2021 GMC SIERRA end cap

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
386 Vehicle Care
8. Remove any rust or dirt from the wheelbolts, mounting surfaces, and spare
wheel.
9. Install the spare tire.
{Warning
Never use oil or grease on bolts or nuts
because the nuts might come loose. The
vehicle's wheel could fall off, causing a
crash.
10. Put the wheel nuts back on with the rounded end of the nuts toward the
wheel. 11. Tighten each wheel nut by hand. Then
use the wheel wrench to tighten the
nuts until the wheel is held against
the hub.
12. Turn the wheel wrench counterclockwise to lower the vehicle. Lower the jack
completely.
{Warning
If wheel studs are damaged, they can
break. If all the studs on a wheel broke,
the wheel could come off and cause a
crash. If any stud is damaged because of
a loose-running wheel, it could be that all
of the studs are damaged. To be sure,
replace all studs on the wheel. If the stud
holes in a wheel have become larger, the
wheel could collapse in operation. Replace
any wheel if its stud holes have become
larger or distorted in any way. Inspect
hubs and hub‐piloted wheels for damage.
Because of loose running wheels, piloting
pad damage may occur and require
replacement of the entire hub, for proper
centering of the wheels. When replacing
studs, hubs, wheel nuts or wheels, be
sure to use GM original equipment parts.
{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
accessory locking wheel nuts. See
Capacities and Specifications 0424 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 0424 for the wheel nut
torque specification.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 387
13. Tighten the nuts firmly in a crisscrosssequence, as shown, by turning the
wheel wrench clockwise.
When reinstalling the regular wheel and tire,
also reinstall either the center cap,
or bolt-on hub cap, depending on what the
vehicle is equipped with. For center caps,
place the cap on the wheel and tap it into
place until it seats flush with the wheel. The
cap only goes on one way. Be sure to line
up the tab on the center cap with the
indentation on the wheel. For bolt-on hub
caps, align the plastic nut caps with the
wheel nuts and then tighten by hand. Then
use the wheel wrench to tighten.
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.
Caution
Storing an aluminum wheel with a flat
tire under your vehicle for an extended
period of time or with the valve stem
pointing up can damage the wheel.
Always stow the wheel with the valve
stem pointing down and have the wheel/
tire repaired as soon as possible.
Caution
The tire hoist can be damaged if there is
no tension on the cable when using it. To
have the necessary tension, the spare or
road tire and wheel assembly must be
installed on the tire hoist to use it.
{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.
Store the tire under the rear of the vehicle
in the spare tire carrier.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 395
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.
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.
.The towing capacity of the towing
vehicle. Read the tow vehicle
manufacturer's recommendations.
.How far the vehicle can be towed. Some
vehicles have restrictions on how far and
how long the vehicle can be towed.
.Whether the vehicle has the proper
towing equipment. See your dealer or
trailering professional for additional
advice and equipment recommendations.
.Whether the vehicle is ready to be towed.
Just as preparing the vehicle for a long
trip, make sure the vehicle is prepared to
be towed.
Follow the tow vehicle manufacturer’s
instructions. See your dealer or trailering
professional for additional advice and
equipment recommendations.
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.
Dinghy Towing (Two-Wheel-Drive
Vehicles and Vehicles with a
Single-Speed Transfer Case)
Caution
If a vehicle with two-wheel drive or a
single-speed transfer case 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 and vehicles with a
single-speed transfer case should not be
towed with all four wheels on the ground.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
400 Vehicle Care
The bright metal moldings on the vehicle
are aluminum, chrome or stainless steel. To
prevent damage always follow these
cleaning instructions:
.Be sure the molding is cool to the touch
before applying any cleaning solution.
.Use only approved cleaning solutions for
aluminum, chrome or stainless steel.
Some cleaners are highly acidic or contain
alkaline substances and can damage the
moldings.
.Always dilute a concentrated cleaner
according to the manufacturer’s
instructions.
.Do not use cleaners that are not intended
for automotive use.
.Use a nonabrasive wax on the vehicle
after washing to protect and extend the
molding finish.
