warning GMC YUKON 2021 User Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
28 Keys, Doors, and Windows
The immobilization system is disarmed
when the ignition is turned on or to ACC/
ACCESSORY and a valid remote key is
present in the vehicle.
The security light, in the instrument cluster,
comes on if there is a problem with arming
or disarming the theft-deterrent system.
The system has one or more remote keys
matched to an immobilizer control unit in
the vehicle. Only a correctly matched
remote key will start the vehicle. If the
remote key is ever damaged, you may not
be able to start your vehicle.
When trying to start the vehicle, the
security light may come on briefly.
If the engine does not start and the security
light stays on, there is a problem with the
system. Turn the ignition off and try again.
If the vehicle will not change ignition modes
(ACC/ACCESSORY, on, off), and the remote
key appears to be undamaged, try another
remote key. Or, you may try placing theremote key in the backup location. See
Remote Keyless Entry (RKE) System
Operation
08.
If the ignition modes will not change with
the other remote key or in the backup
location, the vehicle needs service. If the
ignition does change modes, the first
remote key may be faulty. See your dealer.
It is possible for the immobilizer system to
learn new or replacement remote keys. Up
to eight remote keys can be programmed
for the vehicle. To program additional
remote keys, see “Programming Remote
Keys to the Vehicle” underRemote Keyless
Entry (RKE) System Operation 08.
Do not leave the remote key or device that
disarms or deactivates the theft-deterrent
system in the vehicle.
Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things, like
other vehicles, look farther away than
they really are. If you cut too sharply (Continued)
Warning (Continued)
into the right lane, you could hit a
vehicle on the right. Check the inside
mirror or glance over your shoulder
before changing lanes.
The passenger side mirror is convex shaped.
A convex mirror's surface is curved so more
can be seen from the driver seat.
Power Mirrors
To adjust the mirrors: 1. Press
}or|to select the driver or
passenger side mirror. The indicator light
comes on.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
32 Keys, Doors, and Windows
.Tilt
{Warning
The Rear Camera Mirror (RCM) has a
limited view. Portions of the road,
vehicles, and other objects may not be
seen. Do not drive or park the vehicle
using only this camera. Objects may
appear closer than they are. Check the
outside mirrors or glance over your
shoulder when making lane changes or
merging. Failure to use proper care may
result in injury, death, or vehicle damage.
Troubleshooting
See your dealer for service if a blue screen
and
3are displayed in the mirror, and
the display shuts off. Also, push the tab as
indicated to return to the automatic
dimming mode.
The Rear Camera Mirror may not work
properly or display a clear image if:
.There is glare from the sun or headlamps.
This may obstruct objects from view.
If needed, push the tab to turn off the
display.
.Dirt, snow, or other debris blocks the
camera lens. Clean the lens with a soft
damp cloth, or, if equipped, with the Rear
Camera Washer. See Rear Window Wiper/
Washer 098.
.The camera’s mounting on the vehicle has
been damaged, and/or the position or the
mounting angle of the camera has
changed.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Keys, Doors, and Windows 33
Windows{
Warning
Never leave a child, a helpless adult, or a
pet alone in a vehicle, especially with the
windows closed in warm or hot weather.
They can be overcome by the extreme
heat and suffer permanent injuries or
even death from heat stroke.
The vehicle aerodynamics are designed to
improve fuel economy performance. This
may result in a pulsing sound when either
rear window is down and the front windows
are up. To reduce the sound, open either a
front window or the sunroof, if equipped.
Power Windows
{Warning
Children could be seriously injured or
killed if caught in the path of a closing
window. Never leave the remote key in a
vehicle with children. When there are (Continued)
Warning (Continued)
children in the rear seat, use the window
lockout switch to prevent operation of
the windows. SeeKeys07.
The power windows work when the ignition
is on, in ACC/ACCESSORY, or when Retained
Accessory Power (RAP) is active. See
Retained Accessory Power (RAP) 0229.
Using the window switch, press to open or
pull to close the window.
The windows may be temporarily disabled if
they are used repeatedly within a
short time.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
34 Keys, Doors, and Windows
Window Lockout
This feature stops the rear passenger
window switches from working.
With Folding Mirrors
Without Folding Mirrors
.Press2to engage the rear window
lockout feature. The indicator light is on
when engaged.
.Press2again to disengage.
Window Express Movement
All windows can be opened without holding
the window switch. Press the switch down
fully and quickly release to express open the
window.
If equipped, pull the window switch up fully
and quickly release to express close the
window. Briefly press or pull the window switch in
the same direction to stop that window’s
express movement.
Window Automatic Reversal System
The express-close feature will reverse
window movement if it comes in contact
with an object. Extreme cold or ice could
cause the window to auto-reverse. The
window will operate normally after the
object or condition is removed.
Automatic Reversal System Override
{Warning
If automatic reversal system override is
active, the window will not reverse
automatically. You or others could be
injured and the window could be
damaged. Before using automatic reversal
system override, make sure that all
people and obstructions are clear of the
window path.
