RSQ3 Climate Control Failure, Common Panel Issues Fixed

I had a similar issue with my Q3 (2016) last winter. Having some experience working on cars, I first suspected the HVAC system was failing completely, but it turned out to be much simpler. The problem was traced to a faulty wiring harness connection near the blower motor. The workshop found that the power supply to the climate control module was intermittent due to corroded connector pins. The temperature sensor readings were also inconsistent because of this electrical issue. The repair involved cleaning the connections and replacing a section of the wiring harness. Total cost was 95 Euro and it has worked perfectly since then. The symptoms were exactly as you describe, unresponsive controls and inconsistent heating/cooling. Before suggesting specific fixes, could you share: Which error codes your diagnostic tool showed? Does the blower motor make any noise when you adjust settings? Are you getting any temperature readings displayed on the climate control panel? This could help narrow down if you are dealing with the same root cause or if its something else in the HVAC system.

My RSQ3 is at 151813 KM and just had its annual service last month. The error codes from my diagnostic tool show P0531 and P0532 which point to the air conditioning pressure sensor circuit. The blower motor is completely silent when adjusting the climate control settings. No temperature readings show on the display at all, its completely dead most of the time. The symptoms seem to match your electronic faults description with the wiring harness. This gives me hope its not a complete climate control module failure. I will have my mechanic check the connections and power supply to the module first before replacing any major components. Thanks for the detailed explanation of your repair experience. Did your mechanic need any special tools to access the wiring connections?

Thanks for providing those details about the error codes and symptoms. Looking at these error codes and symptoms on your RSQ3, they are even more similar to what I experienced with my Q3 than I initially thought. The complete absence of blower motor noise and dead display strongly points to an electrical supply issue, just like in my case. The P0531/P0532 codes often trigger when the control module cant properly read the pressure sensor values due to wiring problems. For accessing the wiring harness in my repair, the mechanic mainly needed basic tools since most connectors are accessible once the lower dash trim is removed. The main challenge was properly testing the connections to the temperature sensor and control module without damaging the delicate pins. One key difference I notice, my blower would occasionally work intermittently, while yours seems completely non-functional. This could indicate the connection issue in your case is closer to the main power feed to the HVAC system rather than just the sensor circuits. Would recommend having your mechanic: 1. Check voltage at the main power connection to the climate control panel 2. Test continuity of the wiring harness to the pressure sensor 3. Inspect all ground connections in the HVAC circuit

The error codes and symptoms really helped pinpoint the issue. Since both the display and blower motor are completely dead, Ill have my mechanic start with checking the main power supply to the climate control panel first, then work through the electrical connectors and wiring harness. The P0531/P0532 codes make sense if its a connection problem preventing proper sensor readings. Much better to trace the electrical issues systematically than jump straight to replacing expensive components. Ill schedule the diagnostic work next week and have them focus on the power feed and ground connections to the HVAC system. At least accessing the wiring shouldnt require any specialized tools beyond what they already have. Thanks for walking through your similar repair experience. It gives me confidence we can resolve this without a complete control panel replacement.