acting up, it's usually the glow plug. The good news is that once it's fixed, it tends to stay fixed, I haven't had any issues since the repair last winter. Just make sure they do a full system reset after the repair. My mechanic said that's crucial for these newer BMWs to properly recognize the new parts. Let me know how it goes!

Thanks so much for all the detailed info! That's really helpful to know about the 4-5 hour timeframe, definitely makes me feel better about not needing a rental. And good tip about the fuel line cleaning, I'll definitely ask them to check that while they're working on it. I'm going to call my workshop tomorrow and schedule this in. I'll make sure to mention the cold start issues and ask them specifically about the glow plug, based on your experience. It's really reassuring to hear that once it's fixed, it tends to stay fixed. These BMWs can be tricky sometimes, but knowing exactly what to tell the mechanic to look for makes a huge difference. I'll definitely make sure they do that system reset you mentioned too, wouldn't have known about that if you hadn't mentioned it. Really appreciate you taking the time to share all this info. I feel much more confident about getting this sorted now that I know what I'm dealing with!