When the engine is on, override the
automatic reversal system by pulling and
holding the window switch if conditions
prevent it from closing.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 37
Seats and Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . 37
Front Seats
Power Seat Adjustment . . . . . . . . . . . . . . . . 40
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . 40
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 41
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Heated and Ventilated Front Seats . . . . . 44
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . 45
Second Row Seats . . . . . . . . . . . . . . . . . . . . . . 46
Third Row Seats . . . . . . . . . . . . . . . . . . . . . . . . 50
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
How to Wear Seat Belts Properly . . . . . . 54
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 56
Seat Belt Use During Pregnancy . . . . . . . . 59
Seat Belt Extender . . . . . . . . . . . . . . . . . . . . . . 59
Safety System Check . . . . . . . . . . . . . . . . . . . 59
Seat Belt Care . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Replacing Seat Belt System Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Airbag System
Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . 60 Where Are the Airbags? . . . . . . . . . . . . . . . . 62
When Should an Airbag Inflate? . . . . . . . . 63
What Makes an Airbag Inflate? . . . . . . . . 64
How Does an Airbag Restrain? . . . . . . . . . 64
What Will You See after an Airbag
Inflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Passenger Sensing System . . . . . . . . . . . . . 66
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Adding Equipment to the Airbag-Equipped Vehicle . . . . . . . . . . . . . . 69
Airbag System Check . . . . . . . . . . . . . . . . . . . 70
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Child Restraints
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Infants and Young Children . . . . . . . . . . . . . 72
Child Restraint Systems . . . . . . . . . . . . . . . . 74
Where to Put the Restraint . . . . . . . . . . . . . 76
Lower Anchors and Tethers for Children(LATCH System) . . . . . . . . . . . . . . . . . . . . . . . 77
Replacing LATCH System Parts After a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Securing Child Restraints (With the Seat Belt in the Rear Seat) . . . . . . . . . . . . . . . . 84
Securing Child Restraints (With the Seat Belt in the Front Passenger Seat) . . . . . 86
Securing Child Restraints (With the Seat Belt in the Center Front Seat) . . . . . . . . 88
Head Restraints
The vehicle’s front seats have adjustable
head restraints in the outboard seating
positions.
{Warning
With head restraints that are not
installed and adjusted properly, there is a
greater chance that occupants will suffer
a neck/spinal injury in a crash. Do not
drive until the head restraints for all
occupants are installed and adjusted
properly.
If your vehicle has rear head restraints
that fold down, always return them to
the full upright position whenever an
occupant is seated in the seat.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
40 Seats and Restraints
When an occupant or child restraint is in the
seat, always return the head restraint to the
full upright position. Push the head restraint
up and rearward until it locks into place.
Push and pull on the head restraint to make
sure that it is locked.
Front Seats
Power Seat Adjustment
{Warning
You can lose control of the vehicle if you
try to adjust a driver seat while the
vehicle is moving. Adjust the driver seat
only when the vehicle is not moving.
{Warning
The power seats will work with the
ignition off. Children could operate the
power seats and be injured. Never leave
children alone in the vehicle.
To adjust the seat:
.Move the seat forward or rearward by
sliding the control forward or rearward.
.If equipped, raise or lower the front part
of the seat cushion by moving the front
of the control up or down.
.Raise or lower the seat by moving the
rear of the control up or down.
Lumbar Adjustment
.Press and hold the front or rear of the
control to increase or decrease lumbar
support.
.If equipped, press and hold the top or
bottom of the control to raise or lower
lumbar support.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 41
Reclining Seatbacks
To recline the seatback:
.Tilt the top of the control rearward to
recline.
.Tilt the top of the control forward to
raise.
{Warning
Sitting in a reclined position when the
vehicle is in motion can be dangerous.
Even when buckled up, the seat belts
cannot do their job.(Continued)
Warning (Continued)
The shoulder belt will not be against
your body. Instead, it will be in front of
you. In a crash, you could go into it,
receiving neck or other injuries.
The lap belt could go up over your
abdomen. The belt forces would be there,
not at your pelvic bones. This could cause
serious internal injuries.
For proper protection when the vehicle is
in motion, have the seatback upright.
Then sit well back in the seat and wear
the seat belt properly.
Do not have a seatback reclined if the
vehicle is moving.
Memory Seats
If equipped, memory seats allow two drivers
to save and recall their unique seat positions
for driving the vehicle, and a shared exit
position for getting out of the vehicle. Other
feature positions may also be saved, such as
power mirrors and power steering wheel,
if equipped. Memory positions are linked to
remote key 1 or 2 for automatic memory
recalls.
Before saving, adjust all available memory
feature positions. Turn the vehicle on and
then press and release SET; a beep will
sound. Then immediately press and hold 1,

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
44 Seats and Restraints
Obstructions
If something has blocked the driver seat
while recalling a memory position, the recall
may stop. Remove the obstruction and try
the recall again. If the memory position still
does not recall, see your dealer.
