BMW i8: Complete AC Failure, Compressor Warning Light Issue

Hey there! I have some experience working on cars and had a very similar issue with my 2015 BMW i3. My also owns an iX, so I'm quite familiar with BMW's hybrid systems. Last summer, my AC suddenly died, no response from controls and got warning lights too. Took it to my trusted workshop, and it turned out the AC control unit was completely fried. They diagnosed it with their BMW-specific diagnostic tool and confirmed it wasn't the compressor as I initially thought. The repair cost me 980 Euro including parts and labor. Honestly, it was worth every penny because they did a thorough job and gave me a 2-year warranty on the new unit. Before I share more specific details about my repair, could you tell me if you're getting any specific error codes on the display? Also, does your AC make any unusual sounds when you try to turn it on? This would help me understand if you're dealing with the exact same issue I had.

Thanks for sharing that experience! My i8 is at 119786 KM and just had its service last month. I'm not getting any strange noises when trying to activate the AC, it's just completely unresponsive. The warning message shows "AC System Malfunction" without any specific error code. Given what you mentioned about the control unit, that might actually make more sense than my compressor theory. I'll definitely ask my mechanic to check the control unit first before diving into the compressor issue. Really appreciate the cost reference too, helps me prepare for what might be coming. Any other things I should ask them to check while they're diagnosing it?

Hey again! Yeah, what you're describing sounds exactly like what I experienced with my i3. The symptoms are spot on, especially the complete unresponsiveness without any weird noises. That's basically what happened to mine too. Since you mentioned your recent service, definitely have them check if something might have been knocked loose during that work. In my case, they also found that some electrical connections to the control unit had corroded over time, it's a common issue with these models because of their location in the car. One thing I'd definitely suggest asking them to check is the AC pressure sensor. When my control unit went bad, it also messed with the pressure sensor readings. My mechanic said these two often fail together in BMWs. In my repair, they actually replaced both just to be safe, and I haven't had any issues since. Just a heads up, if it does turn out to be the control unit, make sure they use an original BMW part. My tried an aftermarket unit in his iX to save money, and he ended up having to replace it again six months later. Sometimes paying more upfront saves money in the long run, you know? Let me know what your mechanic finds. Really curious if it's the same issue I had!

Thanks so much for all this detailed info! I wouldn't have thought about checking if anything got disturbed during the recent service, that's a really good point. And thanks for the tip about the pressure sensor and using original parts. I was actually considering asking about aftermarket options to save some money, but after hearing about your 's experience, I'll definitely stick with OEM parts. I've just scheduled an appointment with my mechanic for next week. I made sure to mention everything you brought up, the control unit, pressure sensor, and checking the electrical connections for corrosion. They seemed pretty confident they could diagnose it quickly with their diagnostic tools. I'll make sure to update you once I get it checked out. Really appreciate all your help and sharing your experience. It's saved me from going down the wrong path with the compressor theory!