AC in 2015 does not get very cold.

[fishnfireman]

The last few Chevy trucks I have owned-- the AC would run you out of the cab on a hot day. Not so with this one. I can leave it on high all day and never turn it down.
Took it to a dealer --they reprogramed something but it did not make any difference that I could tell.
The service manager told me the temp sensor was located inside one of the vents.. So it stands to reason it will tell the unit it is a lot colder than what the actual cab temperature is.. It does seem that I can move the air to the floor and it does get colder ... But then my feet freeze while my head sweats ..
Any thought ideas or suggestions ??

 

If it is an issue with the temp sensor...I would like to find out where it Is and either move it to the cab area or disable it and adjust it as needed ( like the old days)
Thanks-- Mike in West Texas

[15 Z71]

My 15 is same way. My 06 Silverado would freeze you out even after it was 9 years old. I took my new truck back to the dealer,and they checked it and said it was in spec of temp it should be. Does not get near as cold as my old truck. Sometimes if I turn the temp to 60 and then back to low it gets colder. Almost like it does not read setting right. Maybe try that?

[Donstar]

I also noticed a difference between my 15' SLE and my previous 09' SLE / 2000 Silversdo. I don't think the new system is faulty as the truck gets to a comfortable temperature in all weather conditions. My son lives in the Houston area and his 14 Silverado remains comfortably cool during hot days. I suspect that we may find that this is an improved system where we won't experience the extremes in hot or cold at the individual vents. It is entirely possible that your particular truck has a faulty system but I would take it to AC specialist for a second opinion before moving or disabling sensors.

[twoheeldrive]

I took my 2015 in for the same thing... while I was there I drove a new 2016... it was exactly the same... not very cold compared to my previous trucks. I went back in and told the service writer not to bother with it. Even though it's not as cold... I guess it's good enough.

 

I have the automatic air. I notice that the system cycles the recirculation on and off in auto mode and manual too. I think they have "tuned" the hvac for fuel economy.

[Silvern Sentry]

How does the defrost function work? If your defrost is not working well it may need a recharge or have a leak.

[fishnfireman]

Defrost works fine -- It has never got cold by my standards from the day it was new.. I figure the dealer would have checked that when I took it in before they tried to reprograme the thing..

[Crooks]

Are you guys changing your cabin filters?

[fishnfireman]

Yes - but not sure that would be relevant for one like mine that has done the same thing since the day it was new ?

[MikeNH]

Are the GM trucks using R1234yf yet? My Jeep does and at first it's performance seemed fine but as summer wore on I was less impressed. It still did okay but it wouldn't freeze you out like my 2011 Silverado did.

[Silvern Sentry]

Are the GM trucks using R1234yf yet? My Jeep does and at first it's performance seemed fine but as summer wore on I was less impressed. It still did okay but it wouldn't freeze you out like my 2011 Silverado did.

 

Would it not also be effected by relative humidity? It does use a compressor and liquids cannot be compressed.

 

Not sure on the science behind it but I live on the coast so very humid and my 2015 blows ICE cold after 2 summers.

 

 

Defrost works fine -- It has never got cold by my standards from the day it was new.. I figure the dealer would have checked that when I took it in before they tried to reprograme the thing..

Hmm it is probably working good as it can then. Only tip I know is your defroster uses AC always so if it is slow AC needs a charge. I do not know much about AC though as back in my day when we were doing builds using Chilton books you would get to the section about AC and it would say 'Risk of Severe Injury of Death if the AC is worked out by a non professional'.

[redwngr]

My 15 SLT would freeze you out anytime, (including those in the backseat ).

 

Same with the current 16.

[Gihan Indika]

its a common problem with these 15 or later models! there is a temp sensor behind the evaporator that measures the evaporators temp with high accuracy! the ac system designed to cut off either the high side pressure becomes 300 psi or the evaporator temp becomes 0 celcius! there is a way to overcome this but its not a genuine repair! but that makes no harm and i think it will makes you fine with the ac! the thing we have to do is fix the temp sensor from the front side of the evaporator or simply cheat the control module by providing a modified reading from the temp sensor to make the ac working continouesly untill the pressure cut off occurs!

[fishnfireman]

its a common problem with these 15 or later models! there is a temp sensor behind the evaporator that measures the evaporators temp with high accuracy! the ac system designed to cut off either the high side pressure becomes 300 psi or the evaporator temp becomes 0 celcius! there is a way to overcome this but its not a genuine repair! but that makes no harm and i think it will makes you fine with the ac! the thing we have to do is fix the temp sensor from the front side of the evaporator or simply cheat the control module by providing a modified reading from the temp sensor to make the ac working continouesly untill the pressure cut off occurs!

 

Can you give me more information as to how to "fix the temp sensor from the front side of the evaporator or simply cheat the control module by providing a modified reading from the temp sensor to make the ac working continuously until the pressure cut off occurs"!

[SouthernSilveradoGuy85]

First world problems it looks like. My '14 gets plenty cold. I read that a system with the auto feature won't get as cold as a system without the feature. The only time I've put my on "LO" is if it's really hot and humid in the cab so I use the A/C to push the hot air out, then after a few minutes I just put it back to a temp and on auto. But, I also only use the A/C if it's raining since I like driving with the windows down, even going 75 on the interstate. I guess I got used to it since my first truck/vehicle was a '86 Chevy C10 that didn't even have A/C. The only time I even complained about no A/C was if it was raining hard enough to put the windows up. That's why I said that first world problems. I guess you can say to be glad you have A/C and that it works.

[MikeNH]

 

 

Would it not also be effected by relative humidity? It does use a compressor and liquids cannot be compressed.

 

Not sure on the science behind it but I live on the coast so very humid and my 2015 blows ICE cold after 2 summers.

 

 

 

 

 

 

 

Refrigerant changes state depending on where it is in the system. It exits the compressor as a high temperature, high pressure gas, passes through the condenser up at the grill and transforms to a high temperature, high pressure liquid, passes through the thermal expansion valve (TXV) and becomes a cold, low pressure liquid, enters the evaporator in the HVAC box inside the cab, transforms to a cold, low pressure gas on the outlet where a temperature sensor for the TXV senses how cold the discharge is. If it's too cold, there is a chance liquid refrigerant would make it back to the compressor (which is bad!), so it can restrict the TXV to reduce flow. If the evap discharge is too hot, it'll open the TXV to allow more refrigerant to flow. Either way, the gaseous refrigerant leaving the evap has now warmed slightly as it has absorbed some heat and heads back to the compressor for another cycle.

 

There are a few more bits on most AC systems but that's the basic theory.

 

 

So all that said, humidity can affect AC. You often hear in weather data the term "dew point temperature". This is the temperature in which water in the air will condense on something. We see this when you have a cold beverage of your choice outside on a hot day. It gets covered in condensation. High humidity could get to the point where the evaporator can't take any more water vapor and it starts to ice up. This will make that TXV throttle back on refrigerant and limit how cold the AC will blow.

 

 

 

It's been a long time since I've worked on AC systems but I think this is all at least reasonably accurate.