RS3 Heat Output Issue: Faulty Air Distribution Flap

I dealt with a similar issue on my 2013 RS4 a few months back, as someone with moderate car repair experience. The symptoms were nearly identical, poor temperature regulation and weak heating despite the blower motor functioning normally. After taking it to the workshop, they diagnosed a faulty cable connection to the air distribution flap actuator. The HVAC unit was working, but the compromised connection prevented proper air circulation control. The repair involved replacing the wiring harness and reconnecting the plug properly. Total cost was 95 Euro including diagnostic and labor. The most common causes for these symptoms in this model series are: Damaged wiring to air distribution components, Faulty actuator connections, Loose plug connections in the HVAC control module Before proceeding with specific advice, could you share: Have you noticed any changes in blower speed control? Does the issue occur at all temperature settings? Are you getting any specific error codes? Has there been any recent work done on the heating system? This information would help determine if your issue matches what I experienced or might be something different.

Last service was at 128000 KM. Thanks for sharing your experience. The symptoms match exactly what I am experiencing right now. No changes in blower speed control noted. The heater core seems to be functioning but with minimal output. Error code P0532 shows up on the dashboard. The HVAC unit was last checked during routine maintenance and the temperature regulation worked fine until last week. No recent work has been done on the ventilation system. The issue persists across all temperature settings, which makes me think the air distribution problem you mentioned could indeed be the culprit. Will have the wiring connections checked based on your suggestion.

Based on the error code P0532 you mentioned, this actually points to a different issue than what I initially experienced. While we both had similar symptoms with the weak heating output and temperature regulation problems, P0532 typically indicates a low pressure condition in the AC system. After learning from my repair experience, I would suggest looking at: Refrigerant pressure sensor problems, Possible refrigerant leaks in the system, Electrical connections to the pressure sensor The ventilation system issues we face in these models can be tricky since multiple components affect air distribution and temperature regulation. While my problem was resolved by fixing the flap actuator wiring, your error code suggests the root cause might be different. I recommend having a pressure test done on the system. My total diagnostic costs ran about 80 Euro when I had similar work done, though your repair costs may vary depending on what they find. The windshield fogging you might experience is another common symptom when the system pressure is off. Have you noticed any unusual sounds from the blower motor area? This could help determine if the pressure sensor issue is related to a larger system problem.

I really appreciate the detailed follow-up explanation. You make a good point about P0532 indicating a pressure-related problem rather than just a flap actuator issue. The symptoms were so similar I assumed it was the same problem, but clearly the root cause is different. To answer your question, no unusual sounds from the blower motor area. The ventilation system runs quietly as normal, just without proper temperature regulation. The windshield fogging has started becoming an issue, which matches what you mentioned about system pressure problems. I will schedule a pressure test first before having them check the wiring. Based on both your experience and the error code, it makes sense to start with the refrigerant system check. Getting the heater core working properly again is crucial with colder weather approaching. Having dealt with dashboard panel error codes before, I know these HVAC issues can be complex, one symptom can have multiple causes. The diagnostic cost estimate of 80 Euro seems reasonable. Hopefully any repairs needed will be relatively straightforward once they identify the exact pressure-related problem in the system.