VW Virtus Blower Motor Failure: AUC Sensor Alert

Having dealt with a similar issue on my VW Polo 2021, I can share my experience as someone with moderate car repair knowledge. The symptoms you describe match exactly what I encountered with the HVAC sensor system. Initially I also thought it was the blower motor, but the problem turned out to be simpler. The workshop discovered a loose connection in the wiring harness going to the climate control module. They found that the plug connecting to the cabin air sensor had corroded contacts, causing intermittent failures. The fix involved cleaning the connector and securing the wiring properly, total cost was 95€ including diagnostic time. Since then, the auto climate control and AUC sensor functions have worked flawlessly. Before taking it to the shop, you could check if the fuses related to the HVAC system are intact, though this probably wont resolve the underlying sensor fault if its similar to what I experienced. Could you provide some additional details to help narrow down the issue: Did the problem start suddenly or gradually? Does the system make any noise when you turn it on? Are there any warning lights on the dashboard? Have you noticed any other electrical issues?

Last service was at 15000km and the issue started right after. The blower completely died without warning, no gradual decline in performance. No unusual sounds or warning lights appeared. Checked all the obvious fuses but they seem fine. The auto recirculation and AUC sensor functions stopped at the same time as the blower failure. Strange thing is there are no other electrical problems anywhere else in the car. The air conditioning sensor readings still show on the display even though no air flows. Will probably need to schedule a workshop visit since even basic troubleshooting hasnt revealed anything obvious.

Interesting update. Based on the timing with your service, this sounds very similar to what happened with my Polo. Since you mentioned the air conditioning sensor readings are still displaying but with no airflow, it further confirms my suspicion about the connection issue I encountered. After my service, I discovered the technicians had disturbed the wiring while accessing other components. The AUC sensor and auto recirculation system readings can still display even with faulty connections because they operate on separate circuits from the blower motor. Quick test you can try: tap gently around the climate control module while someone operates the controls. If you get momentary operation, it likely confirms a loose connection rather than a complete sensor failure. The complete loss of the blower without warning matches the connector fault pattern. In my case, the workshop found that the service had accidentally dislodged a clip securing the main HVAC wiring harness, which then created strain on the connector pins. Given the identical symptoms and timing after service, I suggest having them check the wiring connections first before replacing any components. The diagnostic fee is typically much less than unnecessarily replacing the cabin air sensor or blower motor.

Thanks for sharing your insights about the wiring connections. The timing definitely seems suspicious since it happened right after the service. I will try the tap test you suggested before taking it in. Makes sense that the air conditioning sensor display still works while the blower doesnt, if theyre on separate circuits. I called the service center and scheduled an appointment for next week. Mentioned the problem started after their work and how the auto recirculation and climate control functions all failed simultaneously. They agreed to check the wiring harness and connectors first, focusing on areas they accessed during the recent service. Going to document everything carefully and have them verify all the HVAC system connections were properly secured after their work. Based on your experience, hopefully this turns out to be just a loose or corroded connector rather than needing to replace the entire blower motor or air quality sensor system. Thanks again for helping me narrow down the likely cause. Will update once I get it checked out.