how to hvac

GMC LIFE

HOW TO: USE YOUR GMC’S CLIMATE CONTROLS

Your GMC is equipped with climate controls that allow you and your passengers to stay comfortable – whether you’re braving the heat of summer or the chill of winter. This overview shows how to leverage these controls to your advantage.

red bar

Whether it’s a matter of staying cool in the heat of summer, or toasty warm during the arctic chill of winter, a climatically-controlled interior is essential to staying comfortable in your vehicle.

Fortunately, your GMC is equipped with a climate control system that allows you to do just that. Here’s how you can leverage its settings to keep you and your passengers remain as comfortable as possible while riding in your vehicle.

  • The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. See your GMC dealer for details. Click here to see all GMC destination freight charges.

  • The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. See your GMC dealer for details. Click here to see all GMC destination freight charges. Bed/Roof-Mounted Bicycle Carriers shown. Requires crossbars or Thule Rack Solution. Non-GM warranty. Warranty by Thule®. See dealer for more information.

  • Canyon’s 7000-lb rating requires available trailering package and 3.6L V-6 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Sierra's 12,500-lb rating requires Sierra Double Cab or Crew Cab Short box 2wd with 6.2L EcoTec3 V8 engine and NHT Max Trailering Package. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Trailer weight ratings are calculated assuming properly equipped vehicle, plus driver and one passenger. The weight of other optional equipment, passengers and cargo will reduce the trailer weight your vehicle can tow. See dealer for details.

  • Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Requires Double Cab with available 6.2L V-8 and Max Trailering Package. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Requires available 3.6L V6 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Sierra Denali's 9,300-lb rating requires 2wd. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Trailer weight ratings are calculated assuming properly equipped vehicle, plus driver and one passenger. The weight of other optional equipment, passengers and cargo will reduce the trailer weight your vehicle can tow. See dealer for details.

  • These maximum payload ratings are intended for comparison purposes only. Before you buy a vehicle or use it to haul people or cargo, carefully review the vehicle loading section of the Owner’s Manual and check the carrying capacity of your specific vehicle on the label on the inside of the driver’s door jamb.

  • Savana Cargo's 10,000-lb rating requires 6.0L V8 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Savana Passenger's 10,000-lb rating requires 2500 Wheel Base with 6.0L V8 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Gross Combination Weight Rating (GCWR). When properly equipped; includes weight of vehicle and trailer combination, including the weight of driver, passengers, fuel, optional equipment and cargo in the vehicle and trailer.

  • When properly equipped; includes weight of vehicle, passengers, cargo and equipment.

  • Gross Combination Weight Rating (GCWR). When properly equipped, includes weight of vehicle, passengers, cargo and equipment.

  • When properly equipped; includes weight of vehicle, passengers, cargo and equipment.

BASIC FUNCTIONS
Your climate control functions by blowing heated or cooled air through a system of ducts within the vehicle’s interior.

You can control where that air is delivered through buttons on your dashboard. For all vehicles except the 2019 GMC Sierra, an indicator light will come on once one of these modes is selected.


  • Vent: Press the button showing an icon pointing towards the upper torso, and air will be routed through vents on the dashboard/ instrument panel.
  • Floor: Press the button showing an icon pointing towards the legs and feet, and air will be primarily routed through vents placed near the floor of your vehicle
  • Bi-Level: Press the button with an icon with arrows pointing towards both the feet and torso. When lit, air is directed through both the floor and dashboard vents.
  • Defog: Press the button with an icon with arrows pointing to the windshield and arrow pointing to the legs and feet.  When lit, air is directed through both the floor and windshield defrost vents

For the Next Generation 2019 GMC Sierra, a new more flexible air distribution selection scheme allows you to pick a wider range of air delivery options using 3 buttons that are used in combination.

How It Works
The 3 Airflow Control buttons are:

  • Windshield (icon shows an arrow to the windshield): Sends airflow out of the vents near the windshield.
  • Floor (icon shows an arrow to the feet/legs): Sends airflow out of the vents at the floor.
  • Dashboard Vent (icon shows an arrow to the torso/head): The air that comes out of the dashboard vents.

You can press any or all of the 3 Airflow Control Buttons to precisely direct airflow to one or more of these areas. They act like simple on/off buttons, so you can press an unlit button, for example, and it will light up to indicate that air is flowing to that location.

If you’ve pressed multiple buttons and want to turn off airflow at one of the locations, simply press the button of the location you want shut off. That button will then be unlit.

Note: You can’t turn off airflow to all 3 locations.

WINDSHIELD DEFROSTING AND DEFOGGING
Your climate control system also incorporates important functions designed to help improve visibility through the front windshield and rear window in inclement weather.


