width GMC SIERRA 2021 Owner's Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
30 Keys, Doors, and Windows
When applying any load to the tailgate,
distribute the weight evenly across the
width of the tailgate. This applies to all
tailgate types.
.Use a load-distributing member (1).
.Secure the ramp to the bumper (2).
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, when
enabled, will extend when the door is
opened. They will retract three seconds after
the door is closed or immediately if the
vehicle starts moving.
Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse direction if there is an
obstruction. If possible, carefully remove the
obstruction, then open and close the door
on the same side to complete the motion.
If the obstruction is not cleared, the assist
steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park) and unlock
the doors. 2. Kick the switch to extend the power
assist step to the tire. A Driver
Information Center (DIC) message
displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be extended to
the tire by pressing
j. When extending
the steps with
j, the kick switch is
disabled. The vehicle must be in P (Park) or
N (Neutral).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 225
the actual loads on the front and rear
axles, weigh the vehicle at a weigh
station. Your dealer can help with this.
Be sure to spread the load equally on
both sides of the centerline.
The Certification/Tire label also contains
important information about the Front
Axle Reserve Capacity. SeeAdding a
Snow Plow or Similar Equipment 0318.
{Warning
In the case of a sudden stop or
collision, things carried in the bed of
your truck could shift forward and
come into the passenger area,
injuring you and others. If you put
things in the bed of your truck, you
should make sure they are properly
secured.
Caution
Overloading the vehicle may cause
damage. Repairs would not be covered by
the vehicle warranty. Do not overload the
vehicle.
Using heavier suspension components
to get added durability might not
change the weight ratings. Ask your
dealer to help load the vehicle the
right way.
{Warning
Things you put inside the vehicle can
strike and injure people in a sudden
stop or turn, or in a crash.
.Put things in the cargo area of the
vehicle. Try to spread the weight
evenly.
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.When you carry something inside
the vehicle, secure it whenever
you can.
.Do not leave a seat folded down
unless you need to. There is also important loading
information for off-road driving in this
manual. See
“Loading the Vehicle for
Off-Road Driving“ underOff-Road
Driving 0215.
Two-Tiered Loading
Depending on the model of the pickup,
an upper load platform can be created
by positioning three or four 5 cm (2 in)
by 15 cm (6 in) wooden planks across
the width of the pickup box. The planks
must be inserted in the pickup box
depressions.
When using this upper load platform,
be sure the load is securely tied down
to prevent it from shifting. The load's
center of gravity should be positioned
in a zone over the rear axle. The zone is
located in the area between the front
of each wheel well and the rear of each
wheel well. The center of gravity height
must not extend above the top of the
pickup box flareboard.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
310 Driving and Operating
The process stops without saving the
sensor locations if this step takes more
than two minutes.
4. Move to the next tire and repeat Step 3 for each sensor. The horn chirps twice
when all sensors are completed.
5. Return to the vehicle to complete the setup.
Maintenance Reminders
To set up maintenance reminders, touch the
Trailer Maintenance icon. Select Yes to set
up the maintenance reminders for the
Trailer Profile. Follow the on-screen prompts.
The maximum number of reminders is 50.
Select No to return to the previous screen.
Towing Assistance
To set up towing assistance features,
if equipped, touch the Towing
Assistance icon.
Touch Yes to begin set up or touch No to
return to the previous screen.
1. Select the number of axles on the trailer.
2. Enter trailer dimensions as prompted.
3. Follow the on-screen instructions to complete setup for available features.
Transparent Trailer Setup (if equipped)
To complete setup for transparent trailer:
.Trailer Length: 300 cm (118.1 in) –970 cm
(381.8 in). Measure from center of coupler
to furthest rear point on the trailer.
.Trailer Width: 120 cm (47.2 in) –260 cm
(102.3 in). Measure from left edge to
right edge.
.Trailer Height: 1 cm (0.39 in) –450 cm
(177.1 in). Measure from ground to tallest
point.
.Hitching Point Length: 180 cm (70.8 in) –
970 cm (381.8 in). Measure from center of
coupler to middle of tires.
.Trailer Tongue Length: 50 cm (19.6 in) –
220 cm (86.6 in). Measure from center of
coupler to trailer front wall.
.Vehicle Hitch Height: 10 cm (3.9 in) –
100 cm (39.3 in). Measure from ground to
top of coupler.
.Vehicle Hitch Length: 10 cm (3.9 in) –
100 cm (39.3 in). Measure from hitch
receiver to center of ball.
1. If trailer dimensions are out of range, this feature will be unavailable.
2. Ensure rear trailer camera is connected. 3. Follow instructions to drive forward to
complete calibration.
Rear Trailer Guidance Setup (if equipped)
A rear trailer camera must be mounted on
the trailer and electrically connected to the
vehicle before transparent trailer feature can
be used. See Assistance Systems for Parking
or Backing 0266.
Trailer dimensions must be in range to
enable this feature.
.Trailer Length: 300 cm (118.1 in) –970 cm
(381.8 in). Measure from center of coupler
to furthest rear point on the trailer.
