
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 71
Child Restraints
Older Children
Older children who have outgrown booster
seats should wear the vehicle’s seat belts.
The manufacturer instructions that come
with the booster seat state the weight and
height limitations for that booster. Use a
booster seat with a lap-shoulder belt until
the child passes the fit test below:
.Sit all the way back on the seat. Do the
knees bend at the seat edge? If yes,
continue. If no, return to the booster seat.
.Buckle the lap-shoulder belt. Does the
shoulder belt rest on the shoulder? If yes,
continue. If no, try using the rear seatbelt comfort guide, if available. See
“Rear
Seat Belt Comfort Guides” under
Lap-Shoulder Belt 056. If a comfort guide
is not available, or if the shoulder belt
still does not rest on the shoulder, then
return to the booster seat.
.Does the lap belt fit low and snug on the
hips, touching the thighs? If yes, continue.
If no, return to the booster seat.
.Can proper seat belt fit be maintained for
the length of the trip? If yes, continue.
If no, return to the booster seat.
Q: What is the proper way to wear seat belts?
A: An older child should wear a lap-shoulder
belt and get the additional restraint a
shoulder belt can provide. The shoulder
belt should not cross the face or neck.
The lap belt should fit snugly below the
hips, just touching the top of the thighs.
This applies belt force to the child's
pelvic bones in a crash. It should never
be worn over the abdomen, which could
cause severe or even fatal internal
injuries in a crash.
Also see “Rear Seat Belt Comfort Guides”
under Lap-Shoulder Belt 056. According to accident statistics, children are
safer when properly restrained in a rear
seating position.
In a crash, children who are not buckled up
can strike other people who are buckled up,
or can be thrown out of the vehicle. Older
children need to use seat belts properly.{Warning
Never allow more than one child to wear
the same seat belt. The seat belt cannot
properly spread the impact forces. In a
crash, they can be crushed together and
seriously injured. A seat belt must be
used by only one person at a time.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
74 Seats and Restraints
designed to be used in a motor vehicle. If it
is, the child restraint will have a label saying
that it meets federal motor vehicle safety
standards.
The instruction manual that is provided with
the child restraint states the weight and
height limitations for that particular child
restraint. In addition, there are many kinds
of child restraints available for children with
special needs.
{Warning
To reduce the risk of neck and head
injury in a crash, infants and toddlers
should be secured in a rear-facing child
restraint until age two, or until they
reach the maximum height and weight
limits of their child restraint.
{Warning
A young child's hip bones are still so
small that the vehicle seat belt may not
remain low on the hip bones, as it
should. Instead, it may settle up around
the child's abdomen. In a crash, the belt
would apply force on a body area that is(Continued)
Warning (Continued)
unprotected by any bony structure. This
alone could cause serious or fatal injuries.
To reduce the risk of serious or fatal
injuries during a crash, young children
should always be secured in an
appropriate child restraint.
Child Restraint Systems
Rear-Facing Infant Restraint
A rear-facing child restraint provides
restraint with the seating surface against
the back of the infant. The harness system holds the infant in place
and, in a crash, acts to keep the infant
positioned in the restraint.
Forward-Facing Child Restraint
A forward-facing child restraint provides
restraint for the child's body with the
harness.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Instruments and Controls 117
This light comes on when Snow Mode is
selected.
This light comes on when Terrain Mode is
selected.
This light comes on when Off-Road Mode is
selected.
This light comes on when the Tow/Haul
Mode is selected.
Four Corner Air Suspension Light
This light comes on when the air suspension
is raised to maximum ground clearance
height.
This light comes on when the air suspension
is raised to increased ground clearance
height.
It will flash green and give an alert to
indicate that the vehicle is changing to a
higher ride height.
This light comes on when the air suspension
is lowered for easy entry and exit from the
vehicle.
It will flash green and give an alert to
indicate that the vehicle is changing to a
lower ride height.
This light comes on when the air suspension
is in Service Mode or Alignment Mode.
SeeFour Corner Air Suspension System
0 248.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Instruments and Controls 125
Care of the HUD
Clean the inside of the windshield to remove
any dirt or film that could reduce the
sharpness or clarity of the HUD image.
Clean the HUD lens with a soft cloth
sprayed with glass cleaner. Wipe the lens
gently, then dry it.
HUD Troubleshooting
Check that:
.Nothing is covering the HUD lens.
.The HUD brightness setting is not too
dim or too bright.
.The HUD is adjusted to the proper height.
.Polarized sunglasses are not worn.
.The windshield and HUD lens are clean.
If the HUD image is not correct, contact
your dealer.
The windshield is part of the HUD system.
See Windshield Replacement 0330.
Vehicle Messages
Messages displayed on the DIC indicate the
status of the vehicle or some action that
may be needed to correct a condition.
Multiple messages may appear one after
another.
The messages that do not require
immediate action can be acknowledged and
cleared by pressing
V. The messages that
require immediate action cannot be cleared
until that action is performed.
