Hello all. My wife and I purchased a 2005 C6 last September, and we love it. I took it to the local Chevy dealer to have the latest reflash done for DBS back in December, and have not had any more issues with DBS so far.

Yesterday evening, we drove the Vette to pick up some dinner, and I noticed that 48 degree outside temperature air was blowing out of the upper vents. The fan was blowing quite forcefully, even though the engine was cold, and the temp control was set on both the driver and passenger to 73 degrees. This happened once before, and after disconnecting the negative battery terminal for a while, the system went back to normal operation. I disconnected the negative cable today, and after a few minutes, re-connected it. A test drive revealed that even though the temperature was set on 73 degrees, and the engine stone cold, the fan was forcefully blowing ambient 60 degree air out of the upper vents again. I had to press the AC button (last night and today) to turn off the compressor to get the upper vent air up to outside temperature, because the air was much colder with the compressor operating.

I know this is not correct, because usually the fan will blow very little air out of the vents at all until the engine is close to operating temp (when using the system for heat). I am used to slightly cooler air coming from the upper vents, and warmer air coming from the floor vents, and it is refreshing, but this is definitely not correct.

Have you guys experienced this, and what was the cause & cure?

Thanks for any help!

 

Could be one of the following:

HVAC Controller
Actuator
Ambient temperature sensor
Sunload sensor

 

I don't have a solution for you but you can perform a "soft reset" of the system by holding the following down at the same time "Front Defrost, Rear Defog and fan up buttons pressed simultaneously". This might be an easier reset than disconnecting battery cables. You mentioned 48 degree outside temp. Was that the reading on your a/c display or was it reading something else? The temp display on the HVAC panel takes it's input from the outside temp sensor located on the passenger side next to the radiator. If you are getting froggy readings from that sensor I know your a/c will do strange things.

 

Thanks guys! I disconnected the negative battery cable again, and the system began working properly. Motorhead-47, thanks for the instruction about the soft reset, this will be much easier than pulling the neg cable!

The outside temperature reading was what was displayed on the climate control LCD, and I verified it with my outdoor thermometer.

 

Please tell us where you found this information?

 

From firsthand experience with the outside temp sensor going berserk after running the car through a carwash with an undercarriage spray and from this forum...been reading this forum religiously for about 18 months now!

 

Sounds as if your problem is something other than the temp sensor that I suggested in my earlier post.

 

I asked because its the first I've ever heard of any on-board commands that can be sent with hidden key sequences other than the NAV. Any more things like this in the car that we need to know? The only one I knew about before this was the hidden keypad in the NAV as I mentioned, and how to get into it.

 

The temp sensor rest trick is the only one that I'm aware of. For what's it worth it has been mentioned on this board many times...most recently by "Talon90" in a thread just a few days ago.

http://forums.corvetteforum.com/c6-c...-reset-it.html

 

Thanks.. I missed that one obviously. I'm thinking that if Chevrolet placed one trick in there, there's probably a few more. Just have to find them.

 

This procedure worked great! My outside temp has been off since I bought the car (a week ago). It's perfect now.