1. If trailer dimensions are out of range, this feature will be unavailable.
2. Ensure rear trailer camera is connected.
3. Follow instructions to drive forward to complete calibration.
Jack-Knife Alert Setup (if equipped)
Follow instructions to drive forward to
complete calibration.
Trailer Length Indicator Setup (if
equipped)
Follow instructions to drive forward to
complete calibration.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
362 Vehicle Care
If using winter tires:
.Use tires of the same brand and tread
type on all four wheel positions.
.Use only radial ply tires of the same size,
load range, and speed rating as the
original equipment tires.
Winter tires with the same speed rating as
the original equipment tires may not be
available for H, V, W, Y, and ZR speed rated
tires. If winter tires with a lower speed
rating are chosen, never exceed the tire's
maximum speed capability.
All-Terrain Tires
This vehicle may have all-terrain or
mud-terrain tires. These tires provide good
performance on most road surfaces, weather
conditions, and for off-road driving. See
Off-Road Driving 0215.
The tread pattern on these tires may wear
more unevenly than other tires. Consider
rotating the tires more frequently than at
12 000 km (7,500 mi) intervals if irregular
wear is noted when the tires are inspected.
See Tire Inspection 0373.
Tire Sidewall Labeling
Useful information about a tire is
molded into the sidewall. The examples
show a typical passenger and light
truck tire sidewall.
Passenger (P-Metric)/Spare Tire
(1) Tire Size:The tire size code is a
combination of letters and numbers
used to define a particular tire's width,
height, aspect ratio, construction type,
and service description. See the “Tire
Size” illustration later in this section. (2) TPC Spec (Tire Performance Criteria
Specification)
:Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. GM's TPC specifications meet
or exceed all federal safety guidelines.
(3) DOT (Department of
Transportation)
:The Department of
Transportation (DOT) code indicates that
the tire is in compliance with the U.S.
Department of Transportation Motor
Vehicle Safety Standards.
DOT Tire Date of Manufacture
:The last
four digits of the TIN indicate the tire
manufactured date. The first two digits
represent the week (01-52) and the last
two digits, the year. For example, the
third week of the year 2020 would have
a 4-digit DOT date of 0320. Week 01 is
the first full week (Sunday through
Saturday) of each year.
(4) Tire Identification Number (TIN)
:
The letters and numbers following the
DOT code are the Tire Identification
Number (TIN). The TIN shows the

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Vehicle Care 363
manufacturer and plant code, tire size,
and date the tire was manufactured.
The TIN is molded onto both sides of
the tire, although only one side may
have the date of manufacture.
(5) Tire Ply Material
:The type of cord
and number of plies in the sidewall and
under the tread.
(6) Uniform Tire Quality Grading
(UTQG)
:Tire manufacturers are
required to grade tires based on three
performance factors: treadwear,
traction, and temperature resistance.
For more information, see Uniform Tire
Quality Grading 0377.
(7) Maximum Cold Inflation Load
Limit
:Maximum load that can be
carried and the maximum pressure
needed to support that load. For
information on recommended tire
pressure see Tire Pressure 0367 and
Vehicle Load Limits 0222.
(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 0390.
Light Truck (LT-Metric) Tire
(1) Tire Size:The tire size code is a
combination of letters and numbers
used to define a particular tire's width,
height, aspect ratio, construction type,
and service description. See the “Tire
Size” illustration later in this section for
more detail.
(2) TPC Spec (Tire Performance Criteria
Specification)
:Original equipment tires
designed to GM's specific tire performance criteria have a TPC
specification code molded onto the
sidewall. GM's TPC specifications meet
or exceed all federal safety guidelines.
(3) Dual Tire Maximum Load
:
Maximum load that can be carried and
the maximum pressure needed to
support that load when used in a dual
configuration. For information on
recommended tire pressure see
Tire
Pressure 0367 and
Vehicle Load Limits 0222.
(4) DOT (Department of
Transportation)
:The Department of
Transportation (DOT) code indicates that
the tire is in compliance with the U.S.
Department of Transportation Motor
Vehicle Safety Standards.
DOT Tire Date of Manufacture
:The last
four digits of the TIN indicate the tire
manufactured date. The first two digits
represent the week (01-52) and the last
two digits, the year. For example, the
third week of the year 2020 would have

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
364 Vehicle Care
a 4-digit DOT date of 0320. Week 01 is
the first full week (Sunday through
Saturday) of each year.
(5) Tire Identification Number (TIN)
:
The letters and numbers following the
DOT code are the Tire Identification
Number (TIN). The TIN shows the
manufacturer and plant code, tire size,
and date the tire was manufactured.
The TIN is molded onto both sides of
the tire, although only one side may
have the date of manufacture.
(6) Tire Ply Material
:The type of cord
and number of plies in the sidewall and
under the tread.
(7) Single Tire Maximum Load
:
Maximum load that can be carried and
the maximum pressure needed to
support that load when used as a
single. For information on
recommended tire pressure see Tire
Pressure 0367 and
Vehicle Load Limits 0222.