All messages should be taken seriously;
clearing the message does not correct the
problem.
If a SERVICE message appears, see your
dealer.
Follow the instructions given in the
messages. The system displays messages
regarding the following topics:
.Service Messages
.Fluid Levels
.Vehicle Security
.Brakes
.Steering
.Ride Control Systems
.Driver Assistance Systems
.Cruise Control
.Lighting and Bulb Replacement
.Wiper/Washer Systems
.Doors and Windows
.Seat Belts
.Airbag Systems
.Engine and Transmission
.Tire Pressure
.Battery
.Four Corner Air Suspension System
Engine Power Messages
REDUCED ACCELERATION DRIVE
WITH CARE
This message displays when the vehicle's
propulsion power is reduced. A reduction in
propulsion power can affect the vehicle's
ability to accelerate. If this message is on,
but there is no observed reduction in
performance, proceed to your destination.
Under certain conditions the performance
may be reduced the next time the vehicle is
driven. The vehicle may be driven while this
message is on, but maximum acceleration
and speed may be reduced. Anytime this
message stays on, or displays repeatedly,
the vehicle should be taken to your dealer
for service as soon as possible.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
130 Instruments and Controls
Passive Door Lock
This allows passive locking to be turned on
or off and selects feedback. SeeRemote
Keyless Entry (RKE) System Operation 08.
Touch Off, On with Horn Chirp, or On.
Remote Left in Vehicle Alert
This feature sounds an alert when the
Remote Key is left in the vehicle.
Touch Off or On.
Remote Removed from Vehicle Alert
This feature beeps the horn 3 times when
exiting a running vehicle with the
Remote Key.
Touch Off or On.
Ride Height
Touch and the following may display:
.Automatic Entry/Egress
Automatic Entry/Egress
This feature specifies if the vehicle will
automatically lower to make it easier to
enter or exit the vehicle.
Touch Off or On.
Running Boards
Touch and the following may display:
.Automatic Running Boards
.Deploy Running Boards
Automatic Running Boards
This feature specifies the position and use of
the running boards. See Power Assist Steps
0 25.
Touch Off or On.
Deploy Running Boards
This feature moves the running boards to a
deployed position so they can be used with
the doors closed.
Touch Off or Deploy.
Seating Position
Touch and the following may display:
.Seat Entry Memory
.Seat Exit Memory
Seat Entry Memory
This feature automatically recalls the
previously stored 1 or 2 button positions
when the ignition is changed from off to on
or ACC/ACCESSORY. See Memory Seats041.
Touch Off or On. Seat Exit Memory
This feature automatically recalls the
previously stored exit button position when
the ignition is changed from on or ACC/
ACCESSORY to off and the driver door is
open. See
Memory Seats 041.
Touch Off or On.
Suspension
Touch and the following may display:
.Service Mode
.Alignment Mode
Service Mode
This feature disables the air suspension
system and is used to prevent unintended
raising or lowering of the suspension..
Touch Off or On.
Alignment Mode
This feature will optimize the vehicle height
to provide the most accurate wheel
alignment.
Touch Off or On.
Teen Driver
See “Teen Driver” underSettings 0187.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
246 Driving and Operating
6Snow/Ice Mode :Snow/Ice improves
vehicle acceleration on snow and ice covered
roads. When active, Snow/Ice Mode will
adjust acceleration to optimize traction on
slippery surfaces. This can compromise the
acceleration on dry asphalt. This feature is
not intended for use when the vehicle is
stuck in sand, mud, ice, snow, or gravel.
If the vehicle becomes stuck see If the
Vehicle Is Stuck 0221.
7Off-Road Mode : Use this mode for
off-road recreational driving. Off-Road Mode
should be used to improve driving at
moderate speeds, on grass, gravel, dirt,
unpaved roads, or snow-covered roads. The
accelerator pedal is tuned for off-road use.
This mode modifies pedal mapping, AWD,
steering, ride height, ABS, ESC, and TCS
performance. For more information on
off-road driving, see Off-Road Driving0216.
_Tow/Haul Mode : For more
information on Tow/Haul Mode, see Tow/
Haul Mode 0235.
If equipped, select Terrain Mode by pressing
the
gbelow the 4mtransfer case
button.
gTerrain Mode : Use this mode when
traveling on very rough roads at very low
speeds, such as a two-track or heavily rutted
road. This can also be used for pulling a
boat out of the water on a trailer. When in
Terrain Mode, the vehicle will shift
automatically but will hold a lower gear
longer to maximize engine torque. This
mode has a unique pedal map and
transmission shift pattern for better control
at lower speeds and over rough terrain. This
mode modifies accelerator pedal mapping, transmission shift pattern, ride height,
suspension, steering, AWD, eSLD, ESC
performance and TCS performance.
When the vehicle comes to a stop on an
upward grade, Automatic Vehicle Hold is
engaged until the driver presses the
accelerator pedal. Stop/Start and cruise
control are disabled in Terrain Mode.
