Fogging windows 2010 Sierra

[latreille89]

So I read a couple of topics on this issue. I read te Tsb on it and dropped my glove compartment to see if the door to circ inside air was open or closed. Turns out my door was closed so that it was only recirculating inside air. I put the controls onto floor mode. Turned on the circ button and then put it back to defrost and the door opened to allow outside air. Just a heads up to those people that are having this issue to just go through those steps if u notice a little to much moisture. Seems to work just fine....

[2010LTZ4x4]

I wish you had posted this earlier, the exact thing happened to me tonight I got in the truck fired it up and the windshield fogged completely up.

Turned the fan speed on high to clear it up.

[latreille89]

I have a reg cab and I notice it a lot more when there is someone else in the truck with me. I drive around with my windows opened just a crack 99% of the time to ash.... bad habit... so I rarely notice my windows fogging up and then tonight I could barely see out them while driving home and I remembered reading somewhere about a fix to this. So I checked it out.. played around with the controls and figured out how to get it to get the fresh air when its being dumb.

[latreille89]

Latest TSB....

 

Bulletin No.: 11-01-38-001B

Date: July 20, 2011

Subject: Excessive Cabin Moisture / Reduced Window Clearing, Non Responsive HVAC Control (Reprogram HVAC System Control Module)

Models:

2010-2011 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2010-2011 GMC Sierra, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL

All with Manual Air Conditioning (RPO CJ3 or C67)

Vehicles Built Prior to March 14, 2011 Supercede:

This bulletin is being revised to add build date information. Please discard Corporate Bulletin Number 11-01-38-001A (Section 01 - HVAC).

Condition #1

In rare cases, some customers may comment of excessive cabin moisture or difficulty keeping the windows clear in low ambient temperatures.

Cause #1

This concern may be caused by the recirculation door being in the recirculation position while the mode is set to a floor through defrost position.

Condition #2

Some customers may comment that the HVAC temperature or mode does not change to the current HVAC control setting at start up. If the HVAC temperature or mode controls are changed, then the doors will move to the correct position. There will be no DTCs set.

Cause #2

This condition may be caused by changing the HVAC temperature or mode controls while the ignition key is turned off or immediately before turning the key off.

Correction for Condition #1 and #2

Important

DO NOT replace the HVAC control module for this concern.

Revised software has been developed to address both conditions.

Technicians are to reprogram the HVAC control module using the Service Programming System (SPS) with the latest software currently available in TIS2WEB.

When using a Tech 2® or a Multiple Diagnostic Interface (MDI) for reprogramming, ensure that it is updated with the latest software version.

During programming, the battery voltage must be maintained within the proper range of 12-15 Volts. Only use the approved Midtronics® PSC 550 Battery Maintainer (SPS Programming Support Tool EL-49642) or equivalent during programming.

[temmert1]

Going to have mine looked at also

[temmert1]

Sure enough mine was stuck on recirculate also. Switched back and forth a few times and seems to be working now...

[latreille89]

I don't know I'll bring it to the dealer for the software upgrade just yet. Maybe in the new year.

[PGDriver]

Had mine fixed last winter and not a problem since. My dealership knew all about this issue.

[04SILVRADO]

Thanx!! I'll bring it in for this. Mine is doing it too....

[Fallz]

I had the same window fogging up last night too.

 

It was because of a different reason though .....lol

[gleno97]

My truck fogs up every time i drive it!!! I'm glad for this forum. Great info all the time. My truck is goin in for the fix. I'm getting pretty discouraged every time i drive it now.

[neilbedwell]

I took my truck in 3 weeks ago for the fogging issue and had the software update applied. It seems to have helped a great deal. My dealership was completely unaware of it until I brought mine in.

[Dale_K]

I took my 2010 WT to the dealer about a week ago after reading this thread. I didn't have really bad fogging but sometimes the system blew warm air while in full A/C. If I turned the manual temp knob all the way up and then back down it would correct itself. It seemed to happen when I changed the temp dial when the truck was off - the system somehow failed to realize I had made a change and it continued to blow heat.

 

I might have had the recirc door problem too. Sometimes in really hot weather I would push the button for recirculation and couldn't hear any difference. The A/C was always super cold and in retrospect I think it might have been running in recirc mode all the time even though the flow-thru button was lit.

 

The dealer didn't argue with me or tell me they couldn't replicate it, even though it was a very intermittant problem and might not have been bad at the actual moment I was at the shop. They just did the reprogramming and it didn't take them very long either.

[Daryl LBZ]

Both my 09 and 11 do this. I'll have to see if it's doing the same thing as everyone else's.

[gleno97]

My appointment is booked at the dealer on Jan 3rd. I'll post my results.