VW Arteon AC Dead: No Airflow or Cooling

As a VW Passat 2018 2.0T owner, I encountered nearly identical symptoms last season. The complete AC failure with no airflow points to two likely issues: The blower motor failed completely, or the pressure switch detected low refrigerant and shut down the system as a safety measure. In my case, the pressure switch triggered due to a refrigerant leak at one of the AC system valves. After proper AC maintenance and diagnostic testing, it turned out one of the expansion valves had developed a significant leak. This was causing refrigerant loss and triggering the safety shutoff. The cooling system needed a full evacuation, valve replacement, and recharge to restore proper function. This is considered a serious repair since it affects the entire AC system functionality and requires specialized equipment to diagnose and fix. The repair typically involves: Full system diagnostic, Leak detection using UV dye, Evacuation of remaining refrigerant, Replacement of faulty valve, System vacuum test, Complete refrigerant recharge Given your recent disappointing shop experience, recommend finding a shop specializing in AC systems with proper diagnostic equipment to accurately identify the root cause before any repairs.

Thanks for sharing your experience. My Arteon had similar AC efficiency problems earlier this year. The temperature control issues turned out to be linked to a faulty AC relay rather than the expansion valve. After running thorough AC diagnostics, the mechanic found the relay was preventing the cooling system from engaging properly. Can you share what the final cost was for your repair? Also curious if youve had any other AC problems since getting it fixed? Would help to know if its worth exploring the relay issue with my shop vs looking at the valve replacement you mentioned. The symptoms sound really similar to what you described.

I took the Passat back to a specialized AC repair shop and their thorough AC diagnostics revealed multiple faulty valves in the cooling system. The complete repair cost 1000€, which included replacing the defective valves, evacuation, and system recharge. Since completing the temperature control system repairs six months ago, the AC has worked flawlessly without any noise or performance issues. The shop also performed a complete AC maintenance check to ensure no other components were affected. While relay issues can cause similar symptoms, the systematic failure in my case was definitely valve-related. Your mechanic seems to be on the right track with the relay diagnosis since your AC is showing different behavior patterns. Its worth letting them explore that route first, as relay repairs are typically less complex and costly than valve replacements. Just ensure they run a complete AC diagnostic test to verify the relay is the only issue before proceeding with repairs. This prevents missing any underlying problems that could cause future cooling system failures.

Here's my follow-up with the mechanic about my AC problems. The blower motor started working again after they replaced the relay switch, which cost 250€ including labor and AC diagnostics. The mechanic tested the temperature control system thoroughly to make sure no other components were causing problems. The shop confirmed the relay was preventing power from reaching the AC components, explaining why nothing worked when I turned on the system. They also did a pressure test to verify there weren't any refrigerant leaks that could cause issues later. It's been running perfectly for the past two weeks, cold air flows strongly and the temperature control works as expected. Really glad I didn't need the more extensive valve work you had done. The AC maintenance they performed should help prevent similar failures going forward. This experience taught me to get proper AC diagnostics done before assuming the worst. While valve issues are common, sometimes it's just a simple electrical component causing the whole system to fail.