GMC YUKON 2021 Owner's Manual

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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
214 Driving and Operating
.Wait until the vehicle is parked to
retrieve items that have fallen to the
floor.
.Stop or park the vehicle to tend to
children.
.Keep pets in an appropriate carrier or
restraint.
.Avoid stressful conversations while
driving, whether with a passenger or on a
cell phone.
{Warning
Taking your eyes off the road too long or
too often could cause a crash resulting in
injury or death. Focus your attention on
driving.
Refer to the infotainment section for more
information on using that system and the
navigation system, if equipped, including
pairing and using a cell phone.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The first step in driving
defensively is to wear the seat belt. See
Seat Belts 053.
.Assume that other road users
(pedestrians, bicyclists, and other drivers)
are going to be careless and make
mistakes. Anticipate what they may do
and be ready.
.Allow enough following distance between
you and the driver in front of you.
.Focus on the task of driving.
Impaired Driving
Death and injury associated with impaired
driving is a global tragedy.
{Warning
Drinking alcohol or taking drugs and then
driving is very dangerous. Your reflexes,
perceptions, attentiveness, and judgment
can be affected by even a small amount
of alcohol or drugs. You can have a
serious —or even fatal —collision if you
drive after drinking or taking drugs.
Do not drive while under the influence of
alcohol or drugs, or ride with a driver
who has been drinking or is impaired by
drugs. Find alternate transportation
home; or if you are with a group,
designate a driver who will remain sober.
Control of a Vehicle
Braking, steering, and accelerating are
important factors in helping to control a
vehicle while driving.
Braking
Braking action involves perception time and
reaction time. Deciding to push the brake
pedal is perception time. Actually doing it is
reaction time.
Average driver reaction time is about
three-quarters of a second. In that time, a
vehicle moving at 100 km/h (60 mph) travels
20 m (66 ft), which could be a lot of
distance in an emergency.
Helpful braking tips to keep in mind include:
.Keep enough distance between you and
the vehicle in front of you.
.Avoid needless heavy braking.
.Keep pace with traffic.
If the engine ever stops while the vehicle is
being driven, brake normally but do not
pump the brakes. Doing so could make the
pedal harder to push down. If the engine
stops, there will be some power brake assist
but it will be used when the brake is

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 215
applied. Once the power assist is used up, it
can take longer to stop and the brake pedal
will be harder to push.
Steering
Caution
To avoid damage to the steering system,
do not drive over curbs, parking barriers,
or similar objects at speeds greater than
3 km/h (1 mph). Use care when driving
over other objects such as lane dividers
and speed bumps. Damage caused by
misuse of the vehicle is not covered by
the vehicle warranty.
Electric Power Steering
This vehicle has electric power steering.
It does not have power steering fluid.
Regular maintenance is not required.
If power steering assist is lost due to a
system malfunction, the vehicle can be
steered, but may require increased effort.
If the steering assist is used for an extended
period of time while the vehicle is not
moving, power assist may be reduced.
If the steering wheel is turned until it
reaches the end of its travel, and is held in
that position for an extended period of time,
power steering assist may be reduced.
Normal use of the power steering assist
should return when the system cools down.
See your dealer if there is a problem.
Curve Tips
.Take curves at a reasonable speed.
.Reduce speed before entering a curve.
.Maintain a reasonable steady speed
through the curve.
.Wait until the vehicle is out of the curve
before accelerating gently into the
straightaway.
Steering in Emergencies
.There are some situations when steering
around a problem may be more effective
than braking.
.Holding both sides of the steering wheel
allows you to turn 180 degrees without
removing a hand.
.Antilock Brake System (ABS) allows
steering while braking.
Off-Road Recovery
The vehicle's right wheels can drop off the
edge of a road onto the shoulder while
driving. Follow these tips:

