2021 GMC YUKON Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
206 Climate Controls
Manual Operation
Fan Control :Turn clockwise or
counterclockwise to increase or decrease the
fan speed. Press the knob to turn the fan
off. When off is selected, a small amount of
air may still come out of the outlets
depending on vehicle speed. If any buttons
are pressed or knobs are turned, the climate
control system will turn on and operate at
the current setting.
Press AUTO to return to automatic
operation.
Driver and Passenger Temperature Control :
The temperature can be adjusted separately
for the driver and passenger.
Turn the knob clockwise or counterclockwise
to increase or decrease the driver or
passenger temperature setting. The driver
side or passenger side temperature display
shows the temperature setting increasing or
decreasing.
SYNC : Press to link the passenger and rear
temperature setting to the driver setting.
The SYNC indicator light will turn on. When
the passenger setting is adjusted, the SYNC
indicator light will turn off. Air Delivery Mode Control :
Press
z,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.
Changing the mode cancels the automatic
operation and the system goes into manual
mode. Press AUTO to return to automatic
operation.
To change the current mode, select one or
more of the following:
z: Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed. For best results, clear all snow and ice from
the windshield before defrosting.
@:
Press to turn on recirculation. An
indicator light comes on. Air is recirculated
to quickly cool the inside of the vehicle.
It can also be used to help reduce outside
air and odors that enter the vehicle.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning on
or off. An indicator light comes on to show
that the air conditioning is enabled. If the
fan is turned off, the air conditioner will not
run. The A/C light will stay on even if the
outside temperatures are below freezing.
Rear Window Defogger
1REAR : If equipped, press to turn the
rear window defogger on or off. An indicator
light on the button comes on to show that
the rear window defogger is on.
The rear window defogger only works when
the engine is running. The defogger turns
off if the ignition is turned off or to ACC/
ACCESSORY.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Climate Controls 207
If equipped with heated outside mirrors,
press
fto turn them on or off. SeeHeated
Mirrors 030.
Caution
Using a razor blade or sharp object to
clear the inside rear window can damage
the rear window defogger. Repairs would
not be covered by the vehicle warranty.
Do not clear the inside rear window with
sharp objects.
Remote Start Climate Control Operation :
If equipped with remote start, the climate
control system may run when the vehicle is
started remotely. If equipped with heated or
ventilated seats or a heated steering wheel,
these features may come on during a
remote start. See Remote Vehicle Start 014,
Heated and Ventilated Front Seats 044, and
Heated Steering Wheel 096.
Sensors
The solar sensor, on top of the instrument
panel near the windshield, monitors the
solar heat.
The climate control system uses the sensor
information to adjust the temperature, fan
speed, recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise the
automatic climate control system may not
work properly.
Rear Climate Control System
The rear climate control system is located
on the rear of the center console storage.
The rear climate settings can be adjusted
with this system.
1. Fan Control
2. TEMP (Temperature Control)
3. Heated Rear Seats (If Equipped)
4. MODE (Air Delivery Mode Control)
5. AUTO (Automatic Operation)
If the dual automatic climate control system
rear climate control lockout feature is
locked, the rear climate control settings can
only be adjusted from the front seat.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
208 Climate Controls
Rear Climate Display
1. Rear Climate Temperature Control
2. Fan Control
3. Outside Temperature Display
4. Sync (Synchronized Temperatures)
5. Rear Control Lockout
6. Air Delivery Mode Control
7. Auto (Automatic Operation)
8. On/Off (Power)
Automatic Operation
AUTO : Press AUTO to automatically control
the temperature, air delivery, and fan speed
for rear seat passengers. A is indicated in
the display when automatic operation is
active.
If any of the rear climate control settings
are manually adjusted, full automatic
operation is canceled. Press AUTO to return
to full automatic operation.
The display only indicates climate control
functions when the system is in rear
independent mode.
