Audi S6 HVAC Temperature Control Failure | Sensor Alert

Experienced the same climate regulation problems on my 2018 S4. The temperature control failure combined with AC issues typically points to a faulty HVAC sensor or damaged wiring harness. In my case, the diagnostic revealed corroded connections at the ambient temperature sensor, causing the entire climate control system to malfunction. The main control unit received incorrect temperature readings, triggering the error code and shutting down automatic functions. The repair required: Full system diagnostic, Replacement of the temperature sensor, Rewiring of the connector assembly, Recalibration of the climate control unit This was a significant repair that took several hours, as accessing the components meant removing parts of the dashboard. The sensor issues affected multiple systems, not just the AC, making it crucial to address promptly. Given the symptoms you describe, suggest having the temperature sensors tested first. A proper diagnostic will reveal if its the sensor itself or related wiring causing your climate issues. These problems rarely resolve themselves and can affect other electrical systems if left unchecked.

Thanks for sharing your experience. I had nearly identical sensor issues with my 2020 S6 last winter. The sensor diagnostics pointed to the same temperature sensor failure you mentioned. Just curious, what was your total repair cost? Mine seemed steep at 780 Euro for parts and labor. Also, have you noticed any other temperature control quirks since the sensor replacement? My climate regulation has been mostly perfect, but occasionally the system still takes longer than normal to reach the set temperature.

Had my S4 fixed last week actually. The mechanic found the climate regulation problem was indeed caused by a faulty interior temperature sensor, but the fix was much simpler than yours. The issue stemmed from a loose cable connection to the sensor component rather than needing a complete sensor replacement. Total repair cost came to 95 Euro, which included diagnosing the sensor issues and repairing the connection. Much better than a full sensor replacement. Since the fix, the temperature control system has worked flawlessly with no delays or quirks in reaching the desired settings. Your higher repair cost suggests they replaced the entire sensor unit, which would explain the price difference. The delayed response you mentioned could mean the new sensor needs recalibration. Might be worth mentioning this to your mechanic, as proper climate regulation depends on accurate sensor readings.

After getting suggestions here, I took my car to a different mechanic who specializes in sensor diagnostics. The technician found multiple temperature sensor connections had deteriorated due to heat exposure. The fix required replacing two sensors and repairing the main wiring harness near the climate control unit. Total cost was 420 Euro, much more reasonable than the 780 Euro quoted at my usual shop. The repair took about 3 hours and included a full system calibration. The temperature control now works perfectly, with no delayed response issues. The AC kicks in immediately and maintains exact temperatures. Really glad I got a second opinion instead of rushing into the first repair quote. Having a technician who understood these specific sensor issues made a huge difference in both the diagnosis and final cost.