Auto HVAC question

cornfed81 · December 10, 2015

I have an auto mode on my hvac but I prefer to manually control it. I usually turn the fan and all completely off before turning the truck off when preparing to exit out. SOMETIMES when i get back In and hit the power button for the fan it will go directly into AUTO mode. I then have to turn the fan back and adjust the temp to get it back to manual. Is this normal ? Why can't I just push the AUTO button again to turn it off ? This doesn't work for some reason. Is there something wrong or is it functioning by design. I just don't understand why it goes to auto all by itself sometimes when I turn the fan on.

scott19677 · December 10, 2015

This is just the way the new hvac system works. It drove me nuts at first because of the compressor light always being on even when the compressor is not running. I could never keep my windows from fogging up in cold damp conditions because I kept turning the compressor button off. It might take you a little while to loose the "red=warm, blue=cold,hi&lo fan" train of thought but you get used to just letting it do it's thing. Good news is there is nothing wrong with your system. Set it and forget it.

TJay74 · December 10, 2015

If you want it to work like you want don't use the Auto mode. Also if your HVAC has the newest update then the AC light will only be on when the AC compressor is engaged. The issue with the AC light being on and the compressor not running was a programming issue with in the HVAC module that was fixed in the most recent update along with how the recir door sits when not in use to try and cut down or eliminate dust in the cab that customers were complaining about.

rshad · December 11, 2015

There is a spot in setting that sets the fan to be in Low, Med, Or High. I don't know if that would helpor not.

redwngr · December 11, 2015

If you want it to work like you want don't use the Auto mode. Also if your HVAC has the newest update then the AC light will only be on when the AC compressor is engaged. The issue with the AC light being on and the compressor not running was a programming issue with in the HVAC module that was fixed in the most recent update along with how the recir door sits when not in use to try and cut down or eliminate dust in the cab that customers were complaining about.

My brand new 16 has the ac light on whenever it is enabled - even if it is not running.

rocknfire · December 11, 2015

If you want it to work like you want don't use the Auto mode. Also if your HVAC has the newest update then the AC light will only be on when the AC compressor is engaged. The issue with the AC light being on and the compressor not running was a programming issue with in the HVAC module that was fixed in the most recent update along with how the recir door sits when not in use to try and cut down or eliminate dust in the cab that customers were complaining about.

That update was more than a year ago.

chuckl1218 · December 11, 2015

That update was more than a year ago.

Yes, but don't assume all trucks have it that were built after the release date. Some calibration updates like this are installed by request only to resolve a specific issue.

cornfed81 · December 11, 2015

If you want it to work like you want don't use the Auto mode. Also if your HVAC has the newest update then the AC light will only be on when the AC compressor is engaged. The issue with the AC light being on and the compressor not running was a programming issue with in the HVAC module that was fixed in the most recent update along with how the recir door sits when not in use to try and cut down or eliminate dust in the cab that customers were complaining about.

Yes I understand to not use Auto mode if I dont want want Auto. Obviously. The problem is its going to Auto mode BY ITSELF. It only happens when first turning the fan on after the system is completely off and it only happens SOME of the time. Also why cant i push the auto button again to turn it off ? Once the AUTO light is lit you have to turn the fan down or up and manually adjust the temp to get it back off of AUTO. I cant just push the AUTO button to turn it off. It wont let me. I swear this truck has a mind of its own and pretty much tries to think for you.

ember1205 · December 11, 2015

There is a spot in setting that sets the fan to be in Low, Med, Or High. I don't know if that would helpor not.

That is a MAX setting in Auto mode. Basically, regardless of how much heating or cooling is actually required inside the truck, the fan will only run at the max speed that's set.

TJay74 · December 11, 2015

Correct, the update came out after people complained about the AC light being on/off and the compressor still being on. My issue was I would turn the AC on and then after a bit turn it off but the compressor would not turn off and would still blow cold air. I would have to turn the system off to get the compressor to turn off.

Since I had the HVAC updated my AC compressor is only on and running when the light is on. The auto mode is still quirky, sometimes I can turn the system on and it will resume from where I left it, sometimes when I turn it on it will go into auto mode even though I never ever use auto mode.

SheeB · December 13, 2015

Hmm, so guess my truck must've missed this update as my ac light is on continuously when in auto mode.

jamin87ss · December 15, 2015

Anyone have this pit #?

ember1205 · December 15, 2015

Hmm, so guess my truck must've missed this update as my ac light is on continuously when in auto mode.

As is mine, and mine was built in late June of '15.

SheeB · January 26, 2016

Anyone have this pit #?

My truck is going into the dealer tomorrow so if anyone has the TSB for this that would be great!

chuckl1218 · January 27, 2016

TJAY do you have the number for the one you are referring to? The one I had done was for HVAC working properly during remote start operations (as it does on previous years and more recent build dates). I know it fixed some other issues as well. It is PIT5240b. Is that the calibration you are referring to?