Audi Q5 AC Failure Linked to Temperature Sensor

I had a similar issue with my 2013 Audi Q7 diesel. Having some experience with HVAC systems in vehicles, I initially thought it was just a sensor malfunction, but it turned out to be more complex. The symptoms matched yours exactly, warning lights, climate control system completely dead, and error codes related to the cooling system. After attempting basic troubleshooting like checking fuses and electrical connections, I took it to an independent workshop specializing in vehicle maintenance. The diagnosis revealed a defective air conditioning control unit, which was affecting multiple systems. The repair included: Replacing the control unit, System diagnosis and recalibration, Testing all HVAC components, Recharging the AC system Total cost was 980 Euro for parts and labor. The engine cooling system was also checked as these issues can be related. The fix resolved all error messages and restored full functionality to the climate control. To provide more specific advice about your case, could you share: Current mileage, Any previous AC or cooling system repairs, Specific error codes showing up, Whether the issue started suddenly or developed gradually This information would help determine if your Q5 is facing the same underlying problem.

Thanks for sharing your experience with the Q7. After last service at 167571 KM and running diagnostics, my local mechanic found that the heat exchanger was indeed malfunctioning, along with a faulty temperature sensor near the HVAC system. The error codes cleared after replacing these components, though I am still monitoring the engine cooling performance. The mechanic also discovered the sensor calibration was out of spec, likely due to age and wear. Getting this fixed at an independent shop saved considerable money compared to dealership rates. Total repair came to 750 Euro, including parts and labor. The AC is now working perfectly again. The vehicle maintenance history shows no previous cooling system issues, which made this sudden failure quite unexpected. At least the problem is now resolved and the climate control is fully operational.

Thanks for the update on your Q5 repair. Glad to hear you got it sorted for less than my Q7 repair costs. Its interesting how similar our issues were with the HVAC system malfunctions. Your mention of the temperature sensor reminds me to add that after my control unit replacement, I also had the coolant temperature gauge monitored for a few weeks to ensure the cooling system was functioning correctly. Its worth keeping an eye on these readings as sensor issues can sometimes indicate other developing problems. Since both our vehicles had similar symptoms but slightly different root causes, this really highlights how important proper diagnosis is. The fact that your heat exchanger was involved while mine was the control unit shows how these HVAC system problems can manifest similarly but require different fixes. For anyone else reading this with similar issues: always get a proper diagnosis rather than just assuming its a simple sensor problem. While sensor calibration is often the culprit, as in your case, the entire system needs proper inspection to prevent recurring issues.

The cooling system in my Q5 is working great now. Looking back, this repair taught me that temperature sensor issues and heat exchanger problems can really mess with the whole HVAC system. While the 750 Euro repair wasnt cheap, getting it done at an independent shop instead of the dealer was definitely the right call. The sensor calibration fixed most warning lights, and replacing the faulty components near the heat exchanger solved all remaining issues. No coolant leaks or temperature warnings since the repair. Pretty satisfied with how everything turned out, especially since the AC is working perfectly now. Good to know others have dealt with similar HVAC system problems in their Audis. For anyone else facing these symptoms, getting a proper diagnosis is crucial, these systems are complex and symptoms can be misleading. Thanks for all the helpful feedback that guided me toward the right fix.