How to troubleshoot a faulty air conditioning in an Audi A3?

I have been experiencing some issues with the air conditioning in my Audi A3. It blows out warm air even though I have adjusted the temperature setting. How can I diagnose and fix this problem?

First, check the refrigerant levels in your Audi A3. If they are low, you may need to recharge the system. If the levels are normal, it could be an issue with the AC compressor or a clogged air filter. It's best to take your car to a professional mechanic for a proper diagnosis.

Another possible cause is a faulty temperature sensor. If the sensor is not reading the correct temperature, it can cause the AC to blow out warm air. You can try resetting the sensor or replacing it if necessary.