
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 301
E85 or FlexFuel should meet
ASTM Specification D 5798 or
CAN/CGSB–3.512 in Canada. Do
not use the fuel if the ethanol
content is greater than 85%. Fuel
mixtures that do not meet ASTM or
CGSB specifications can affect
driveability and could cause the
malfunction indicator lamp to
come on.
For the 6.0L V8 engine, after
refueling, the vehicle calculates the
composition of the fuel. It is not
recommended to repeatedly switch
between fuels. If fuels are switched
frequently, add as much fuel as
possible and do not add less than
11 L (3 gal) when refueling. Drive at
least 11 km (7 mi) immediately after
refueling to allow the vehicle to
adapt to the change in ethanol
concentration.
Because E85 or FlexFuel has less
energy per liter (gallon) than
gasoline, the vehicle will need to be
refilled more often. SeeFilling the
Tank 0301.Caution
Some additives are not
compatible with E85 or FlexFuel
and can harm the vehicle's fuel
system. Do not add anything to
E85 or FlexFuel. Damage caused
by additives would not be covered
by the vehicle warranty.
Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Filling the Tank
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
. To help avoid injuries to you
and others, read and follow
all the instructions on the
fuel pump island.
. Turn off the engine when
refueling.
. Keep sparks, flames, and
smoking materials away
from fuel.
. Do not leave the fuel pump
unattended.
. Do not use a cell phone
while refueling.
. Do not reenter the vehicle
while pumping fuel.
. Keep children away from
the fuel pump and never let
children pump fuel.
(Continued)

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Driving and Operating 303
{Warning
Attempting to refuel without using
the funnel adapter may cause fuel
spillage and damage the capless
fuel system. This could cause a
fire and you or others could be
badly burned and the vehicle
could be damaged.
3. Remove and clean the funnel adapter and return to the
storage location.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
(Continued)
Warning (Continued)
.Use approved fuel
containers.
. Remove the container from
the vehicle, trunk, or pickup
bed before filling.
. Place the container on the
ground.
. Place the nozzle inside the
fill opening of the container
before dispensing fuel, and
keep it in contact with the fill
opening until filling is
complete.
. Fill the container no more
than 95% full to allow for
expansion.
. Do not smoke, light
matches, or use lighters
while pumping fuel.
. Avoid using cell phones or
other electronic devices.
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle 0430. For
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing 0430.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.
Become familiar with the state
and local laws that apply to
trailer towing.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Customer Information 465
Customer
Information
Customer Information
Customer SatisfactionProcedure . . . . . . . . . . . . . . . . . . . 465
Customer Assistance Offices . . . . . . . . . . . . . . . . . . . . . . 467
Customer Assistance for Text Telephone (TTY) Users . . . . . 468
Online Owner Center . . . . . . . . . 468
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . 469
Roadside Assistance Program . . . . . . . . . . . . . . . . . . . . 469
Scheduling Service Appointments . . . . . . . . . . . . . . . 471
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . 471
Collision Damage Repair . . . . . 472
Service Publications Ordering Information . . . . . . . . . . . . . . . . . . 474
Radio Frequency Statement . . . . . . . . . . . . . . . . . . . 475
Reporting Safety Defects
Reporting Safety Defects tothe United States
Government . . . . . . . . . . . . . . . . . 476
Reporting Safety Defects to the Canadian
Government . . . . . . . . . . . . . . . . . 476
Reporting Safety Defects to General Motors . . . . . . . . . . . . . 477
Vehicle Data Recording and
Privacy
Vehicle Data Recording andPrivacy . . . . . . . . . . . . . . . . . . . . . . 477
Event Data Recorders . . . . . . . . 477
OnStar . . . . . . . . . . . . . . . . . . . . . . . 478
Infotainment System . . . . . . . . . . 478
Customer Information
Customer Satisfaction
Procedure
Your satisfaction and goodwill are
important to your dealer and to
GMC. Normally, any concerns with
the sales transaction or the
operation of the vehicle will be
resolved by your dealer's sales or
service departments. Sometimes,
however, despite the best intentions
of all concerned, misunderstandings
can occur. If your concern has not
been resolved to your satisfaction,
the following steps should be taken:
STEP ONE : Discuss your concern
with a member of dealership
management. Normally, concerns
can be quickly resolved at that level.
If the matter has already been
reviewed with the sales, service,
or parts manager, contact the owner
of your dealership or the general
manager.
STEP TWO : If after contacting a
member of dealership management,
it appears your concern cannot be

