I have problems with my 2009 Jetta air conditioner. It will not cool if heat soaked in a parking lot or sitting in the drive way. It will not cool until the road speed is high enough to push air through the condenser coil in the front. The vag-com shows no errors, but the radiator fan does not speed up like I think it should. Does anyone really know how the control computer works? The pressures seem reasonable and can see the pressures in the VCDS. The compressor is running and the pressure will go high when the cooling quits at low speed. I thought that there was a high pressure switch that would run the fan at hgh speed, but it looks like the system reads the pressure though an analog sensor and the fan has PWM speed control. I want to make the fan run at high speed to check the fan circuit and fan. The pressure I have seen on the VCDS is about 18 BAR. I think that the fan would run in high speed under these conditions. Does anyone know how to check the fan with the VCDS? There is a pressure sensor that is located in the same place I think since I have not yet located it. I have the Bently DVD ordered, but it is not yet here. The pressures need to get pretty high for the fans to be sped up. I have looked at the pressures with gauges, but not a the same time I had the VCDS hooked up. I have been looking for information on how the system works to little profit. Since the car cools good when moving , but takes moving at a pretty good speed to start cooling. When it is cooling it works quite well. I suspect that the fans are working as thay should, but are not being commanded to run fast enough. I would like to know how to command high speed via VCDS. This would confirm that the fans are working properly. I also need to look at the pressures via VCDS vs. This seems to be the problem---- The fans do not speed up when high head pressure would indicate insufficient cooling of the condenser coil. I have a 2000 Jetta that started growling a day ago.... I swapped it out from a donor car, but after a few minutes, the car started growling every couple of minutes, and when I checked the compressor, it seems to be short cycling in conjunction with the growling noise.... Any idea's on the issue? I'm thinking the coolant temp switch on radiator? Could the compressor be going out?... There is a pressure sensor that is located in the same place I think since I have not yet located it. I have the Bently DVD ordered, but it is not yet here. The pressures need to get pretty high for the fans to be sped up. I have looked at the pressures with gauges, but not a the same time I had the VCDS hooked up. I have been looking for information on how the system works to little profit. Since the car cools good when moving , but takes moving at a pretty good speed to start cooling. When it is cooling it works quite well. I suspect that the fans are working as thay should, but are not being commanded to run fast enough. I would like to know how to command high speed via VCDS. This would confirm that the fans are working properly. I also need to look at the pressures via VCDS vs. This seems to be the problem---- The fans do not speed up when high head pressure would indicate insufficient cooling of the condenser coil. I had exactly the same symptoms in my 2009 JSW yesterday. It was as though it refused to work on-post... What several people have found out on our year models is that the RCV on the compressor goes bad. It basically controls the flow of freon through the compressor since it doesn't technically turn on and off. You can't buy it separate from VW but there is an aftermarket version made in china available that several people have had good results with. So it is worth a shot. Many people have had good luck,including myself, with evacuating the freon, shooting an ounce or two into the system, and recharge. Others have removed the valve and cleaned it. This was gonna be my next step if mine didn't work. Before it would work, but you would just about start sweating because it took such a long time to come on. Mine seems to have failed as well. It's a 2011 JSW with manual AC. The light goes on, but no cold air. Vent fan works fine and there are no blown fuses. We use data about you for a number of purposes explained in the links below. By continuing to browse our site you agree to our use of data and cookies.
