Hi all, My 2011 599 A/C is not blowing cold. I checked the pressures and they are within range. When I was driving the car with the recirculation button off and the temperature level set to low, I noticed very hot air coming through the vents. I suspect the A/C (cold air) is being mixed with the heater air (hot air) making the combined outcome warm air. Has anyone had this issue with their 599? I suspect the heater valve is not closing all the way. According to the WSM, the proportioning valve goes through a learning cycle whenever the battery is disconnected and if the leaning cycle fails it repeats the learning cycle whenever the cycle is cycled on. I have cycled the key several times, but the result is the same. Any ideas what the problem could be?
Yes. I hate to say it but power cycle to reset the system. That is what fixed my AC. And yes, my system appeared to be a mixing flap but it was just a reset.
Success! Disconnecting and reconnecting the battery and then going through then reconnection procedure fixed the problem! Air coming out of the vents with A/C on is 36 degrees Fahrenheit now .
Exactly and congrats. I struggled with my AC for months before I accidently ran the battery down and .... well .... it was magically fixed. I even had my system checked for leaks, evacuated, and recharged without success. THEN I figured out that it was just confused. Another hint: When you turn on the key, wait for the check light to go off before starting the car. The clutch engagement tends to be very grabby at first if you don't do that. I believe both of these are caused by a low voltage situation caused by the current draw of the starter during initial startup. It is really only an issue when the car has been sitting for a while not on the trickle charger.
Let us know if you solve the problem pursuant to the advice above. When my A/C cooling system failed on my 2010 612, the symptoms were the same as yours, but the problem and solution were more complex. If resetting the system doesn't work, I'll tell you about my problem and solution.
Kahrl, you got my interest, my 2006 612 stopped blowing cold could you share your experience? Cheers Peter.
I think ultimately you will find that the TGK valves are going bad. i had this same situation and it got progressively worse. it was about a $3K fix by FOA.... which was not so bad actually vs. taking the entire dash out.
When my A/C stopped blowing cold air, my mechanic at my request first put in new refrigerant. That didn't work. Then he checked the electrics. The computer was correctly asking for cold air, but nothing was coming out. Finally, he discovered that the system contains a sack of dessicant intended to help remove moisture from the system. The sack had ruptured, and the desiccant had been sucked into the downstream part of the cooling system. I don't know whether the desiccant was in the refrigerant circuit or in the airstream. He cleaned out the grains of desiccant from the system and that solved the problem. It took quite a while to diagnose the problem.
I had a similar problem four years ago on my 612 OTO (2008), I tried power cycling the A/C and also turning the temp from low to high which sometimes helped to reset/recalibrate or move the TGK valves. Eventually had to replace the 1 x TGK valve which kept getting stuck in open (heating position). Later the A/C ECU went crazy and started again getting different temperature air from different vents. Eventually replaced A/C ECU and all has been fine now.