VW Tiguan Blower Dead: AUC Sensor Investigation

Had a similar issue with my VW Golf 2017 last winter. Have some experience with basic car maintenance but needed professional help for this one. The symptoms matched exactly what youre describing, no airflow through vents and the climate control system was completely unresponsive. The auto recirculation feature had been acting weird for about a week before the complete failure. Took it to a workshop where they diagnosed a faulty connection in the wiring harness that connects to the blower control module. The cable insulation had worn through, causing intermittent connection issues. They replaced the damaged section and reconnected everything properly. Total cost was 95€ for the repair including labor. Would help to know: Does your blower motor make any noise at all when you adjust settings? Have you noticed any other electrical issues? Does the air conditioning sensor display any temperature readings? When did the auto recirculation last work normally? This could point to whether its a similar wiring issue or potentially something more complex with the odor sensor or other climate control components.

Last service was at 115000km and they didnt spot any issues with the climate control system. My blower makes absolutely no sound when adjusting settings. I did notice the cabin air sensor readings were inconsistent before the complete failure. No other electrical issues present. The auto recirculation worked fine until about 2 weeks ago when it started switching out of nowhere without obvious reason. Already checked the fuses but they all seem intact. The air quality sensor might need calibration but given theres no airflow at all, Im thinking the issue could be more serious than just a sensor fault. Will likely need professional diagnosis since accessing the blower motor requires removing several components. The temperature readings still display correctly on the climate control panel, just no actual air movement through the system.

Thanks for those details. Based on your symptoms, this sounds very similar to what I experienced with my Golf before getting it fixed. Since your fuses are good and theres zero blower response, Id lean toward either a failed blower motor or a wiring issue rather than an air quality sensor problem. In my case, the unusual auto recirculation switching was actually a separate issue from the blower failure, it was caused by a BMW AUC sensor giving false readings. The fact that your temperature display works but theres no air movement matches the symptoms I had before discovering the damaged wiring. The air conditioning sensor circuit can still function while the blower power circuit fails completely. A shop will need to test: 1. Blower motor resistance 2. Power supply to the motor 3. Ground connections 4. Control module function My repair involved accessing the blower assembly behind the glove box. Labor was about 2 hours since they had to remove several trim pieces to reach the wiring harness. Would definitely get it checked soon since driving without proper ventilation can lead to windshield fogging and reduced visibility. The total repair cost might be higher than my 95€ if your blower motor needs replacement rather than just wiring repair.

Based on my symptoms and the cabin air sensor readings being inconsistent before the failure, this definitely seems more like an electrical issue than mechanical. The blower behavior matches what you described, complete silence when adjusting settings and the unusual auto recirculation switching. My next step will be taking it to a shop for proper diagnostics of the blower motor and wiring. Since the temperature readings are still showing on the climate control panel but theres no air movement, it makes sense that the issue could be isolated to the blower circuit rather than the HVAC sensor system as a whole. The 2-hour labor estimate is helpful for planning. Really hoping its just a wiring harness problem like your Golf had and not a full blower motor replacement. Will schedule an appointment this week since driving without proper ventilation isnt ideal. Thanks for sharing your experience, helps narrow down where to start looking for the problem. Will update once I get the professional diagnosis and know exactly whats causing the failure.