[jbsails]

Why does the AC light come on when you hit the Auto button on the climate control. Is the AC really on or since it is in Auto mode it could just come on if the climate control needed to cool the car down? I just wanted to make sure I'm not driving around with the AC on in the winter and wasting gas.

I went back to the manual on this one and this is all that it said:
Automatic Operation
The system automatically controls the fan speed, air delivery, air conditioning and recirculation to heat or cool the vehicle to the selected temperature.
When the AUTO indicator light is on, the system is in full automatic operation.

I would think that even in Auto mode the AC light shouldn't come on unless the climate control turned the AC on. What is the point of having an on/off light if it's always on?

 

[scottyyyc]

The other purpose of the A/C is dehumidification. Many cars will turn on A/C all of the time or on auto. I believe there's another thread on this here, but that's what it boils down to.

Mods - perhaps a sticky or section relating to frequently asked tech questions?

 

[Narg]

My Traverse does the same thing. There are days it doesn't turn on though. Kinda weird, but nothing big IMHO.

 

[noncon]

Why does the AC light come on when you hit the Auto button on the climate control. Is the AC really on or since it is in Auto mode it could just come on if the climate control needed to cool the car down? I just wanted to make sure I'm not driving around with the AC on in the winter and wasting gas.

Not to worry. This isn't like the old school AC compressors, that once the AC clutch engages it bogs down the engine, thus wasting gas. Today's vehicles use variable displacement compressors. When it is hot out, they engage fully, and the engine works a little harder to spin it. Whereas in the cold, while the AC light may be on, the torque drain on the engine is minimal.

KJ

 

[mattgroh]

Seeing the AC light on when the outside temp is 10+ degrees less than the set point in the vehicle bothers me. I just discovered this phenomenon when we got a cool snap here recently. Has anyone seen any other info on this since this last post in February? Even if the AC is minimally engaged when its cold outside, it has to make a noticable difference in MPG in such a MPG sensitively tuned vehicle doesn't it?

 

[bballr4567]

The AC is always on when you have auto mode engaged. However, it doesnt mean the clutch is spinning the compressor. You can hear it kick on and off.

 

[djmodifyd]

if it is at all like my escalades that i've had....the compressor is used to dehumidify the air...not to cool it necessarily.

the compressor would turn off when it was a little below 40F outside air temp...is it colder then that where you are yet? If it gets colder than 30 and it is still running AND you are not on a defog mode...then i might worry. If you are on a defog mode it will run no matter what the temp to make sure it is blow dry air not moist air.

if it is below 40F OAT, and you are not running a defog mode...it will probably turn off.

 

[DavidPJ]

Both our RX330 and Escape turn on the AC when the Auto button is pressed.

 

[RSchleder]

Any of the cars I've owned that have the auto temp control have operated like the Terrain. When the auto is on, the a/c light will always be on too as it is a reflection of the fact that the a/c circuit is activated and the compressor will run if necessary to reach the desired temp.

 

[RetiredBuyer]

Here's a new question, I think. When I have the climate control in the automatic mode, shut off the vehicle, return and restart it I have to reset it to automatic mode. Kind of a pain as your driving away and realize you have no air working unless you press the "auto mode" again. If my 2006 Buick Lucerne was in auto mode when the car is shut off it remains in that mode at restart. Is my Terrain working right?

---------------------------------------------
2011 GMC Terrain SLT2 AWD
4 Cylinder
Gold Mist Met. w/brownstone leather interior

 

[gmiemigrad]

There is a setting in the configuration screen for the vehicle for the A/C when vehicle is started - the choices are: on, off, or last setting.

If it is set to always off - the system will not be in automatic mode when you restart - check this setting

From the owners manual under Instruments and Controls, Vehicle Personalization

Air Conditioning Mode
This will allow you to select whether or not the air conditioning comes on automatically the next time the vehicle is started. "On" means that the air conditioning will be on at start up, regardless of whether it was on or off the last time the vehicle was turned off. "Off" means the air conditioning will be off at the next start up, regardless of whether it was on or off the last time the vehicle was turned off. "Last Setting" means that when the vehicle is started, the air conditioning will resume whichever setting it was at the last time the vehicle was turned off.

Press the MENU/SEL knob when Air Conditioning Mode is highlighted. Turn the knob to highlight "On," "Off," or "Last Setting." Press the knob to confirm the selection and go back to the last menu.


To get to the settings for that (again, from the owners manual):

Entering the Personalization Menus

Turn the infotainment system on and press the CONFIG button to access the Configuration Settings menu.
Turn the MENU/SEL knob to highlight Vehicle Settings.
Press the center of the MENU/SEL knob to select the Vehicle Settings menu.
The following list of menu items will be available:

• Climate and Air Quality

• Comfort and Convenience

• Collision/Detection Systems

• Languages

• Lighting

• Power Door Locks

• Remote Lock/Unlock/Start

• Return to Factory Settings

Turn the MENU/SEL knob to highlight the menu. Press the knob to select it. Each of the menus is detailed in the following information. All of the menus may not be available. Only those tied to the features on your vehicle will be shown.

