Audi S3 HVAC System Failure: Common Sensor Issues

Having some experience with sensor diagnostics, I faced a very similar issue with my 2020 Audi S4. The climate control system showed similar symptoms, and the temperature reading was completely off. After bringing it to the workshop, their diagnostic check revealed it wasnt actually the sensor itself that needed replacement, but rather a loose connection in the wiring harness connected to the climate control module. The repair involved fixing the cable connection and recalibrating the temperature control system. The total cost was 95 Euro for diagnostics and repair work. The issue hasnt returned since the fix, and the automatic climate control is working perfectly now. However, to provide more specific guidance for your case, could you share: 1. What exact error code is showing up? 2. Does the fan still work on manual settings? 3. Are you getting any temperature readings at all on the display? 4. When did the problem first start, was it gradual or sudden? These details would help determine if youre dealing with the same connection issue or if its something else in the temperature control system.

Just had my 33495 KM service done last month, and your symptoms sound exactly like what I experienced. The sensor issues turned out to be more complex than initially suspected. In my case, the temperature sensor replacement alone didnt solve it, the climate regulation module needed recalibration too. The workshop found that the main temperature control unit had a fault in the circuit board, causing incorrect readings. Total repair costs came to 450 Euro, including sensor replacement and system reprogramming. The climate system now works flawlessly. Based on the error code you mentioned, its likely youre facing a similar temperature sensor malfunction. Would recommend having both the sensor and control module checked, as fixing just one might not solve the underlying climate regulation problem.

Thanks for sharing your repair experience, it really helps validate what I suspected with these temperature sensor issues. When my S4 first showed problems, I also thought a simple sensor replacement would fix it, but like your case, it needed more comprehensive work. After your post, I had my car rechecked since the initial wiring fix wasnt holding up well. The workshop discovered the same circuit board fault in the control module that you mentioned. The temperature readings were becoming erratic again, and the climate issues started returning gradually. I ended up needing the same repair path, full sensor replacement plus module recalibration. The total came to 430 Euro, pretty close to your cost. The interesting part is how these temperature control problems seem to cascade, starting with sensor issues but revealing deeper system faults. The thorough fix has made a huge difference in the climate regulation. No more unusual temperature fluctuations or sensor malfunctions. For anyone else facing similar symptoms, its worth getting the entire control system checked rather than just focusing on individual components.

Thanks for all the detailed feedback on the HVAC sensor problems. Wanted to give a quick update on my S3 situation. Got it checked today and you were both spot on about the climate regulation system needing a complete diagnostic. The workshop confirmed multiple issues, both the temperature sensor and control module needed attention. Total repair bill came to 475 Euro, slightly more than your experiences but included a full system diagnostic and recalibration. Like you mentioned, the climate issues were interconnected, with the faulty sensor triggering wider control module problems. Really glad I didnt just replace the sensor alone. The comprehensive fix resolved all the temperature control problems. The automatic climate control now maintains perfect temperature and the AC works flawlessly. No more error codes or sensor issues showing up on the display. Thanks for helping me avoid a potentially incomplete repair that wouldnt have solved the underlying climate regulation problems. Will definitely recommend checking both sensor and control module to anyone else facing similar HVAC sensor malfunctions.