Removing windshield frost and fog:
When your vehicle’s windshield needs to be defogged or defrosted, following these 6 steps will help clear it more efficiently:

1. Turn off the recirculation button.
2. Turn on the Quick/MAX defrost button (button has icon with Windshield and 3 squiggly arrows).
3. Set the blower to the highest setting.
4. Set the temperature to HI (auto systems) or Full Hot (manual systems).
5. Turn on the A/C.
6. Turn on the SYNC function (if available).

Maintaining a Clear Windshield
If you are concerned that your windshield may fog or you’ve just defrosted/defogged your windshield, follow these four steps to keep it clear:

1. Turn off the recirculation button.
2. Choose an airflow distribution mode that has airflow to the windshield and floor.

If your vehicle has four airflow distribution control buttons:

  • Select the single Defog button (which means air is flowing onto the windshield and floor).

If your vehicle is a 2019 GMC Sierra (has 3 airflow distribution control buttons that work in combination), then press the 3 air distribution buttons to achieve the following:

  • Windshield and Floor buttons are lit, which means air is flowing onto the windshield and floor.
  • Windshield, Floor and Panel buttons are lit, which means air is flowing onto the windshield, floor, and out of the panel outlets.

3. Set the blower to a medium setting.
4. Set the temperature a little warmer than normal.

Maintaining a Clear Rear Window
If your GMC is so equipped, you can also push the Rear Window Defogger button, which has an icon that resembles a rectangle with 3 squiggly lines through it. Doing so will heat a grid embedded into your rear window, helping melt frost, ice, or snow that may have accumulated. If your GMC is also equipped with heated side exterior mirrors, they will also be activated with the press of the Rear Window Defogger button. 



The rear window defogger only works when the ignition is switched to ON/RUN, and stays on for approximately 10 minutes after the button is pushed. Each subsequent press, the rear window defogger stays on for five minutes. The defogger also turns off if the ignition is switched to accessory or off.

AIR CONDITIONING
Pushing the A/C button on your GMC’s climate controls turns air conditioning on and off. As it is in a home or building, air conditioning can provide added comfort in warm, muggy weather by both cooling and removing humidity from the interior.



If you have an automatic climate control system, pressing the AUTO button will also turn on the A/C button. This doesn’t necessarily mean the A/C is on – it just means it’s available for the system to automatically turn it on if it’s needed.

The Recirculation button, which shows a looped arrow within a vehicle’s outline, is important to use when seeking very cool interior temperatures. Instead of continuing to draw fresh air from outside the vehicle, the recirculating feature sends already-cooled interior air back through the air conditioning system, cools it further, and sends it back into the interior. 



If you have an automatic climate control system, pressing the AUTO button will turn off the Recirculation button indicator, but the system will be controlling the vehicle recirculation automatically for best climate control performance.

TEMPERATURE CONTROL
Adjusting the temperature of the air delivered through your climate control system is easy. If you have a manual climate control system, a knob on the dashboard is labeled with a line that fades from blue on the left to red on the right. Turning that knob to the left will set the system to set cooler air. Turning the knob to the right will tell the system to deliver warmer air. If you have an automatic climate control system you should set to a reasonable living room temperature and let the auto system do the work to quickly heat or cool your vehicle. There is no need to set extreme temperatures, the system will not heat or cool to reach comfort any faster. 

FAN CONTROL
To control the fan speed of your climate control system, find the knob labeled with a fan icon. To shut off the fan entirely, either turn the fan control all the way to the left, or push the button labeled with a power icon (ф) or “ON/OFF.” If you have an automatic climate control system, pressing the AUTO button will put the fan setting into an automatic control mode and the fan will vary depending on the environmental conditions to maximize comfort at a minimum disturbance level.

AUTOMATIC CLIMATE CONTROL SYSTEM
GMC vehicles equipped with an Automatic Climate Control system can measure things like outside air temperature, solar load, interior humidity (if equipped), and your vehicle’s speed and direction. 



Using this information, the system automatically works to keep your vehicle’s interior at your preferred temperature, no matter what the weather is doing outside.

To set your preferred temperature:

  • Decide on the temperature that’s right for you. Most people choose something similar to their home thermostat setting, such as 72°F.
  • Set the climate system to that temperature.
  • Press the AUTO button. This may be found on the center stack, within the climate app on your infotainment screen or in both places. Locations vary by vehicle; your vehicle owner’s manual will provide the exact location.

The system will then adjust the fan speed, air distribution setting  and designated air temperature to quickly and efficiently reach and keep the interior of your vehicle at the temperature you set. It will balance all the parts of your vehicle’s climate control system, including temperature, fan, recirculation, A/C and where the air is  distributed.

If you adjust the temperature, AUTO mode will read that adjustment and stay active. If you adjust any of the other components, for instance, increasing or decreasing the fan, that component will switch into manual mode.

If you find the temperature is too warm or cool, make small adjustments — just 1 or 2 degrees, similarly to the way you’d adjust your home thermostat.

