trailer GMC YUKON 2021 Repair Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 335
FusesUsage
69 Starter pinion 71 Cool fan motor lower
72 Right cool fan motor/ Lower
73 Left trailer stop turn lamp
74 TIM 2 75 DEFC
76 ELEC RNG BDS
78 ECM
79 –
80 Cabin cool pump 17W 81 Right trailer stop turn lamp
82 TIM 1
83 FTZM
84 Trailer battery 85 Engine
86 ECM 87 Injector B even
88 02 B sensor Fuses
Usage
89 02 A sensor
90 Injector A odd 91 ECM throttle control
92 Cool fan clutch AERO shutter
Relays Usage
5 –
18 DC/AC inverter
23 –
35 Park lamp
36 Run/Crank
43 Secondary axle motor
59 A/C clutch
64 Starter motor 70 Starter pinion 77 PowertrainInstrument Panel Fuse Block
The right instrument panel fuse block access
door is on the passenger side edge of the
instrument panel.
Pull off the cover to access the fuse block.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
342 Vehicle Care
(8) Temporary Use Only:Only use a
temporary spare tire until the road tire
is repaired and replaced. This spare tire
should not be driven on over 112 km/h
(70 mph), or 88 km/h (55 mph) when
pulling a trailer, with the proper
inflation pressure. See Full-Size Spare
Tire 0366.
Tire Designations
Tire Size
The example shows a typical passenger
vehicle tire size.
Passenger (P-Metric) Tire
(1) Passenger (P-Metric) Tire:The
United States version of a metric tire
sizing system. The letter "P" as the first
character in the tire size means a passenger vehicle tire engineered to
standards set by the U.S. Tire and Rim
Association.
(2) Tire Width
:The 3-digit number
indicates the tire section width in
millimeters from sidewall to sidewall.
(3) Aspect Ratio
:A 2-digit number that
indicates the tire height-to-width
measurements. For example, if the tire
size aspect ratio is 75, as shown in
item (3) of the illustration, it would
mean that the tire's sidewall is
75 percent as high as it is wide.
(4) Construction Code
:A letter code is
used to indicate the type of ply
construction in the tire. The letter "R"
means radial ply construction; the letter
"D" means diagonal or bias ply
construction.
(5) Rim Diameter
:Diameter of the
wheel in inches.
(6) Service Description
:These
characters represent the load index and
speed rating of the tire. The load index
represents the load carrying capacity a tire is certified to carry. The speed
rating is the maximum speed a tire is
certified to carry a load.
Tire Terminology and Definitions
Air Pressure:The amount of air inside
the tire pressing outward on each
square inch of the tire. Air pressure is
expressed in kPa (kilopascal) or psi
(pounds per square inch).
Accessory Weight
:The combined
weight of optional accessories. Some
examples of optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship of a
tire's height to its width.
Belt
:A rubber coated layer of cords
between the plies and the tread. Cords
may be made from steel or other
reinforcing materials.
Bead
:The tire bead contains steel
wires wrapped by steel cords that hold
the tire onto the rim.

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
Vehicle Care 371
GM recommends a flatbed tow truck to
transport a disabled vehicle. Use ramps to
help reduce approach angles, if necessary.
A towed vehicle should have its drive wheels
off the ground. Contact Roadside Assistance
or a professional towing service if the
disabled vehicle must be towed.
Front Attachment Points
The vehicle is equipped with specific
attachment points to be used to pull the
vehicle onto a flatbed car carrier from a flat
road surface. Do not use these attachment
points to pull the vehicle from snow, mud
or sand.
Recreational Vehicle Towing
Recreational vehicle towing means towing
the vehicle behind another vehicle, such as a
motor home. The two most common types
of recreational vehicle towing are dinghy
and dolly towing. Dinghy towing is towing
the vehicle with all four wheels on the
ground. Dolly towing is towing the vehicle
with two wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle manufacturer’s
instructions. See your dealer or trailering
professional for additional advice and
equipment recommendations.
Here are some important things to consider
before recreational vehicle towing:
.Before towing the vehicle, become
familiar with the local laws that apply to
recreational vehicle towing. These laws
may vary by region.
.What is the towing capacity of the
towing vehicle? Be sure to read the tow
vehicle manufacturer's recommendations.
.What is the distance that will be
traveled? Some vehicles have restrictions
on how far and how long they can tow.
.Is the proper towing equipment going to
be used? See your dealer or trailering
professional for additional advice and
equipment recommendations.
.Is the vehicle ready to be towed? Just as
preparing the vehicle for a long trip,
make sure the vehicle is prepared to be
towed.
Caution
Use of a shield mounted in front of the
vehicle grille could restrict airflow and
cause damage to the transmission. The
repairs would not be covered by the
vehicle warranty. If using a shield, only
use one that attaches to the towing
vehicle.

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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13690468) - 2021 - crc - 8/14/20
428 Index
Tires (cont'd)Pressure Light . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Pressure Monitor Operation . . . . . . . . . . . 347
Pressure Monitor System . . . . . . . . . . . . . . 346
Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Sidewall Labeling . . . . . . . . . . . . . . . . . . . . . . 341
Terminology and Definitions . . . . . . . . . . . 342
Uniform Tire Quality Grading . . . . . . . . . . 353
Wheel Alignment and Tire Balance . . . . 354
Wheel Replacement . . . . . . . . . . . . . . . . . . . . 354
When It Is Time for New Tires . . . . . . . . . 351
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . . . 235
Towing Driving Characteristics . . . . . . . . . . . . . . . . . 280
Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
General Information . . . . . . . . . . . . . . . . . . . 280
Recreational Vehicle . . . . . . . . . . . . . . . . . . . . 371
Trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Trailer Sway Control (TSC) . . . . . . . . . . . . . 295
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Traction Control/Electronic Stability Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Trademarks and License Agreements . . . . . 196 Trailer
Sway Control (TSC) . . . . . . . . . . . . . . . . . . . . 295
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Trailer Towing App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Transfer Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Transmission Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Fluid, Automatic . . . . . . . . . . . . . . . . . . . . . . . . 317
Transportation Program, Courtesy . . . . . . . 404
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Turn and Lane-Change Signals . . . . . . . . . . . .138
U
Uniform Tire Quality Grading . . . . . . . . . . . . 353
Universal Remote System . . . . . . . . . . . . . . . . . 131
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Updates Map Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
USB Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Using the Navigation System . . . . . . . . . . . . 164
Using the System . . . . . . . . . . . . . . . . . . . . . . . . .145
Using This Manual . . . . . . . . . . . . . . . . . . . . . . . . . .2
V
Vehicle Alarm System . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Canadian Owners . . . . . . . . . . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Identification Number (VIN) . . . . . . . . . . . . 396
Load Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Personalization . . . . . . . . . . . . . . . . . . . . . . . . 126
Remote Start . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Speed Messages . . . . . . . . . . . . . . . . . . . . . . . 126
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . . . . 115
Vehicle Care
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Vehicle Data Recording and Privacy . . . . . . 408
Vehicle Positioning . . . . . . . . . . . . . . . . . . . . . . . 175
Vehicle Security Steering Column Lock . . . . . . . . . . . . . . . . . . . 27
Ventilation, Air . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Voice Recognition . . . . . . . . . . . . . . . . . . . . . . . . 176
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . . . 108
W
Warning Brake System Light . . . . . . . . . . . . . . . . . . . . . 112