VW Taigo AC Failure Points to Compressor Issue

Having some experience with vehicle HVAC systems, I encountered a similar issue on my 2021 VW T-Cross last summer. The air conditioning repair turned out to be more complex than a simple refrigerant leak or compressor problem. The symptoms matched yours exactly, complete AC system failure, warning light, and fault code. After taking it to an authorized workshop, they diagnosed a faulty air conditioning control unit. The electronic control module had failed, causing the entire system to shut down as a safety measure. The repair involved: Full diagnostic scan, Control unit replacement, System recalibration, Function testing Total cost was 980€, but since yours is a 2023 model, this should be covered under warranty. To help provide more specific guidance, could you share: The exact error code showing up, Whether the blower motor still works when AC is off, If you notice any unusual sounds when trying to activate the system, The mileage on your Taigo, Whether any other electrical systems show issues Your description sounds very similar to my experience, but these details would help confirm if its the same root cause. Getting it checked under warranty is definitely the right move for a car this new.

Thanks for sharing those details. Mine has only 20820km from the latest service, surprised to hear about the control unit being the culprit. I hear a faint clicking noise when trying to activate the system, but nothing else happens. The blower still works fine with AC off. Just checked again and my error code is P0645, which points to the AC compressor relay circuit. No other electrical issues noticed so far. Since the automotive cooling system worked perfectly until last week, Im hoping its just the relay and not a complete AC compressor failure. Definitely planning to use the warranty. Just wanted to understand the potential issues before heading to the shop, especially after seeing reports of similar cooling system problems. Will update once I get the official diagnosis.

Interesting that you mentioned the P0645 code. When my T-Cross showed the same error last summer, I initially thought it was just the relay too. The clicking sound you described matches exactly what I experienced, its actually the system attempting to engage the auto AC compressor but failing due to the control unit not properly communicating with the relay circuit. After the repair, I learned that the relay and control unit issues are often connected in these newer VW models. The faulty control module can cause the relay to behave erratically, leading to that characteristic clicking sound. Your mileage is pretty close to what mine had when the problem occurred (I was around 22000km). While checking the car air conditioning system, the technicians also tested the relay separately, and it tested fine. The root cause was definitely the control unit miscommunicating with various components, including the relay circuit. Good call on using the warranty. These automotive cooling issues can be tricky to diagnose without proper diagnostic equipment. Once fixed, my AC has been working flawlessly for over a year now. Keep us posted on what they find, it would be helpful to confirm if these control unit failures are becoming a pattern in newer VW models.

Thanks for the input. Just got back from the dealer and wanted to close this thread with the outcome. Turns out it was indeed the control unit causing the AC system failure. The diagnostic revealed exactly what was described, the car air conditioning control module was misreading signals and causing the relay circuit error code. They replaced the control unit under warranty and reinitialized the whole auto refrigerant system. The repair took about 4 hours total including: Full system diagnosis, Control unit replacement, Refrigerant leak test, Complete system reset, Performance verification Everything works perfectly now. No more clicking sound when engaging the automotive cooling system. They mentioned seeing several similar cases recently, so its probably worth checking if anyone else with a 2023 model experiences these symptoms. Will definitely keep monitoring the AC performance, but for now the issue seems fully resolved. Thanks again for helping me understand what I was dealing with before the repair.