Tire Designations
Tire Size
The examples show a typical passenger
vehicle and light truck 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 tire 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.
Light Truck (LT-Metric) Tire

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 365
(1) Light Truck (LT-Metric) Tire:The
United States version of a metric tire
sizing system. The letters LT as the first
two characters in the tire size mean a
light truck 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 light truck (LT-Metric) tire
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) Load Range
:Load Range.
(7) Service Description
:The service
description indicates the load index and
speed rating of a tire. If two numbers
are given as in the example, 120/116,
then this represents the load index for
single versus dual wheel usage (single/
dual). 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.
Bias Ply Tire
:A pneumatic tire in which
the plies are laid at alternate angles
less than 90 degrees to the centerline
of the tread.
Cold Tire Pressure
:The amount of air
pressure in a tire, measured in kPa
(kilopascal) or psi (pounds per square
inch) before a tire has built up heat
from driving. See Tire Pressure0367.
Curb Weight
:The weight of a motor
vehicle with standard and optional
equipment including the maximum
capacity of fuel, oil, and coolant, but
without passengers and cargo.
DOT Markings
:A code molded into the
sidewall of a tire signifying that the tire
is in compliance with the U.S.
Department of Transportation (DOT)

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Vehicle Care 377
If the vehicle tires must be replaced
with a tire that does not have a TPC
Spec number, make sure they are the
same size, load range, speed rating, and
construction (radial) as the original
tires.
The Tire and Loading Information label
indicates the original equipment tires
on the vehicle. SeeVehicle Load Limits
0 222.
Different Size Tires and Wheels
If wheels or tires are installed that are a
different size than the original equipment
wheels and tires, vehicle performance,
including its braking, ride and handling
characteristics, stability, and resistance to
rollover may be affected. If the vehicle has
electronic systems such as antilock brakes,
rollover airbags, traction control, electronic
stability control, or All-Wheel Drive, the
performance of these systems can also be
affected.
{Warning
If different sized wheels are used, there
may not be an acceptable level of
performance and safety if tires not
recommended for those wheels are
selected. This increases the chance of a
crash and serious injury. Only use GM
specific wheel and tire systems developed
for the vehicle, and have them properly
installed by a GM certified technician.
See Buying New Tires 0376 and
Accessories and Modifications 0323.
Uniform Tire Quality Grading
The following information relates to the
system developed by the United States
National Highway Traffic Safety
Administration (NHTSA), which grades
tires by treadwear, traction, and
temperature performance. This applies
only to vehicles sold in the United
States. The grades are molded on the
sidewalls of most passenger car tires.
The Uniform Tire Quality Grading
(UTQG) system does not apply to deep
tread, winter tires, compact spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General
Motors passenger cars and light trucks
may vary with respect to these grades,
they must also conform to federal
safety requirements and additional
General Motors Tire Performance
Criteria (TPC) standards.
Quality grades can be found where
applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:Treadwear 200 Traction AA Temperature A
All Passenger Car Tires Must Conform to
Federal Safety Requirements In Addition
To These Grades.
Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the
tire when tested under controlled
conditions on a specified government
test course. For example, a tire graded
150 would wear one and one-half (1½)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Vehicle Care 379
Your dealer will know the kind of wheel that
is needed.
Each new wheel should have the same
load-carrying capacity, diameter, width,
offset, and be mounted the same way as
the one it replaces.
Replace wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System (TPMS)
sensors with new GM original equipment
parts.
{Warning
Using the wrong replacement wheels,
wheel bolts, or wheel nuts can be
dangerous. It could affect the braking and
handling of the vehicle. Tires can lose air,
and cause loss of control, causing a crash.
Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle
ground clearance, and tire or tire chain
clearance to the body and chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used one is
dangerous. How it has been used or how
far it has been driven may be unknown.
It could fail suddenly and cause a crash.
When replacing wheels, use a new GM
original equipment wheel.
Tire Chains
{Warning
If the vehicle has 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
size tires, do not use tire chains. There is
not enough clearance. Tire chains used on
a vehicle without the proper amount of
clearance can cause damage to the
brakes, suspension, or other vehicle parts.
The area damaged by the tire chains
could cause loss of control and a crash.
Use another type of traction device only
if its manufacturer recommends it for the
vehicle's tire size combination and road
conditions. Follow that manufacturer's(Continued)
Warning (Continued)
instructions. To avoid vehicle damage,
drive slow and readjust or remove the
traction device if it is contacting the
vehicle. Do not spin the wheels.
If traction devices are used, install them
on the rear tires.
Caution
If the vehicle is equipped with a tire size
other than 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
use tire chains only where legal and only
when necessary. Use chains that are the
proper size for the tires. Install them on
the tires of the rear axle. Do not use
chains on the tires of the front axle.
Tighten them as tightly as possible with
the ends securely fastened. Drive slowly
and follow the chain manufacturer's
instructions. If the chains contact the
vehicle, stop and retighten them. If the
contact continues, slow down until it
stops. Driving too fast or spinning the
wheels with chains on will damage the
vehicle.