I got off the hi-way thanksgiving night and noticed that the outside temp on the dash read 65 degrees when it was actually like 35 degrees. At the same time my heat went away and was getting cold air. By the time I got home 15-20 min later, the outside temp read 120 degrees, and cold heat. I looked here and saw the HCV was a common thing, so I went to the dealership and picked one up for $18.68. I then spent over 3 hours changing it as I'm no mechanic, trust me. But I did it. I burped the system and topped off the coolant. Went for a ride and cranked the climate control up to 85 and STILL got cold air. wtf. The thermostat was next on my list. I then read that the thermostat was not a common issue. My car is an 07 with 56k on it. I then read up on the outside temp sensor in the front bumper and reached under the front bumper and unplugged it. Went for a ride and the result....Hot heat!! They are related!! The outside temp sensor malfunctioning is related to the inside cabin heat being cold!! Take note of this. I'm happier than a pig in a pile of shit right now. The valve was $18, no big deal and at least thats done. I have to replace the outside temp sensor and problem fixed. I'm posting this because I didn't see any info here relating the 2. Sorry for the long wind, but wanted to be thorough.
thanks

 

If you turned auto-temp control off, would it show the same symptoms?

 

Yes, that damn ambient temp sensor caused me much aggravation. I have it ordered now online. $28.

 

Very interesting ... Thanks for posting this!

 

Yeah, the HVAC system does take inputs from the outside air temp sensor. There is a diagnostic procedure you can run to check for DTC's (a "C" or "D") related to outside air temp circuit issues. Glad you got it working

https://acurazine.com/forums/showpos...23&postcount=2

 

I am having the same issues right now. Where can I find that temperature sensor?

 

Good job!!

 

For the outside temp sensor it usually locate in front of the car. And it in front of the radiator fan

 

Great job with the troubleshooting! I am sure many people will be excited!