 

[Tdog]

Is there any reason not to leave the a/c personalization set to ON in cold weather?

 

[Chevrolet Customer Svc]

Here's a new question, I think. When I have the climate control in the automatic mode, shut off the vehicle, return and restart it I have to reset it to automatic mode. Kind of a pain as your driving away and realize you have no air working unless you press the "auto mode" again. If my 2006 Buick Lucerne was in auto mode when the car is shut off it remains in that mode at restart. Is my Terrain working right?

---------------------------------------------
2011 GMC Terrain SLT2 AWD
4 Cylinder
Gold Mist Met. w/brownstone leather interior

Has this issue been resolved? Please feel free to contact me as well if you have any further questions or concerns. Thank you.

Tricia, GM Customer Service.

 

[RetiredBuyer]

There is a setting in the configuration screen for the vehicle for the A/C when vehicle is started - the choices are: on, off, or last setting.

If it is set to always off - the system will not be in automatic mode when you restart - check this setting

From the owners manual under Instruments and Controls, Vehicle Personalization

Air Conditioning Mode
This will allow you to select whether or not the air conditioning comes on automatically the next time the vehicle is started. "On" means that the air conditioning will be on at start up, regardless of whether it was on or off the last time the vehicle was turned off. "Off" means the air conditioning will be off at the next start up, regardless of whether it was on or off the last time the vehicle was turned off. "Last Setting" means that when the vehicle is started, the air conditioning will resume whichever setting it was at the last time the vehicle was turned off.

Press the MENU/SEL knob when Air Conditioning Mode is highlighted. Turn the knob to highlight "On," "Off," or "Last Setting." Press the knob to confirm the selection and go back to the last menu.


To get to the settings for that (again, from the owners manual):

Entering the Personalization Menus

Turn the infotainment system on and press the CONFIG button to access the Configuration Settings menu.
Turn the MENU/SEL knob to highlight Vehicle Settings.
Press the center of the MENU/SEL knob to select the Vehicle Settings menu.
The following list of menu items will be available:

• Climate and Air Quality

• Comfort and Convenience

• Collision/Detection Systems

• Languages

• Lighting

• Power Door Locks

• Remote Lock/Unlock/Start

• Return to Factory Settings

Turn the MENU/SEL knob to highlight the menu. Press the knob to select it. Each of the menus is detailed in the following information. All of the menus may not be available. Only those tied to the features on your vehicle will be shown.

Thank you.....DUH. :-[ Now that you outlined it I do recall seeing that setting to leave it as "last setting". I looked and looked in the manual and while I'm sure it explains it somewhere I couldn't come up with the answer.......I'll change this setting. Thanks again

 

[Mucksiegooma]

I have a 2015 Chevy Equinox LTZ. When it push the Auto button for the Heater/AC the A/C light comes on. I took a road trip the other day, about 80 miles, and I noticed the MPG was lower than normal. On the way home, I filled the tank and turned off the Auto, the MPG per gallon increased by about 4 MPG. I am very hesitant to use AUTO in the winter here in Northern Minnesota, as when it gets warm in vehicle, you will get a blast of cold air. Not good when the outside temp is below zero. I choose not to use AUTO in the winter months. Does anyone else share my feelings?

 

[Chas]

Re:

I believe there's a setting for something like auto-dehumidify that is causing that burst of cool air (this is different from the Auto temperature control). I can't recall what it's accurately called, but it can be selected Off in the vehicle settings menu. Try searching this forum if you need more details about this setting.

Sent from my SM-T817V using Tapatalk

 

[JayTee2014]

IT is the Auto Defog Option and this feature is ON even if Auto Climate Control is in Manual Mode. It should be in the Owners Manual about P. 5-35 for 2015. It can be TURNED OFF if Selected in the Menu shown below.

This can be found in the Vehicle Personalization Menu & Climate & Air Quality:


Auto Defog - - -

When turned on and high humidity
is detected, the climate control
system may adjust to outside air
supply and turn on the air
conditioner or the heater. The fan
speed may slightly increase to help
prevent fogging. When high
humidity is no longer detected, the
system will return to its prior
operation.
Select On or Off.

Auto Rear Defog - - -

When on, this feature turns on the
rear defogger at vehicle start when
the interior temperature is cold and
fog is likely. The auto rear defog
function can be disabled by
pressing
1
. When off, the feature
can be turned on by press

 

[JayTee2014]

I noticed also, that now that cold weather has arrived, the temperature control in Manual Mode works very well.

I also have the "Auto Defog" set to off in the Personalization Menu on the radio screen.

Wonder if this helped the second OP here?

 

[rednox301]

Speaking of cold weather, a reminder for the northern forum members.
By turning the Auto Rear Defog on in the Personal Pref. Menu you also turn on the heated mirrors.
They are on a timer so you can't forget and leave them on.
:cheers:

 

[JayTee2014]

I still leave Auto defog off in colder weather. I have had heated mirrors in the last 3 vehicles we've owned and never really needed it. Whatever snow or bit of ice that might form on the outside mirrors is usually easily brushed off. To me , not worth having the darned A/C turning on whenever Auto Defog thinks it is necessary.