I bought a Q4 AWD back in Oct. 2022, and I experienced the same problem with AC right away. It was not blowing cold air. And warning messages popped up on the console saying that AC system malfunctioned, and also electrical system had problem. I took it back to an Audi dealer. They had the car for around 2 weeks. First they found that refrigerant was low and they thought there was a leak. Eventually, they decided that the AC compressor was faulty. So, they replaced the AC compressor. That fixed the AC problem and it's now blowing cold air.Had to send our car back to service. AC still wasn’t blowing cold air. 4th times a charm?
Text from our service advisor -
“So we got the system adjusted again and the vent temp is blowing out at 38(f). We think there may have been an issue with our machine we are using. It's a new one but we think maybe the calibration was off on it or something. Cause the past couple times when we did the evac on the system it was saying that it pulled out even more than what the system holds. If the system gets too much in it then that can cause it to not function properly. We would like to do a couple short test drives on it if you are ok with that. We just want to make sure it's not leaking out while driving or something.”
However, I found another issue with the ventilation control (I posted this issue on another thread). If I turn on turn on the AC ventilation in a certain sequence, the fan control would not work in the manual mode. I took my car back to the dealer and they spent 5 days replacing a connector switch. But, the ventilation control problem remains. I just took the car to the same dealer and they are still working on it.