Heated and Ventilated Front
Seats
{Warning
If temperature change or pain to the skin
cannot be felt, the seat heater may cause
burns. To reduce the risk of burns, use
care when using the seat heater,
especially for long periods of time. Do
not place anything on the seat that
insulates against heat, such as a blanket,
cushion, cover, or similar item. This may
cause the seat heater to overheat. An
overheated seat heater may cause a burn
or may damage the seat.Heated and Ventilated Seat Buttons Shown,Heated Seat Buttons Similar
If equipped, the buttons are near the
climate controls on the center stack. To
operate, the engine must be on.
Press
Ior+to heat the driver or
passenger seatback.
Press
Jorzto heat the driver or
passenger seatback and cushion.
Press
Cor{, if available, to ventilate the
driver or passenger seat. A ventilated seat
has a fan that pulls or pushes air through
the seat. The air is not cooled. When this feature is off, the heated and
ventilated seat symbols on the buttons are
white. When a heated seat is turned on, the
symbol turns red. When a ventilated seat is
turned on, the symbol turns blue.
Press the button once for the highest
setting. With each press of the button, the
seat will change to the next lower setting,
and then to the off setting. The indicator
lights next to the buttons indicate three for
the highest setting and one for the lowest.
If the heated seats are on high, the level
may automatically be lowered after
approximately 30 minutes.
The passenger seat may take longer to
heat up.
Auto Heated and Ventilated Seats
When the vehicle is on, this feature will
automatically activate the heated or
ventilated seats at the level required by the
vehicle’s interior temperature.
The active high, medium, low, or off heated
or ventilated seat level will be indicated by
the manual heated or ventilated seat
buttons on the center stack. Use the manual
heated or ventilated seat buttons on the
center stack to turn auto heated or
ventilated seats off. If the passenger seat is

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 45
unoccupied, the auto heated or ventilated
seats feature will not activate that seat. The
auto heated or ventilated seats feature can
be programmed to always be enabled when
the vehicle is on.
SeeVehicle Personalization 0126.
Remote Start Heated and Ventilated Seats
During a remote start, the heated or
ventilated seats, if equipped, can be turned
on automatically. When it is cold outside,
the heated seats turn on, and when it is hot
outside the ventilated seats turn on. If the
auto heated or ventilated seats feature,
if equipped, is not turned on, the heated or
ventilated seats may be canceled when the
ignition is turned on. If necessary, press the
heated or ventilated seat button to use the
heated or ventilated seats after the vehicle
is started.
The heated or ventilated seat indicator lights
may turn on during a remote start.
The temperature performance of an
unoccupied seat may be reduced. This is
normal. The remote start heated or ventilated seats
may be enabled or disabled in the vehicle
personalization menu. See
Remote Vehicle
Start 014 and
Vehicle Personalization 0126.
Rear Seats
Rear Seat Reminder
If equipped, the message REAR SEAT
REMINDER LOOK IN REAR SEAT displays
under certain conditions indicating there
may be an item or passenger in the rear
seat. Check before exiting the vehicle.
This feature will activate when a second row
door is opened while the vehicle is on or up
to 10 minutes before the vehicle is turned
on. There will be an alert when the vehicle
is turned off. The alert does not directly
detect objects in the rear seat; instead,
under certain conditions, it detects when a
rear door is opened and closed, indicating
that there may be something in the
rear seat.
The feature is active only once each time
the vehicle is turned on and off, and will
require reactivation by opening and closing
the second row doors. There may be an
alert even when there is nothing in the rear seat; for example, if a child entered the
vehicle through the rear door and left the
vehicle without the vehicle being shut off.
The feature can be turned on or off. See
Vehicle Personalization
0126.
Heated Rear Seats
{Warning
If temperature change or pain to the skin
cannot be felt, the seat heater may cause
burns. See the Warning under Heated
and Ventilated Front Seats 044.
The buttons are on the rear of the center
console.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 47
{Warning
If either seatback is not locked, it could
move forward in a sudden stop or crash.
That could cause injury to the person
sitting there. Always push and pull on
the seatbacks to be sure they are locked.
1. Lift the lever fully while applying pressure to the seatback, and the
seatback will return to the upright
position. If the lever is lifted without
applying pressure, the seat will release
to a folded position.
2. Push and pull on the seatback to make sure it is locked.
Entering and Exiting the Third Row
Manual Fold and Tumble Feature
{Warning
Do not leave the second row seat in a
tumbled position while the vehicle is in
motion. A tumbled seat is not locked.
It can move when the vehicle is in
motion. People in the vehicle could be
injured in a sudden stop or crash. Be sure
to return the seat to the passenger
(Continued)
Warning (Continued)
seating position before driving the
vehicle. Push and pull on the seat to
make sure it is locked into place.
Caution
Folding a rear seat with the seat belts
still fastened may cause damage to the
seat or the seat belts. Always unbuckle
the seat belts and return them to their
normal stowed position before folding a
rear seat.
The second row seats can be folded for
additional cargo space or folded and
tumbled for easy entry and exit to the third
row seat.
Folding and Tumbling the Seat
To fold and tumble the seat: 1. Make sure that there is nothing under, in front of, or on the seat.
2. Lift the lever on the outboard side of theseat to release the seatback.
The seatback will fold forward to create
a flat load floor.