Audi Q3 Temp Sensor Failure Disables Key Features

Had a similar situation with an Audi Q5 2014. The outside temperature sensor malfunction initially showed as incorrect readings on the dashboard, affecting multiple systems just like your case. The temperature monitoring system serves as a primary input for several vehicle functions, which explains why your AC and winter features are affected. The sensor diagnostics revealed it wasnt the sensor itself, but a damaged wiring harness near the front bumper where the temperature sensor connects to the main system. The fix required removing the front bumper cover to access the wiring. Corrosion had damaged the connector pins and surrounding insulation. The repair involved replacing the entire sensor wiring harness and connector assembly, plus recalibrating the temperature sensor through the vehicles computer system. This is a serious issue as it affects multiple safety and comfort systems. The repair took about 4 hours in total, including diagnostic time. If your error code matches a sensor communication fault, its likely a similar wiring issue rather than a faulty sensor unit. Consider getting a second opinion from an Audi specialist who can properly diagnose whether its the wiring harness or the sensor itself. Both components need specific diagnostic equipment to properly test and calibrate after repair.

Thanks for sharing your experience with the Q5 temperature sensor issue. Your description matches my situation perfectly. The multiple system failures and error codes really had me worried. After reading about your wiring harness problem, Im convinced I might be facing something similar with my Q3. The symptoms are identical, especially with the AC and winter features not working. Did you remember the total repair cost including the sensor calibration work? Also, have you experienced any similar issues since the repair was completed?

Just got back from having this exact issue fixed on my Q5. The outside temperature sensor fault ended up being much simpler than my initial wiring harness problem. The mechanic found a loose cable connection at the sensor plug, which was causing the erratic temperature readings and system malfunctions. Total repair came to 95 Euro, which included cleaning the connector, securing the connection, and running sensor diagnostics to confirm everything was working properly. Much cheaper than my previous experience with the full harness replacement. Since the repair last month, all systems are functioning perfectly. The temperature readings are accurate, AC works flawlessly, and the winter features have returned to normal operation. The sensor calibration was spot on, and I havent seen any error codes since. Based on your Q3 symptoms, it might be worth checking the sensor connections first before assuming a complete harness replacement is needed. Sometimes these temperature sensor malfunctions can be resolved with simpler fixes.

Thanks everyone for the insights. Finally got my Q3 fixed last week and wanted to share the outcome. Took it to a certified shop specializing in sensor replacement. Turned out the temperature sensor malfunction was caused by water damage to the connector, similar to what others mentioned. The mechanic found corrosion inside the plug housing where the outside temperature sensor connects. The repair was straightforward, they cleaned the corroded terminals, applied dielectric grease, and properly sealed the connection. Total bill came to 120 Euro including sensor calibration and testing. Much better than the 500 Euro quote I got from the previous shop for a complete harness replacement. All systems are now working perfectly, accurate temperature readings, AC is back to normal, and winter features are fully functional. The sensor calibration took about 30 minutes to complete after the repair. Really glad I got a second opinion instead of rushing into an expensive fix. No error codes since the repair and temperature monitoring is spot on. Definitely recommend getting a proper diagnosis before assuming the worst with these sensor issues.