Spray-In Bedliner Care
Caution
Using silicone-based products may
damage the bedliner, reduce the
slip-resistant texture, and attract dirt. A spray-in bedliner is a permanent coating
that bonds to the truck bed and cannot be
removed. Promptly rinse the bedliner surface
following a chemical spill to avoid
permanent damage.
Spray-in bedliners can fade from oxidation,
road dirt, heavy-duty hauling, and hard
water stains. Clean it periodically by
washing off the loose dirt and using a mild
detergent. To restore the original
appearance, apply the bedliner conditioner
available through your dealer.
CarbonPro Box Care
Caution
To prevent surface damage to the pickup
box, rinse chemical spills quickly, never
use alcohol wipes to clean, and avoid
scraping the surface.
If equipped with a CarbonPro Pickup Box,
use the following instructions for cleaning:
.Clean the box periodically by washing off
the loose dirt with water and a mild
detergent.
.Promptly rinse the bed surface following
a chemical spill to avoid permanent
damage.
.Use a dry rag to remove oil.
Cleaning Exterior Lamps/Lenses,
Emblems, Decals and Stripes
Use only lukewarm or cold water, a soft
cloth, and a car washing soap to clean
exterior lamps, lenses, emblems, decals and
stripes. Follow instructions under "Washing
the Vehicle" previously in this section.
Lamp covers are made of plastic, and some
have a UV protective coating. Do not clean
or wipe them while they are dry.
Do not use any of the following on lamp
covers:
.Abrasive or caustic agents.
.Washer fluids and other cleaning agents
in higher concentrations than suggested
by the manufacturer.
.Solvents, alcohols, fuels, or other harsh
cleaners.
.Ice scrapers or other hard items.
.Aftermarket appearance caps or covers
while the lamps are illuminated, due to
excessive heat generated.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
424 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and Lubricants0418.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Application Capacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and charge amount, see the refrigerant label under the hood. See yourdealer for more information.
Engine Cooling System*
I2.7L L4 Engine (L3B) 11.8 L 12.4 qt
I4.3L V6 Engine (LV3) 11.5 L 12.2 qt
I5.3L V8 Engine (L82) 12.8 L 13.5 qt
I5.3L V8 Engine (L84) 13.1 L 13.8 qt
I6.2L V8 Engine (L87) 12.6 L 13.3 qt

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
426 Technical Data
ApplicationCapacities
Metric English
Transfer Case Fluid 1.5 L 1.6 qt
Wheel Nut Torque 190 Y140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
2.7L L4 (L3B) K0.65–0.75 mm (0.026–0.030 in)
4.3L V6 (LV3) H0.95–1.10 mm (0.037–0.043 in)
5.3L V8 (L82) F0.95–1.10 mm (0.037–0.043 in)
5.3L V8 (L84) D0.95–1.10 mm (0.037–0.043 in)
6.2L V8 (L87) L0.95–1.10 mm (0.037–0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
442 OnStar
Reactivation for Subsequent Owners
PressQand follow the prompts to speak to
an Advisor as soon as possible. The Advisor
will update vehicle records and explain
OnStar or connected service options.
How OnStar Service Works
Automatic Crash Response, Emergency
Services, Crisis Assist, Stolen Vehicle
Assistance, Remote Services, and Roadside
Assistance are available on most vehicles.
Not all OnStar services are available
everywhere or on all vehicles. For more
information, a full description of OnStar
services, system limitations, and OnStar User
Terms, Privacy Statement, and Software
Terms:
.Call 1-888-4ONSTAR (1-888-466-7827).
.See www.onstar.com (U.S.).
.See www.onstar.ca (Canada).
.Call TTY 1-877-248-2080.
.PressQto speak with an Advisor.
OnStar or connected services cannot work
unless the vehicle is in a place where OnStar
has an agreement with a wireless service
provider for service in that area. The
wireless service provider must also have
coverage, network capacity, reception, and technology compatible with OnStar or
connected services. Service involving location
information about the vehicle cannot work
unless GPS signals are available,
unobstructed, and compatible with the
OnStar hardware. OnStar or connected
services may not work if the OnStar
equipment is not properly installed or it has
not been properly maintained. If equipment
or software is added, connected,
or modified, OnStar or connected services
may not work. Other problems beyond the
control of OnStar
—such as hills, tall
buildings, tunnels, weather, electrical system
design and architecture of the vehicle,
damage to the vehicle in a crash, or wireless
phone network congestion or jamming —
may prevent service.
