warning 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
Vehicle Care 363
12. Tighten the nuts firmly in a crisscrosssequence as shown by turning the wheel
wrench clockwise.
{Warning
Wheel nuts that are improperly or
incorrectly tightened can cause the
wheels to become loose or come off. The
wheel nuts should be tightened with a
torque wrench to the proper torque
specification after replacing. Follow the
torque specification supplied by the
aftermarket manufacturer when using
(Continued)
Warning (Continued)
accessory locking wheel nuts. See
Capacities and Specifications0396 for
original equipment wheel nut torque
specifications.
Caution
Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To
avoid expensive brake repairs, evenly
tighten the wheel nuts in the proper
sequence and to the proper torque
specification. See Capacities and
Specifications 0396 for the wheel nut
torque specification.
When reinstalling the regular wheel and tire,
also reinstall either the center cap or the
bolt-on hub cap, depending on which one
the vehicle has.
.For center caps, line up the tab on the
center cap with the slot in the wheel. The
cap only goes in one way. Place the cap
on the wheel and press until it snaps into
place.
.For bolt-on hub caps, line up the plastic
nut caps with the wheel nuts and tighten
clockwise by hand to get them started.
Then tighten with the wheel wrench
until snug.
Storing a Flat or Spare Tire and Tools
{Warning
Storing a jack, a tire, or other equipment
in the passenger compartment of the
vehicle could cause injury. In a sudden
stop or collision, loose equipment could
strike someone. Store all these in the
proper place.
{Warning
Failure to follow these tire storage
instructions carefully could result in
personal injury or property damage if the
hoist cable fails or if the tire comes loose.
Make sure the tire is stored securely
before driving.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
364 Vehicle Care
Caution
Always store the spare tire or flat tire
with the valve stem pointed up. Stowing
a tire with the valve stem pointed down
could result in damage to the wheel.
Caution
The tire hoist is designed to be raised
and lowered with tension on the cable.
If the hoist must be raised or lowered
without a tire attached, do so only by
hand, and at a slow pace, to avoid
damaging the mechanism. Do not use
power tools.
{Warning
An improperly stored spare tire could
come loose and cause a crash. To avoid
personal injury or property damage,
always store the spare tire when the
vehicle is parked on a level surface.If the vehicle has 275/60R20 or 275/50R22
size tires, the flat tire must be stored inside
of the vehicle using the flat tire secure strap
inside the glove box. See
“Storing a Flat Tire
Inside of the Vehicle” later in this section.
If the vehicle has 265/65R18 or 275/55R20
size tires, store the flat tire under the rear
of the vehicle in the spare tire carrier. Refer
to the following graphics and instructions:
1. Hoist Assembly
2. Hoist Shaft
3. Hoist Shaft Access Cover/Hole
4. Jack Handle Extension
5. Wheel Wrench
6. Spare Tire Lock
7. Hoist End of Extension Tool 8. Hoist Shaft Access Hole
9. Spare Tire (Valve Stem Pointed Up)
10. Tire/Wheel Retainer
11. Hoist Cable
1. Put the tire (9) on the ground at the rear
of the vehicle with the valve stem
pointed up, and to the rear.
2. Tilt the tire toward the vehicle. Separate the tire/wheel retainer from the guide
pin. Pull the pin through the center of
the wheel. Tilt the retainer down
through the center wheel opening.
Make sure the retainer is fully seated
across the underside of the wheel.
3. Assemble the jack handle extensions (4)and wheel wrench (5).

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 367
If equipped with a temporary use full-size
spare tire, it is indicated on the tire sidewall.
SeeTire Sidewall Labeling 0341. This spare
tire should not be driven on over 112 km/h
(70 mph), or 88 km/h (55 mph) when
pulling a trailer, at the proper inflation
pressure. Repair and replace the road tire as
soon as it is convenient, and stow the spare
tire for future use.
Caution
If the vehicle has four-wheel drive and a
different size spare tire is installed, do
not drive in four-wheel drive until the flat
tire is repaired and/or replaced. The
vehicle could be damaged and the repairs
would not be covered by the warranty.
Never use four-wheel drive when a
different size spare tire is installed on the
vehicle.
The vehicle may have a different size spare
tire than the road tires originally installed
on the vehicle. This spare tire was developed
for use on this vehicle, so it is all right to
drive on it. If the vehicle has four-wheel
drive and a different size spare tire is
installed, drive only in two-wheel drive. After installing the spare tire on the vehicle,
stop as soon as possible and check that the
spare is correctly inflated. The spare tire is
made to perform well at speeds up to
112 km/h (70 MPH) at the recommended
inflation pressure, so you can finish
your trip.
Have the damaged or flat road tire repaired
or replaced and installed back onto the
vehicle as soon as possible so the spare tire
will be available in case it is needed again.
Do not mix tires and wheels of difference
sizes, because they will not fit. Keep the
spare tire and its wheel together.
If the vehicle has a spare tire that does not
match the original road tires and wheels in
size and type, do not include the spare in
the tire rotation.