DUAL-ZONE CLIMATE CONTROL SETTINGS
Your GMC may be equipped with an available Dual-Zone Climate Control system, which allows both the driver and front passenger to select different temperature settings. If so, a second temperature control for the passenger is provided on the dashboard. To activate, simply adjust the secondary control to the desired temperature.



To operate the system in a single-zone mode and automatically synchronize passenger and rear zone settings to the driver’s settings, press the button marked SYNC.

REAR CLIMATE CONTROLS
Both the GMC Acadia and the GMC Yukon SUVs offer a third climate control zone for rear seat passengers, allowing those seated in the back rows of the vehicle to select their own climate control settings from controls placed on the rear of the center console.

The driver can also control the rear climate controls at any time from the front seats. On Yukon models so equipped, a set of physical buttons underneath the main climate controls provides (control) over the system. On Acadia models so equipped, a Rear Climate App can be accessed from the Infotainment home page screen (may be on the second or third page of available applications), which provides controls in the touchscreen to adjust the rear climate control system.

To prevent rear passengers from adjusting climate control settings, simply select the Rear Control Lockout button. The passenger-facing controls in rear seat can then only be adjusted via rear climate controls available in the front seat. The rear system also can be synchronized to the driver’s setting by hitting the front seat SYNC button.

LEARN MORE
If you’d like to learn more about how your GMC’s climate control system works and functions, check out the GMC Owner Center online, reference your owner’s manual, or ask your GMC dealer – they’ll be more than happy to give you a tutorial and answer any questions pertaining to your vehicle.

To learn more about other features on your GMC that can help improve your driving experience, please visit our Learning and Support page.

RELATED STORIES

TECHNOLOGY

INTRODUCING GMC MARKETPLACE

red bar

Owners with 2017 or newer GMC vehicles can now order and pay for coffee from the dash, purchase fuel without leaving the vehicle or swiping a credit card, make dinner reservations on-the go, book a hotel, and more – all from the comfort of their vehicle.

READ STORY

TECHNOLOGY

IN-VEHICLE DELIVERY: FROM AMAZON TO YOUR GMC

red bar

If you own an eligible 2015 model year or newer GMC truck or SUV with an active connected service plan, are an Amazon Prime member, and are located within an eligible delivery zip code, you can select Amazon Key In-Car Delivery on your next Amazon purchase.

READ STORY

TECHNOLOGY

MYGMC APP: SIX WAYS TO STAY CONNECTED WITH YOUR GMC

red bar

By seamlessly integrating vehicle management and connectivity features  into one application, the myGMC app is a valuable tool. Here are six  ways myGMC allows you to connect with your GMC.

READ STORY
  • The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. See your GMC dealer for details. Click here to see all GMC destination freight charges.

  • The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. See your GMC dealer for details. Click here to see all GMC destination freight charges. Bed/Roof-Mounted Bicycle Carriers shown. Requires crossbars or Thule Rack Solution. Non-GM warranty. Warranty by Thule®. See dealer for more information.

  • Canyon’s 7000-lb rating requires available trailering package and 3.6L V-6 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Sierra's 12,500-lb rating requires Sierra Double Cab or Crew Cab Short box 2wd with 6.2L EcoTec3 V8 engine and NHT Max Trailering Package. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Trailer weight ratings are calculated assuming properly equipped vehicle, plus driver and one passenger. The weight of other optional equipment, passengers and cargo will reduce the trailer weight your vehicle can tow. See dealer for details.

  • Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Requires Double Cab with available 6.2L V-8 and Max Trailering Package. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Requires available 3.6L V6 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Sierra Denali's 9,300-lb rating requires 2wd. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Trailer weight ratings are calculated assuming properly equipped vehicle, plus driver and one passenger. The weight of other optional equipment, passengers and cargo will reduce the trailer weight your vehicle can tow. See dealer for details.

  • These maximum payload ratings are intended for comparison purposes only. Before you buy a vehicle or use it to haul people or cargo, carefully review the vehicle loading section of the Owner’s Manual and check the carrying capacity of your specific vehicle on the label on the inside of the driver’s door jamb.

  • Savana Cargo's 10,000-lb rating requires 6.0L V8 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Savana Passenger's 10,000-lb rating requires 2500 Wheel Base with 6.0L V8 engine. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.

  • Gross Combination Weight Rating (GCWR). When properly equipped; includes weight of vehicle and trailer combination, including the weight of driver, passengers, fuel, optional equipment and cargo in the vehicle and trailer.

  • When properly equipped; includes weight of vehicle, passengers, cargo and equipment.

  • Gross Combination Weight Rating (GCWR). When properly equipped, includes weight of vehicle, passengers, cargo and equipment.

  • When properly equipped; includes weight of vehicle, passengers, cargo and equipment.

|