Active Braking during lift throttle will be
engaged. This feature automatically applies
light braking to simulate heavy engine
braking of four-wheel-dive low. It also
applies light braking in D (Drive) until the
vehicle is at idle speeds. In M1 and M2 light
braking will typically bring the vehicle to a
stop. Active Braking during lift throttle will
also reduce trailer braking.
Terrain Mode will automatically exit to
Normal Mode if the brake temperatures
become too hot, electronic parking brake
becomes inoperable or the vehicle cannot
perform braking or vehicle hold.
For more information on off-road driving,
see
Off-Road Driving 0216 and
Hill and Mountain Roads 0220.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
248 Driving and Operating
Locking Rear Axle
Vehicles with a locking rear axle can give
more traction on snow, mud, ice, sand,
or gravel. It works like a standard axle most
of the time, but when traction is low, this
feature will allow the rear wheel with the
most traction to move the vehicle.
Four Corner Air Suspension
System
The Four Corner Air Suspension feature
provides full time load leveling capability
along with the benefit of adjusting ride
height for increased convenience and
capability.
{Warning
To help avoid personal injury or death,
make sure the area underneath the
vehicle and inside the wheel wells is clear
when lowering the vehicle.
{Warning
To help avoid personal injury or death,
always select the lowest ride height for
the current driving conditions. Higher ride
heights raise the vehicle's center of
gravity, increasing the chance of a
rollover during extreme maneuvers.
{Warning
Heavy loads on the roof rack will make
the vehicle's center of gravity higher,
increasing the possibility of a rollover. To
avoid losing control of the vehicle, always
select the normal height setting and
avoid high speeds, sudden starts, sharp
turns, sudden braking, or abrupt
maneuvers when carrying cargo on the
roof rack.Changing Ride Height
Press the Ride Height button to open the
Ride Height Menu on the Instrument Panel.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 249
Turn the knob left or right to select the
desired ride height in the menu. To finalize
the selection, either press the Ride Height
button again or wait three seconds for the
menu to timeout. Ride Heights that are
unavailable for selection will be greyed out
in the menu.
Ride Height Descriptions
Normal Height is the standard vehicle height
used for everyday driving.
Entry/Exit Height is 50 mm (2 in) lower than
Normal Height. This ride height lowers the
vehicle for easy entry and exit from the
vehicle as well as providing a lower height
for loading and unloading cargo.
This ride height can be selected in the Ride
Height Menu at any vehicle speed. When
Entry/Exit Height is selected at higher
speeds, the vehicle will wait to lower until
the vehicle slows to less than
12 km/h (7 mph).
The vehicle will automatically raise to
Normal Height from Entry/Exit Height when
speed increases above 8 km/h (5 mph). If no
door has been opened since lowering to
Entry/Exit Height, the vehicle will wait to
raise to Normal Height until 30 km/h(19 mph). This gives the driver more
flexibility when lowering to Entry/Exit
Height for passenger pick up and drop off.
The driver can enable Automatic Entry/
Egress Mode to automatically lower to
Entry/Exit Height when the vehicle is shifted
to P (PARK). Automatic Entry/Egress Mode
may be enabled via the infotainment screen
under Settings/Vehicle/Ride Height. When
the vehicle is higher than Normal Height,
Automatic Entry/Egress Mode is disabled.
When the vehicle is in Tow/Haul Driver
Mode, Off-Road Driver Mode, or it senses a
trailer is connected, Automatic Entry/Egress
Mode is disabled.
Increased Height is 25 mm (1 in) higher than
Normal Height. This ride height raises the
vehicle for off-road use, allows for higher
speeds than Maximum Height, and is only
available with specific optional content.
Increased Height can be selected in the Ride
Height Menu while vehicle speed is less
than 80 km/h (50 mph). If vehicle speed
exceeds 80 km/h (50 mph), the vehicle will
automatically lower to Normal Height.
Off-Road Driver Mode and Terrain Driver
Mode will automatically set Increased
Height when vehicle speed is less than
80 km/h (50 mph). If vehicle speed exceeds80 km/h (50 mph), the vehicle will lower to
Normal Height. Normal Height will be
maintained until vehicle speed is slowed to
less than 16 km/h (10 mph) and then the
vehicle will automatically raise back to
Increased Height.
The vehicle will automatically lower from
Increased Height to Normal Height to
provide improved stability if aggressive
maneuvers are detected.
Maximum Height is 50 mm (2 in) higher
than Normal Height. This ride height raises
the vehicle for off-road use and is only
available with specific optional content.
To raise the vehicle to Maximum Height,
first shift the transfer case to 4
n. Once the
transfer case is in 4
nand vehicle speed is
less than 48 km/hr (30 mph), select
Maximum Height in the Ride Height Menu.
If vehicle speed exceeds 48 km/h, the
vehicle will automatically lower to Increased
Height.
The vehicle will automatically lower from
Maximum Height to Normal Height to
provide improved stability if aggressive
maneuvers are detected.