Jump Starting
Jump Starting - North America
For more information about the vehicle
battery, see
Battery - North America 0327. If the vehicle's battery (or batteries) has run
down, you may want to use another vehicle
and some jumper cables to start your
vehicle. Be sure to use the following steps
to do it safely.
{Warning
WARNING:
Battery posts, terminals, and
related accessories contain lead and lead
compounds, chemicals known to the
State of California to cause cancer and
birth defects or other reproductive harm.
Batteries also contain other chemicals
known to the State of California to cause
cancer. WASH HANDS AFTER HANDLING.
For more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition 65 Warning 0309
and the back cover.
{Warning
Batteries can hurt you. They can be
dangerous because:
.They contain acid that can burn you.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
368 Vehicle Care
Warning (Continued)
.They contain gas that can explode or
ignite.
.They contain enough electricity to
burn you.
If you do not follow these steps exactly,
some or all of these things can hurt you.
Caution
Ignoring these steps could result in costly
damage to the vehicle that would not be
covered by the vehicle warranty. Trying
to start the vehicle by pushing or pulling
it will not work, and it could damage the
vehicle.5.3L V8 Shown, 6.2L V8 Similar
1. Good Battery Positive Terminal
2. Good Battery Negative Terminal
3. Discharged Battery Remote Negative Terminal
4. Discharged Battery Remote Positive Terminal
The jump start positive post (1) and negative
post (2) are on the battery of the vehicle
providing the jump start.
The jump start positive post (4) and the
negative grounding point (3) for the
discharged battery are on the passenger side
of the vehicle. The positive jump start connection for the
discharged battery is under a cover. Slide
the cover to expose the terminal.
1. Check the other vehicle. It must have a 12-volt battery with a negative ground
system.
Caution
If the other vehicle does not have a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
a vehicle that has a 12-volt system with a
negative ground for jump starting.
2. If you have a vehicle with a diesel engine with two batteries, you should
know before you begin that, especially in
cold weather, you may not be able to
get enough power from a single battery
in another vehicle to start your diesel
engine. If your vehicle has more than
one battery, using the battery that is
closer to the starter will reduce electrical
resistance. This is located on the
passenger side, in the rear of the engine
compartment.
3. Get the vehicles close enough so the jumper cables can reach, but be sure the
vehicles are not touching each other.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 369
If they are, it could cause an unwanted
ground connection. You would not be
able to start your vehicle, and the bad
grounding could damage the electrical
systems.
To avoid the possibility of the vehicles
rolling, set the parking brake firmly on
both vehicles involved in the jump start
procedure. Put an automatic transmission
in P (Park) or a manual transmission in
Neutral before setting the parking brake.
If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear,
not in N (Neutral).
Caution
If any accessories are left on or plugged
in during the jump starting procedure,
they could be damaged. The repairs
would not be covered by the vehicle
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off on both vehicles. Unplug unnecessary accessories plugged
into the accessory power outlets. Turn
off the radio and all the lamps that are not needed. This will avoid sparks and
help save both batteries. And it could
save the radio!
5. Open the hood on the other vehicle and locate the positive (+) and negative (−)
terminal locations on that vehicle.
The positive (+) terminal is under a red
plastic cover at the positive battery post.
To uncover the positive (+) terminal,
open the red plastic cover.
For more information on the location of
the remote positive (+) and remote
negative (−) terminals, see Engine
Compartment Overview 0312.{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
6. Check that the jumper cables do not have loose or missing insulation. If they
do, you could get a shock. The vehicles
could be damaged too.
Before you connect the cables, here are
some basic things you should know.
Positive (+) will go to positive (+) or to a
remote positive (+) terminal if the

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
372 Vehicle Care
Dinghy Towing
Two-Wheel-Drive Vehicles
Caution
If the two-wheel-drive vehicle is towed
with all four wheels on the ground, the
drivetrain components could be damaged.
The repairs would not be covered by the
vehicle warranty.
Two-wheel-drive vehicles should not be
towed with all four wheels on the ground. Four-Wheel-Drive Vehicles
Only dinghy tow four-wheel-drive vehicles
with a two speed transfer case that has an
N (Neutral) and a 4
nsetting.
{Warning
Shifting a four-wheel-drive vehicle's
transfer case into N (Neutral) can cause
the vehicle to roll even if the
transmission is in P (Park). You or others
could be injured. Set the parking brake
before shifting the transfer case to
N (Neutral).
To dinghy tow: 1. Position the vehicle being towed behind
the tow vehicle, facing forward and on a
level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into N (Neutral)” under
Four-Wheel Drive 0236 for the proper
procedure. Check that the vehicle is in
N (Neutral) by shifting the transmission
to R (Reverse) and then to D (Drive).
There should be no movement of the
vehicle while shifting.
5. Shift the transmission to P (Park).
Caution
Failure to tow the vehicle with the
transmission in P (Park) can cause
damage to the transmission.
6. Turn off the engine.
7. Place the vehicle in ACC/ACCESSORY mode by pressing the start button
without stepping on the brake pedal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 373
8. Release the parking brake only when youare confident it is secured to tow vehicle
and will not roll.
