VW Spacefox AC Failure Linked to Sensor Malfunction

Had the same issue on my 2017 VW Golf TSI. The temperature sensor malfunction triggered error codes and completely disabled the HVAC system. Initially thought it was just a sensor, but diagnostic testing revealed the entire AC control unit was failing. The root cause was a coolant leak near the heat exchanger that damaged the control module electronics. This is a known weak point in these units. The temperature gauge would show incorrect readings before the system shut down completely. The repair required replacing both the control unit and addressing the underlying coolant leak to prevent future damage. Not a quick fix, the car was at the shop for 3 days as they needed to evacuate the AC system, replace components, and perform multiple tests to ensure proper function. This is considered a serious repair since it affects both comfort and safety systems. A malfunctioning temperature sensor can cause the engine management system to receive incorrect data, potentially leading to performance issues. Worth getting it checked soon, as continuing to run the system with a fault could cause more extensive damage to other HVAC components.

Thanks for sharing your experience. My VW had similar symptoms last year, error codes, AC problems, and engine cooling issues. The mechanic initially suspected just a bad temperature sensor, but after proper diagnostics, they found the sensor calibration was off due to a more complex issue with the cooling system. How much did your complete repair end up costing? Also wondering if youve had any related problems since getting it fixed? Really helpful to know about the control unit situation to be prepared for potential costs.

Thanks for asking about the follow-up. Since my last repair when the temperature sensor heat exchanger was diagnosed and fixed, the vehicle maintenance has been smooth with no recurring HVAC system issues. The total repair came to 980€ for the faulty air conditioning control unit replacement. This included the complete diagnosis, parts, and labor. The investment was worth it since the cooling system now works flawlessly and all error codes have cleared. The temperature gauge readings are now accurate, and I havent seen any sensor malfunction warnings in over 8 months. No more coolant leaks or climate control problems either. Getting the complete repair done, rather than just addressing individual components, proved to be the right decision for preventing future issues. Would definitely recommend getting a thorough diagnostic done, as these symptoms often point to interconnected problems in the cooling system rather than just isolated sensor failures.

Since my initial post about the VW problems, I wanted to share how things turned out. Finally took it to a different repair shop that specializes in VW cooling systems. Smart move, as they immediately spotted the real issue. Turns out the temperature sensor was actually working fine. The heat exchanger had developed a small crack, causing coolant to slowly leak onto the control module. The cooling system pressure test revealed everything. They replaced the heat exchanger, dried out and resealed the control module area, and recalibrated the temperature gauge. Total bill came to 860€, not cheap, but less than I feared after reading about others experiences. The repair took two days, and theyve even given me a 12-month warranty on the work. Been driving for three weeks now with no error codes or AC issues. The temperature readings are steady and accurate. Really glad I got a second opinion and the complete fix rather than just replacing parts one by one.