Manual Operation
9: Turn clockwise or counterclockwise to
increase or decrease the fan speed. Turn
completely counterclockwise to turn the
fan/power off.
TEMP : Turn clockwise or counterclockwise
to increase or decrease the airflow
temperature into the passenger area. If the
SYNC button is pressed on the front climate
controls, the rear climate temperature is
linked to the driver temperature setting. MODE :
Press to change the direction of the
airflow in the vehicle. Repeatedly press the
button until the desired mode appears on
the display. Multiple presses will cycle
through the delivery selections.
MorL: If equipped, pressMorLto
heat the left or right outboard seat cushion.
See Heated Rear Seats 045.
Air Vents
Adjustable air vents are in the center and on
the side of the instrument panel.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Climate Controls 209
Yukon/Yukon XL is shown, Denali similar
Move the slider knobs to change the
direction of the airflow. To close the vent
adjust slider knob away from you.
Rear System Air Vents
This vehicle has four round or rectangular
air vents in the headliner above the second
and third row seats.
Press on the center vane rear edge to open
the round outlet. Use the center vane to
rotate the outlet and change the direction
of the airflow. Press on the center vane
leading edge to shut off the air flow.
Move the slider knob on rectangular vents
and rotate the outlet barrel left to right to
change the direction of the air flow and to
shut off the air flow.
Operation Tips
.Clear away any ice, snow, or leaves from
the air inlets at the base of the
windshield that could block the flow of
air into the vehicle.
.Clear snow off the hood to improve
visibility and help decrease moisture
drawn into the vehicle.
.When you enter a vehicle in cold
weather, press the fan up button to the
maximum fan level before driving. This
helps clear the intake ducts of snow and
moisture, and reduces the chance of
fogging the inside of the window.
.Keep the air path under the front seats
clear of objects to help circulate the air
inside of the vehicle more effectively.
.Use of non-GM approved hood deflectors
can adversely affect the performance of
the system. Check with your dealer
before adding equipment to the outside
of the vehicle.
Maintenance
Passenger Compartment Air Filter
The filter reduces the dust, pollen, and other
airborne irritants from outside air that is
pulled into the vehicle.
The filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule0384. To find out
what type of filter to use, see Maintenance
Replacement Parts 0394.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
210 Climate Controls
1. Open the lower glove box doorcompletely.
2. Press the sides of the glove box bininward to clear the stoppers and rotate
downward to lower the bin.
3. Unsnap dampener by pushing outwardsto fully remove the glove box bin.
4. Pull the lever (1) on the left side of thefilter door and slide left (2), then remove
the door. Remove the old filter.
5. Install the new air filter.
6. Reinstall the filter door.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional assistance is
needed.
Service
All vehicles have a label underhood that
identifies the refrigerant used in the vehicle.
The refrigerant system should only be
serviced by trained and certified technicians.
The air conditioning evaporator should never

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Climate Controls 211
be repaired or replaced by one from a
salvage vehicle. It should only be replaced
by a new evaporator to ensure proper and
safe operation.
During service, all refrigerants should be
reclaimed with proper equipment. Venting
refrigerants directly to the atmosphere is
harmful to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite, or other
health-based concerns.
