VW Arteon AC Compressor Failure: Repair Experience

I had a very similar automotive cooling issue with my 2020 VW Passat last summer. Having some experience with HVAC repairs, I first suspected a refrigerant leak, but it turned out to be more complex. The symptoms were identical, no cooling, warning lights, and the AC compressor completely unresponsive. After diagnostic testing at an authorized workshop, they found the AC control unit had failed completely. The cooling system itself was fine, but the electronic control module was preventing the compressor from engaging. The total repair came to 980€, which included: New control unit, Programming and adaptation, System testing, Refrigerant check and top-up The repair took about 4 hours to complete. Since the fix, the vehicle HVAC system has worked flawlessly. To better assist with your case, could you share: Has the AC compressor made any unusual noises before failing? What specific error codes are you getting? Did the system fail gradually or suddenly? Have you had any previous AC repairs on this car? These details would help determine if you are dealing with the same control unit issue or potentially something different.

Thanks for the detailed information about your experience. Just had my 112249km service done recently, and my situation seems quite different. In my case, the AC unit issues appeared suddenly without warning noises. The car air conditioning system just stopped working during normal driving. My error codes show P0645 and P0647, which seem to point toward an electrical problem rather than a control unit failure. Would adding these error codes help narrow down the diagnosis in your experience with the AC compressor repair?

Having gone through a similar situation with my VW Passat, those specific error codes actually help pinpoint the issue better. The P0645 and P0647 codes typically indicate an AC compressor clutch control circuit problem, which is different from the control module failure I initially experienced. Based on your codes and symptoms, this points more toward a failed AC compressor clutch relay or electrical connection issue rather than a complete compressor failure. The auto AC repair might be less expensive than my previous repair if this is the case. The sudden failure without warning sounds matches an electrical fault pattern rather than a mechanical auto refrigerant system problem. When the clutch circuit fails, it prevents the compressor from engaging, resulting in no cooling, just like your symptoms. For reference, if it is indeed the clutch circuit, repair costs typically range between 200-400€, significantly less than the control unit replacement I needed. The vehicle HVAC system should be back to normal once the electrical circuit is repaired. Have you noticed if the engine RPMs change slightly when trying to activate the AC? This could help confirm whether the compressor is attempting to engage at all.

Thank you for that information about the clutch circuit. Your AC compressor problem assessment makes sense given those specific error codes. I just had the car checked by a certified workshop and you were right, it was indeed an electrical issue, specifically a failed relay and damaged wiring harness to the compressor clutch. The repair cost came to 320€ including: New AC compressor relay, Replacement wiring harness, System diagnostic check, Labor costs The car air conditioning is working perfectly now. The repair took about 2 hours and they confirmed there were no auto refrigerant leaks or other mechanical issues with the vehicle HVAC system. They also mentioned this is a known weak point that can fail around the 100000km mark. For anyone searching with similar issues, the sudden AC failure with P0645/P0647 codes is definitely worth checking the electrical components before assuming a full compressor replacement is needed.