warning light GMC YUKON 2021 Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - CRC - 5/18/21
2 Introduction
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Using this Manual
To quickly locate information about the
vehicle, use the Index in the back of the
manual. It is an alphabetical list of what is
in the manual and the page number where
it can be found.
Danger, Warning, and Caution
Warning messages found on vehicle labels
and in this manual describe hazards and
what to do to avoid or reduce them.
{Danger
Danger indicates a hazard with a high
level of risk which will result in serious
injury or death.
{Warning
Warning indicates a hazard that could
result in injury or death.
Caution
Caution indicates a hazard that could
result in property or vehicle damage.
A circle with a slash through it is a safety
symbol which means“Do not,” “Do not do
this,” or“Do not let this happen.”
Symbols
The vehicle has components and labels that
use symbols instead of text. Symbols are
shown along with the text describing the
operation or information relating to a
specific component, control, message, gauge,
or indicator.
M:Shown when the owner’s manual has
additional instructions or information.
*: Shown when the service manual has
additional instructions or information.
0: Shown when there is more information
on another page — “see page.” Vehicle Symbol Chart
Here are some additional symbols that may
be found on the vehicle and what they
mean. See the features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components Properly
P:Do Not Apply High Pressure Water
B:Engine Coolant Temperature
_:Flame/Fire Prohibited
H: Flammable
[:Forward Collision Alert
R:Fuse Block Cover Lock Location
+:Fuses
j:ISOFIX/LATCH System Child Restraints

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - CRC - 5/18/21
Introduction 5
1.Electric Parking Brake 0240.
2.
gTraction Control/Electronic Stability
Control 0242.
hStop/Start Button (If Equipped). See
Stop/Start System 0229
XPark Assist Button (If Equipped). See
Assistance Systems for Parking or Backing
0 262.
ALane Keep Assist (LKA) 0275 (If
Equipped).
5Hill Descent Control (HDC) 0244 (If
Equipped).
-110V Power Outlet Enable Button
(If Equipped). See Power Outlets0100.
3. Air Vents 0208
4. Turn Signal Lever. See Turn and
Lane-Change Signals 0138.
Windshield Wiper/Washer 097.
Rear Window Wiper/Washer 098.
5. Head-Up Display (HUD) 0122 (If
Equipped). 6. Favorite Switches (Out of View). See
Steering Wheel Controls 0144.
Volume Switches (Out of View). See
Steering Wheel Controls 0144.
7. Instrument Cluster 0104.
8. Hazard Warning Flashers 0137
(Denali Only).
9. Shift Buttons. See Automatic
Transmission 0232.
Electronic Range Select (ERS). See Manual
Mode 0235.
10. Light Sensor. See Automatic Headlamp
System 0136.
11. Infotainment. See Introduction0142.
12. Instrument Panel Storage 089 (If
Equipped).
13. Hazard Warning Flashers 0137.
14. Infotainment Controls. See Overview
0 143.
15. Dual Automatic Climate Control System
0204.
16. Heated and Ventilated Front Seats 044
(If Equipped). 17. Power Outlet (12V Direct Current) (If
Equipped). See Power Outlets0100.
18. Rear Climate Control Buttons. See Rear
Climate Control System 0207.
19. USB Port 0152.
20. Wireless Charging 0101.
21. ENGINE START/STOP. See Ignition
Positions 0226.
22. Steering Wheel Controls 0144.
23. Horn 097.
24. Hood Release. See Hood0310.
25. Steering Wheel Adjustment 096.
26. Cruise Control 0251.
Adaptive Cruise Control (Advanced) 0253
(If Equipped).
Forward Collision Alert (FCA) System
0 267 (If Equipped).
Heated Steering Wheel 096 (If
Equipped).
27. Trailer Brake Control Panel (If Equipped). SeeTowing Equipment 0287.
28. Data Link Connector (DLC) (Out of View). SeeMalfunction Indicator Lamp (Check
Engine Light) 0111.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Keys, Doors, and Windows 25
Power Assist Steps
{Warning
To avoid personal injury or property
damage, before entering or exiting the
vehicle, be sure the power assist step is
fully extended. Do not step on the power
assist step while it is moving. Never place
hands or other body parts between the
extended power assist step and the
vehicle.
If equipped, the power assist steps will
deploy when the door is opened and
automatically retract three seconds after the
door is closed. The power assist steps will
retract immediately if the vehicle starts
moving.
Disable the power assist steps before jacking
or placing any object under the vehicle. Too
much ice buildup may prevent deployment
of the power assist steps. Check the step
position before exiting the vehicle. If this
happens, disable the power assist steps,
clear the ice, then enable the assist steps
and confirm normal function prior to use. Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse
direction if they encounter an obstruction
when opening or closing. Remove the
obstruction, then open and close the door
on the same side to complete the motion of
the assist steps. If the obstruction is not
cleared, the assist steps remain extended
while driving.
To extend or retract both power assist steps
for cleaning, see
Vehicle Personalization
0 126.
Enable/Disable
To enable or disable the power assist steps,
see Vehicle Personalization 0126.
Vehicle Security
This vehicle has theft-deterrent features;
however, they do not make the vehicle
impossible to steal.
Vehicle Alarm System
The indicator light, on the driver door near
the window, indicates the status of the
system. See Power Door Locks 016
Arming the Alarm System
1. Turn off the vehicle.
2. Lock the vehicle in one of three ways:
.Use the remote key.
.Use the Keyless Access system.
.With a door open, pressQon the
interior of the door.
3. After 30 seconds the alarm system will arm, and the indicator light will begin to
slowly flash. Pressing
Qon the remote

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
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
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 53
{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.
3. Push and pull on the seatback to make sure it is locked in place.
{Warning
A seat belt that is improperly routed, not
properly attached, or twisted will not
provide the protection needed in a crash.