The air conditioning system requires periodic
maintenance. SeeMaintenance Schedule
0 384.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
212 Driving and Operating
Driving and Operating
Driving Information
Driving for Better Fuel Economy . . . . . . . 213
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . 213
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . 214
Impaired Driving . . . . . . . . . . . . . . . . . . . . . . . 214
Control of a Vehicle . . . . . . . . . . . . . . . . . . . 214
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 215
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 216
Off-Road Driving . . . . . . . . . . . . . . . . . . . . . . . 216
Driving on Wet Roads . . . . . . . . . . . . . . . . . 219
Hill and Mountain Roads . . . . . . . . . . . . . . 220
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 221
If the Vehicle Is Stuck . . . . . . . . . . . . . . . . . . 221
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 222
Starting and Operating
New Vehicle Break-In . . . . . . . . . . . . . . . . . . 226
Ignition Positions . . . . . . . . . . . . . . . . . . . . . . 226
Starting the Engine . . . . . . . . . . . . . . . . . . . . 228
Stop/Start System . . . . . . . . . . . . . . . . . . . . . 229
Retained Accessory Power (RAP) . . . . . . . 229
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . 230
Shifting out of Park . . . . . . . . . . . . . . . . . . . 230
Parking over Things That Burn . . . . . . . . . 231
Dynamic Fuel Management . . . . . . . . . . . . 231
Extended Parking . . . . . . . . . . . . . . . . . . . . . . 231
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 231
Running the Vehicle While Parked . . . . . 232
Automatic Transmission
Automatic Transmission . . . . . . . . . . . . . . . 232
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 235
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . 235
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 236
Brakes
Electric Brake Boost . . . . . . . . . . . . . . . . . . . 240
Antilock Brake System (ABS) . . . . . . . . . . 240
Electric Parking Brake . . . . . . . . . . . . . . . . . 240
Brake Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . 242
Ride Control Systems
Traction Control/Electronic StabilityControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Hill Descent Control (HDC) . . . . . . . . . . . . 244
Driver Mode Control . . . . . . . . . . . . . . . . . . . 245
Magnetic Ride Control . . . . . . . . . . . . . . . . . 247
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . 248
Four Corner Air Suspension System . . . 248
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Adaptive Cruise Control (Advanced) . . . . 253
Driver Assistance Systems
Driver Assistance Systems . . . . . . . . . . . . . 260
Assistance Systems for Parking or Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Rear Pedestrian Alert . . . . . . . . . . . . . . . . . . 266
Assistance Systems for Driving . . . . . . . . 267
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Automatic Emergency Braking (AEB) . . . . . . . . . . . . . . . . . . . . . . . . 269
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Side Blind Zone Alert (SBZA) . . . . . . . . . . . 272
Lane Change Alert (LCA) . . . . . . . . . . . . . . . 272
Lane Keep Assist (LKA) . . . . . . . . . . . . . . . . . 275
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Recommended Fuel (5.3L Engine) . . . . . . 277
Recommended Fuel (6.2L Engine) . . . . . . 277
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 277
Fuels in Foreign Countries . . . . . . . . . . . . . 278
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . 278
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . 278
Filling a Portable Fuel Container . . . . . . . 279
Trailer Towing
General Towing Information . . . . . . . . . . 280
Driving Characteristics and Towing Tips . . . . . . . . . . . . . . . . . . . . . . . . . 280
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . 284

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 213
Towing Equipment . . . . . . . . . . . . . . . . . . . . 287
Trailer Sway Control (TSC) . . . . . . . . . . . . . 295
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . 297
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . 306
Driving Information
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here
are some driving tips to get the best fuel
economy possible:
.Set the climate controls to the desired
temperature after the engine is started,
or turn them off when not required.
.Avoid fast starts and accelerate smoothly.
.Brake gradually and avoid abrupt stops.
.Avoid idling the engine for long periods
of time.
.When road and weather conditions are
appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a single trip.
.Replace the vehicle's tires with the same
TPC Spec number molded into the tire's
sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and can
take your focus from the task of driving.
Exercise good judgment and do not let other
activities divert your attention away from
the road. Many local governments have
enacted laws regarding driver distraction.
Become familiar with the local laws in
your area.
To avoid distracted driving, keep your eyes
on the road, keep your hands on the
steering wheel, and focus your attention on
driving.
.Do not use a phone in demanding driving
situations. Use a hands-free method to
place or receive necessary phone calls.
.Watch the road. Do not read, take notes,
or look up information on phones or
other electronic devices.
.Designate a front seat passenger to
handle potential distractions.
.Become familiar with vehicle features
before driving, such as programming
favorite radio stations and adjusting
climate control and seat settings. Program
all trip information into any navigation
device prior to driving.