Audi S7 Blower & Climate Control System Failure Fix Guide

Had a similar issue on my 2012 Audi S5 recently. The symptoms match perfectly, complete blower motor failure combined with auto recirculation problems. The root cause was a damaged wiring harness connector at the HVAC control module. The cabin air sensor and BMW AUC-style recirculation system rely on proper electrical connections to function. When these connections fail, it typically affects multiple systems simultaneously. The repair involved: Testing the blower motor resistance, Checking all sensor connections, Replacing the main harness connector, Recalibrating the HVAC sensor system This turned out to be a serious electrical issue that required specialized diagnostic equipment. A general mechanic might miss the connection between the blower and the odor sensor system. The repair needs to be done carefully to prevent damage to the sensitive sensor array. The fix restored both the blower function and proper auto recirculation control. These issues often appear around the 150-200k km mark when connector pins start to corrode. Recommend having this diagnosed at a shop with experience in VAG electrical systems, as improper repair can damage the control module.

Thanks for sharing your experience. Sounds exactly like what happened to me. Did you remember roughly how much the repair cost in the end? Also wondering if youve had any recurring issues with the climate control system since getting it fixed? My Audi S7 cabin air sensor has been acting up again lately, but not sure if its related to the original blower motor problem.

Great news, after getting it fixed by the mechanic, my S5 has been running perfectly with no climate control issues. The auto recirculation and AUC sensor are both working as they should. The repair was surprisingly affordable at just 95 Euro to fix the faulty cable connection to the sensor component. The air conditioning sensor and all climate functions have been reliable since the fix. None of the previous symptoms have returned, the blower motor runs smoothly and the auto recirculation adjusts properly to outside conditions. Really glad I got it sorted as these sensor faults can lead to bigger problems if left unchecked. If your cabin air sensor is acting up again, I would recommend getting it checked soon. While my issue was just a loose connection, similar symptoms can sometimes indicate a failing odor sensor or control module that needs replacement.

Thanks everyone for the helpful replies. I finally took my S7 to a different shop that specializes in Audi electrical systems. Turns out the air quality sensor had completely failed, which caused the blower motor and auto recirculation issues. The cabin air sensor was also damaged due to moisture getting into the system. Total repair came to 380 Euro including parts and labor. They replaced both sensors and fixed some corroded wiring. The HVAC sensor system needed recalibration after the work was done. Been about 2 weeks now and everything is working perfectly, proper auto climate control, functioning blower motor, and the auto recirculation responds correctly to outside conditions. Definitely worth finding a specialized shop rather than going back to my regular mechanic who might have missed the root cause.