The person wearing the belt could be
seriously injured. After raising the rear
seatback, always check to be sure that
the seat belts are properly routed and
attached, and are not twisted.
4. Reconnect the center seat belt mini-latch to the mini-buckle. Do not let it twist.
5. Pull on the seat belt to be sure the mini-latch is secure. Folding the Third Row Seats from the
Overhead Console
To fold the seats from the overhead console,
if equipped:
The vehicle must be in P (Park) for this
feature to work.
1. Press and hold the switch to fold the third row seatback.
The left switch folds the left seatback,
and the right switch folds the right
seatback.
2. Repeat the steps for the other seatback, if desired.
3. Press and hold the switch to return the seatback to the seating position. If the red light on the switch is
illuminated, the third row seatback is not
in the seating position.
There are additional switches which can be
used to fold the third row seatbacks from
the cargo area. See Third Row Seats050.
Seat Belts
This section describes how to use seat belts
properly, and some things not to do.
{Warning
Do not let anyone ride where a seat belt
cannot be worn properly. In a crash,
if you or your passenger(s) are not
wearing seat belts, injuries can be much
worse than if you are wearing seat belts.
You can be seriously injured or killed by
hitting things inside the vehicle harder or
by being ejected from the vehicle. In
addition, anyone who is not buckled up
can strike other passengers in the vehicle.
It is extremely dangerous to ride in a
cargo area, inside or outside of a vehicle.
In a collision, passengers riding in these
areas are more likely to be seriously
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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60 Seats and Restraints
{Warning
Do not bleach or dye seat belt webbing.
It may severely weaken the webbing. In
a crash, they might not be able to
provide adequate protection. Clean and
rinse seat belt webbing only with mild
soap and lukewarm water. Allow the
webbing to dry.
Replacing Seat Belt System Parts
after a Crash
{Warning
A crash can damage the seat belt system
in the vehicle. A damaged seat belt
system may not properly protect the
person using it, resulting in serious injury
or even death in a crash. To help make
sure the seat belt systems are working
properly after a crash, have them
inspected and any necessary
replacements made as soon as possible.
After a minor crash, replacement of seat
belts may not be necessary. But the seat
belt assemblies that were used during any crash may have been stressed or damaged.
See your dealer to have the seat belt
assemblies inspected or replaced.
New parts and repairs may be necessary
even if the seat belt system was not being
used at the time of the crash.
Have the seat belt pretensioners checked if
the vehicle has been in a crash, or if the
airbag readiness light stays on after you
start the vehicle or while you are driving.
See
Airbag Readiness Light 0109.
Airbag System
The vehicle has the following airbags:
.A frontal airbag for the driver
.A frontal airbag for the front outboard
passenger
.A seat-mounted side impact airbag for the
driver
.A seat-mounted side impact airbag for the
front outboard passenger
.A roof-rail airbag for the driver and for
the second and third row passengers
seated directly behind the driver
.A roof-rail airbag for the front outboard
passenger and the second and third row
passengers seated directly behind the
front outboard passenger
The vehicle may have the following airbag:
.A front center airbag for the driver and
front outboard passenger
All vehicle airbags have the word AIRBAG on
the trim or on a label near the deployment
opening.
For frontal airbags, the word AIRBAG is on
the center of the steering wheel for the
driver and on the instrument panel for the
front outboard passenger.
For the front center airbag, the word AIRBAG
is on the inboard side of the driver seatback.
For seat-mounted side impact airbags, the
word AIRBAG is on the side of the seatback
or side of the seat closest to the door.
For roof-rail airbags, the word AIRBAG is on
the ceiling or trim.
Airbags are designed to supplement the
protection provided by seat belts. Even
though today's airbags are also designed to
help reduce the risk of injury from the force
of an inflating bag, all airbags must inflate
very quickly to do their job.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 61
Here are the most important things to know
about the airbag system:
{Warning
You can be severely injured or killed in a
crash if you are not wearing your seat
belt, even with airbags. Airbags are
designed to work with seat belts, not
replace them. Also, airbags are not
designed to inflate in every crash. In
some crashes seat belts are the only
restraint. SeeWhen Should an Airbag
Inflate? 063.
Wearing your seat belt during a crash
helps reduce your chance of hitting
things inside the vehicle or being ejected
from it. Airbags are “supplemental
restraints” to the seat belts. Everyone in
the vehicle should wear a seat belt
properly, whether or not there is an
airbag for that person.
{Warning
Because airbags inflate with great force
and faster than the blink of an eye,
anyone who is up against, or very close
(Continued)
Warning (Continued)
to any airbag when it inflates can be
seriously injured or killed. Do not sit
unnecessarily close to any airbag, as you
would be if sitting on the edge of the
seat or leaning forward. Seat belts help
keep you in position before and during a
crash. Always wear a seat belt, even with
airbags. The driver should sit as far back
as possible while still maintaining control
of the vehicle. The seat belts and the
front outboard passenger airbags are
most effective when you are sitting well
back and upright in the seat with both
feet on the floor.
Occupants should not lean on or sleep
against the front center armrest or
console in vehicles with a front center
airbag.
Occupants should not lean on or sleep
against the door or side windows in
seating positions with seat-mounted side
impact airbags and/or roof-rail airbags.
{Warning
Children who are up against, or very
close to, any airbag when it inflates can
be seriously injured or killed. Always
secure children properly in the vehicle. To
read how, seeOlder Children 071 or
Infants and Young Children 072.
There is an airbag readiness light on the
instrument cluster, which shows the airbag
symbol.
The system checks the airbag electrical
system for malfunctions. The light tells you
if there is an electrical problem. See Airbag
Readiness Light 0109.