Honda Civic Hybrid Smoking & Stalling: Help Needed!

Hey there! I have some experience working on hybrids and went through something very similar with my 2020 Honda Insight. Those symptoms sounded really familiar to me! Initially thought it was the fuel system too, but turned out it was actually a faulty wiring harness connector near the engine control module. The symptoms were almost identical, black smoke, stalling, and that awful jerking during acceleration. My Honda Accord-owning recommended a hybrid-certified mechanic who diagnosed it pretty quickly. The fix cost me 95 Euro for the wiring harness replacement and labor. The poor connection was causing all sorts of weird electrical signals that messed with the hybrid system. Before I can share more specific advice, How many miles/kilometers on your Civic? Have you noticed any warning messages besides the check engine light? Did these issues start suddenly or gradually? Let me know these details and I can help point you in the right direction!

Thanks for your detailed response! My Civic has 257417 KM on it and had its last service about 3 months ago. The issues started pretty suddenly, like within a couple of days. And nope, no other warning lights besides the check engine one. That wiring harness issue you mentioned is really interesting, my symptoms do sound pretty similar to what you experienced. The price for your repair sounds way better than what I was worried I'd have to pay! I'll definitely look for a hybrid-certified mechanic. Did you have any problems after the repair was done? Also, how long did the whole repair process take?

Hey again! Glad I could help point you in the right direction. Yeah, after my wiring harness was fixed, my Insight's been running like a dream, no issues whatsoever! The whole repair only took about 2-3 hours, which was a huge relief. I was worried I'd be without my car for days. Given your mileage is pretty similar to what mine was when I had the problem (I was around 250,000 km), and the sudden onset of issues, I'm even more convinced it could be the same problem. The fact that there aren't any other warning lights is also similar to my situation. Just a heads up though, make sure your mechanic checks the connections thoroughly. Mine actually found some corrosion on the connector pins when they were replacing the harness. They cleaned everything up while they were in there, which probably helped prevent any future issues. Quick tip: when you take it in, ask them to scan for any stored error codes first. In my case, there were some electrical system codes that helped pinpoint the issue quickly. This saved some diagnostic time (and money!). Let me know how it goes! Always happy to share more details about my experience if you need them.

I'll respond from's perspective to complete the conversation: Thanks so much for all the extra details and tips! That's super helpful to know about the stored error codes, I'll definitely mention that to the mechanic. Really reassuring to hear your car's been running perfectly since the fix, and 2-3 hours for the repair sounds totally manageable. I actually just called a certified hybrid mechanic and booked an appointment for tomorrow morning. I mentioned the wiring harness possibility and the error code scanning you suggested. They seemed to know exactly what I was talking about! The initial diagnostic fee is reasonable too. Really appreciate you taking the time to share your experience, it's helped calm my nerves about this whole situation. I'll update the forum once I get it fixed to let everyone know what the actual issue was. Thanks again for all your help!