Before going on to the next step, be
sure to take the mechanical key with
you. It will be needed to re-enter the
vehicle after the power is disconnected.
See “Drive Door Key Lock Cylinder
Access” underDoor Locks 015.
9. Disconnect the negative battery cable at the battery and secure the nut and bolt.
Cover the negative battery post with a
non-conductive material to prevent any
contact with the negative battery
terminal.
Caution
Failure to disconnect the negative battery
cable or to have it contact the terminals
can cause damage to the vehicle.
10. Move the steering wheel to make sure the steering column is unlocked.
Caution
If the steering column is locked, vehicle
damage may occur. 11. Rock the vehicle to make sure the
parking brake is not set and transfer case
is in N (Neutral).
Caution
Towing the vehicle with the parking
brake set can damage it. Always release
the parking brake prior to towing the
vehicle.
Disconnecting the Towed Vehicle
Before disconnecting the towed vehicle: 1. Park on a level surface.
2. Connect the battery.
3. Apply the brake pedal.
{Warning
The vehicle can roll when the brake pedal
is released. Always apply and hold the
brake pedal when setting the parking
brake. Make sure the parking brake is
fully engaged before releasing the brake
pedal.
4. Start the engine and shift the transfer case out of N (Neutral) to 2
m. See “Shifting out of N (Neutral)”
under
Four-Wheel Drive 0236. See your dealer
if the transfer case cannot be shifted out
of N (Neutral).
5. Check that the vehicle is in 2
mby
shifting the transmission to R (Reverse)
and then to D (Drive). There should be
movement of the vehicle while shifting.
6. Shift the transmission to P (Park) and turn off the vehicle.
7. Set the parking brake.
8. Release the parking brake.
9. Disconnect the vehicle from the tow vehicle.
10. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 381
Cargo Cover and Convenience Net
If equipped, wash with warm water and
mild detergent. Do not use chlorine bleach.
Rinse with cold water, and then dry
completely.
Care of Seat Belts
Keep belts clean and dry.
{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.
Floor Mats
{Warning
If a floor mat is the wrong size or is not
properly installed, it can interfere with
the pedals. Interference with the pedals
can cause unintended acceleration and/or
increased stopping distance which can(Continued)
Warning (Continued)
cause a crash and injury. Make sure the
floor mat does not interfere with the
pedals.
Use the following guidelines for proper floor
mat usage:
.The original equipment floor mats were
designed for your vehicle. If the floor
mats need replacing, it is recommended
that GM certified floor mats be
purchased. Non-GM floor mats may not
fit properly and may interfere with the
pedals. Always check that the floor mats
do not interfere with the pedals.
.Do not use a floor mat if the vehicle is
not equipped with a floor mat retainer on
the driver side floor.
.Use the floor mat with the correct side
up. Do not turn it over.
.Do not place anything on top of the
driver side floor mat.
.Use only a single floor mat on the
driver side.
.Do not place one floor mat on top of
another.
Removing and Replacing the Floor Mats
Pull up on the rear of the driver side floor
mat to unlock each retainer and remove.
Reinstall by lining up the floor mat retainer
openings over the carpet retainers and
snapping into position.
Make sure the floor mat is properly secured
in place.
Verify the floor mat does not interfere with
the pedals.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
382 Vehicle Care
Cleaning Rubber Floor Mats (All-Weather
Mats and Floor Liners)
{Warning
Do not use cleaners that contain silicone,
wax-based products, or cleaners that
increase gloss on rubber floor mats/liners.
These cleaners can permanently change
the appearance and feel of the rubber
and can make the floor mats/liners
slippery. Your foot could slip while
operating the vehicle, and you could lose
control, resulting in a crash. You or
others could be injured.
Use a soft cloth and/or a brush dampened
with water to remove dust and loose dirt.
For more thorough cleaning, use a mild soap
solution.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
384 Service and Maintenance
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. SeeVehicle
Load Limits 0222.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel (5.3L Engine) 0277 or
Recommended Fuel (6.2L Engine) 0277.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal chart. The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather
.Mainly driven in hilly or mountainous
terrain
.Frequently towing a trailer
.Used for high speed or competitive
driving
.Used for taxi, police, or delivery service
Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe chart.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See Doing Your
Own Service Work 0310.
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. See Engine Oil
0 315.
Once a Month
.Check the tire inflation pressures,
including the spare. See Tire Pressure
0 344.
.Inspect the tires for wear. See Tire
Inspection 0349.
.Check the windshield washer fluid level.
See Washer Fluid 0324.
Engine Oil Change
When the CHANGE ENGINE OIL SOON
message displays, have the engine oil and
filter changed within the next 1 000 km/
600 mi. If driven under the best conditions,
the engine oil life system may not indicate
the need for vehicle service for up to a year.
The engine oil and filter must be changed at
least once a year and the oil life system
must be reset. Your trained dealer technician
can perform this work. If the engine oil life
system is reset accidentally, service the
vehicle within 5 000 km/3,000 mi since the