Hello. I own a 2005 QX56. The A/C works great in summer. When the weather turns cold, the heat is mostly luke warm which means you freeze with it set on 85 degrees. If I set it on 90 degrees, then the heat works very well, but can only stand it for few minutes on that setting. Then go back to 85 degrees and you freeze again. The fan motor works well. Coolant and Freon are good (a/c will freeze you when it's hot outside). The heater control valve under the hood is working (it feels hot on both sides of the valve with the heat on, instead of hot on one side and cold on the other side). It seems like it would most likely be the air mix door actuator, but kind of doesn't make sense because the heat works normal when all the way up on 90 degrees, so I was wondering if it could be an electronic component like a faulty sensor or something. I ran the ATC self-diagnostics 2-3 times and it did not show any codes in the ambient temperature display. However, I was told if there was "If you have an air temp sensor that is sensing the interior is hotter than it actually is when you set the heat, anything but 90° it will keep cool like this. When set on 90° this bypasses the temp sensors and it blows full hot no matter what the temperature is inside the vehicle. I have seen this type of fault before and it is usually a temp sensor failure causing this needing replaced". I'm trying to avoid paying a dealer to remove the dash, etc if possible. Can anyone offer any recommendations to help pin point the problem so I can decide how to get it fixed? Any help would be greatly appreciated.
have the same problem?
Saturday, November 1st, 2014 AT 9:23 AM