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
216 Driving and Operating
1. Ease off the accelerator and then,if there is nothing in the way, steer the
vehicle so that it straddles the edge of
the pavement.
2. Turn the steering wheel about one-eighth of a turn, until the right front
tire contacts the pavement edge.
3. Turn the steering wheel to go straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three control
systems:
.Braking Skid —wheels are not rolling.
.Steering or Cornering Skid —too much
speed or steering in a curve causes tires
to slip and lose cornering force.
.Acceleration Skid —too much throttle
causes the driving wheels to spin.
Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions,
and by not overdriving those conditions. But
skids are always possible.
If the vehicle starts to slide, follow these
suggestions:
.Ease your foot off the accelerator pedal
and steer the way you want the vehicle
to go. The vehicle may straighten out. Be
ready for a second skid if it occurs.
.Slow down and adjust your driving
according to weather conditions. Stopping
distance can be longer and vehicle control
can be affected when traction is reduced
by water, snow, ice, gravel, or other
material on the road. Learn to recognize
warning clues —such as enough water,
ice, or packed snow on the road to make
a mirrored surface —and slow down
when you have any doubt.
.Try to avoid sudden steering, acceleration,
or braking, including reducing vehicle
speed by shifting to a lower gear. Any
sudden changes could cause the tires to
slide.
Remember: Antilock brakes help avoid only
the braking skid.
Off-Road Driving
Four-wheel-drive vehicles can be used for
off-road driving. Vehicles without four-wheel
drive and vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR) tires must
not be driven off-road except on a level, solid surface. For contact information about
the original equipment tires, see the
warranty manual.
One of the best ways for successful off-road
driving is to control the speed.
{Warning
When driving off-road, bouncing and
quick changes in direction can easily
throw you out of position. This could
cause you to lose control and crash. You
and your passengers should always wear
seat belts.
Before Driving Off-Road
.Have all necessary maintenance and
service work completed.
.Fuel the vehicle, fill fluid levels, and check
inflation pressure in all tires, including the
spare, if equipped.
.Read all the information about
four-wheel-drive vehicles in this manual.
.Know the local laws that apply to off-road
driving.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 217
Loading the Vehicle for Off-Road Driving
{Warning
.Unsecured cargo on the load floor can
be tossed about when driving over
rough terrain. You or your passengers
can be struck by flying objects. Secure
the cargo properly.
.Keep cargo in the cargo area as far
forward and as low as possible. The
heaviest things should be on the floor,
forward of the rear axle.
.Heavy loads on the roof raise the
vehicle's center of gravity, making it
more likely to roll over. You can be
seriously or fatally injured if the
vehicle rolls over. Put heavy loads
inside the cargo area, not on the roof.
For more information about loading the
vehicle, see Vehicle Load Limits 0222 and
Tires 0339.
Environmental Concerns
.Always use established trails, roads, and
areas that have been set aside for public
off-road recreational driving and obey all
posted regulations.
.Do not damage shrubs, flowers, trees,
or grasses or disturb wildlife.
.Do not park over things that burn. See
Parking over Things That Burn 0231.
Driving on Hills
Driving safely on hills requires good
judgment and an understanding of what the
vehicle can and cannot do.
{Warning
Many hills are simply too steep for any
vehicle. Driving up hills can cause the
vehicle to stall. Driving down hills can
cause loss of control. Driving across hills
can cause a rollover. You could be injured
or killed. Do not drive on steep hills.
Before driving on a hill, assess the
steepness, traction, and obstructions. If the
terrain ahead cannot be seen, get out of the
vehicle and walk the hill before driving
further.
When driving on hills:
.Use a low gear and keep a firm grip on
the steering wheel.
.Maintain a slow speed.
.When possible, drive straight up or down
the hill.
.Slow down when approaching the top of
the hill.
.Use headlamps even during the day to
make the vehicle more visible.
{Warning
Driving to the top of a hill at high speed
can cause a crash. There could be a
drop-off, embankment, cliff, or even
another vehicle. You could be seriously
injured or killed. As you near the top of a
hill, slow down and stay alert.
.Never go downhill forward or backward
with either the transmission or transfer
case in N (Neutral). The brakes could
overheat and you could lose control.
{Warning
If the vehicle has the two-speed
automatic or electronic transfer case,
shifting the transfer case to N (Neutral)
can cause your vehicle to roll even if the
transmission is in P (Park). This is because
the N (Neutral) position on the transfer (Continued)