See Radio Frequency Statement 0436.
Services for People with Disabilities
Advisors provide services to help with
physical disabilities and medical conditions.
Press
Qto help:
.Locate a gas station with an attendant to
pump gas.
.Find a hotel, restaurant, etc., that meets
accessibility needs.
.Provide directions to the closest hospital
or pharmacy in urgent situations.
TTY Users
OnStar has the ability to communicate to
deaf, hard-of-hearing, or speech-impaired
customers while in the vehicle. The available
dealer-installed TTY system can provide
in-vehicle access to all OnStar services,
except Virtual Advisor and OnStar
Turn-by-Turn Navigation.
If equipped, TTY mode can be turned on or
off by touching Settings, then Apps, and
then Phone. When TTY mode is on, phone
calls can be made or received with OnStar
using the infotainment display.
OnStar Personal Identification
Number (PIN)
A PIN is needed to access some OnStar
services. The PIN will need to be changed
the first time when speaking with an
Advisor. To change the OnStar PIN, contact
an OnStar Advisor by pressing
Qor calling
1-888-4ONSTAR.
Warranty
OnStar equipment may be warranted as part
of the vehicle warranty.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
OnStar 443
Languages
The vehicle can be programmed to respond
in multiple languages. Press
Qand ask for
an Advisor. Advisors are available in English,
Spanish, and French. Available languages
may vary by country.
Potential Issues
OnStar cannot perform Remote Door Unlock
or Stolen Vehicle Assistance after the vehicle
has been off continuously for 10 days
without an ignition cycle. If the vehicle has
not been started for 10 days, OnStar can
contact Roadside Assistance or a locksmith
to help gain access to the vehicle.
Global Positioning System (GPS)
.Obstruction of the GPS can occur in a
large city with tall buildings; in parking
garages; around airports; in tunnels and
underpasses; or in an area with very
dense trees. If GPS signals are not
available, the OnStar system should still
operate to call OnStar. However, OnStar
could have difficulty identifying the exact
location.
.In emergency situations, OnStar can use
the last stored GPS location to send to
emergency responders. A temporary loss of GPS can cause loss of
the ability to send a Turn-by-Turn
Navigation route. The Advisor may give a
verbal route or may ask for a call back after
the vehicle is driven into an open area.
Cellular and GPS Antennas
Cellular reception is required for OnStar to
send remote signals to the vehicle. Do not
place items over or near the antenna to
prevent blocking cellular and GPS signal
reception.
Unable to Connect to OnStar Message
If there is limited cellular coverage or the
cellular network has reached maximum
capacity, this message may come on. Press
Qto try the call again or try again after
driving a few miles into another
cellular area.
Vehicle and Power Issues
OnStar services require a vehicle electrical
system, wireless service, and GPS satellite
technologies to be available and operating
for features to function properly. These
systems may not operate if the battery is
discharged or disconnected.
Add-on Electrical Equipment
The OnStar system is integrated into the
electrical architecture of the vehicle. Do not
add any electrical equipment. See Add-On
Electrical Equipment 0318. Added electrical
equipment may interfere with the operation
of the OnStar system and cause it to not
operate.
Vehicle Software Updates
OnStar or GM may remotely deliver
software updates or changes to the vehicle
without further notice or consent. These
updates or changes may enhance or
maintain safety, security, or the operation
of the vehicle or the vehicle systems.
Software updates or changes may affect or
erase data or settings that are stored in the
vehicle, such as saved navigation
destinations or pre-set radio stations.
Neither OnStar nor GM is responsible for
any affected or erased data or settings.
These updates or changes may also collect
personal information. Such collection is
described in the OnStar privacy statement or
separately disclosed at the time of
installation. These updates or changes may
also cause a system to automatically
communicate with GM servers to collect
information about vehicle system status,