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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466 Customer Information
resolved by your dealership without
further help, in the U.S., call
1-800-462-8782. In Canada, call
General Motors of Canada
Customer Care Centre at
1-800-263-3777 (English),
or 1-800-263-7854 (French).
We encourage you to call the
toll-free number in order to give your
inquiry prompt attention. Have the
following information available to
give the Customer Assistance
representative:
.Vehicle Identification
Number (VIN). This is available
from the vehicle registration or
title, or the plate at the top left of
the instrument panel and visible
through the windshield.
. Dealership name and location.
. Vehicle delivery date and
present mileage.
When contacting GMC, remember
that your concern will likely be
resolved at a dealer's facility. That is
why we suggest following Step One
first. STEP THREE
—U.S. Owners :
Both General Motors and your
dealer are committed to making
sure you are completely satisfied
with your new vehicle. However,
if you continue to remain unsatisfied
after following the procedure
outlined in Steps One and Two, you
can file with the Better Business
Bureau (BBB) Auto Line Program to
enforce your rights.
The BBB Auto Line Program is an
out-of-court program administered
by the Council of Better Business
Bureaus to settle automotive
disputes regarding vehicle repairs or
the interpretation of the New Vehicle
Limited Warranty. Although you may
be required to resort to this informal
dispute resolution program prior to
filing a court action, use of the
program is free of charge and your
case will generally be heard within
40 days. If you do not agree with the
decision given in your case, you
may reject it and proceed with any
other venue for relief available
to you. You may contact the BBB Auto Line
Program using the toll-free
telephone number or write them at
the following address:
BBB Auto Line Program
Council of Better Business Bureaus,
Inc.
3033 Wilson Blvd.
Suite 600
Arlington, VA 22201
Telephone: 1-800-955-5100
http://www.bbb.org/council/
programs-services/
dispute-handling-and-resolution/
bbb-auto-line
This program is available in all
50 states and the District of
Columbia. Eligibility is limited by
vehicle age, mileage, and other
factors. General Motors reserves
the right to change eligibility
limitations and/or discontinue its
participation in this program.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Customer Information 467
STEP THREE—Canadian
Owners : In the event that you do
not feel your concerns have been
addressed after following the
procedure outlined in Steps One
and Two, General Motors of Canada
Company wants you to be aware of
its participation in a no-charge
Mediation/Arbitration Program.
General Motors of Canada
Company has committed to binding
arbitration of owner disputes
involving factory-related vehicle
service claims. The program
provides for the review of the facts
involved by an impartial third party
arbiter, and may include an informal
hearing before the arbiter. The
program is designed so that the
entire dispute settlement process,
from the time you file your complaint
to the final decision, should be
completed in about 70 days. We
believe our impartial program offers
advantages over courts in most
jurisdictions because it is informal,
quick, and free of charge. For further information concerning
eligibility in the Canadian Motor
Vehicle Arbitration Plan (CAMVAP),
call toll-free 1-800-207-0685, or call
the General Motors Customer Care
Centre, 1-800-263-3777 (English),
1-800-263-7854 (French),
or write to:
Mediation/Arbitration Program
c/o Customer Care Centre
General Motors of Canada
Company
Mail Code: CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Your inquiry should be accompanied
by the Vehicle Identification
Number (VIN).
Customer Assistance
Offices
GMC encourages customers to call
the toll-free number for assistance.
However, if a customer wishes to
write or e-mail GMC, the letter
should be addressed to:
United States and Puerto Rico
GMC Customer Assistance Center
P.O. Box 33172
Detroit, MI 48232-5172
www.GMC.com
1-800-GMC-8782 (1-800-462-8782)
1-888-889-2438 (For Text
Telephone devices (TTYs))
Roadside Assistance:
1-888-881-3302
From U.S. Virgin Islands:
1-800-496-9994
Canada
General Motors of Canada
Company
Customer Care Centre,
Mail Code: CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
www.gmc.ca
1-800-263-3777 (English)
1-800-263-7854 (French)
1-800-263-3830 (For Text
Telephone Devices (TTYs))
Roadside Assistance:
1-800-268-6800

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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468 Customer Information
Overseas
Please contact the local General
Motors Business Unit.
Customer Assistance for
Text Telephone (TTY)
Users
To assist customers who are deaf,
hard of hearing, or speech-impaired
and who use Text Telephones
(TTYs), GMC has TTY equipment
available at its Customer Assistance
Center. Any TTY user in the U.S.
can communicate with GMC by
dialing: 1-888-889-2438. TTY users
in Canada can dial 1-800-263-3830.
Online Owner Center
Online Owner Experience
(U.S.) my.gmc.com
The GMC online owner experience
is a one-stop resource that allows
interaction with GMC and keeps
important vehicle-specific
information in one place.Membership Benefits
E:
Download owner ’s manuals
and view vehicle-specific how-to
videos.
G: View maintenance schedules,
alerts, and OnStar onboard vehicle
diagnostic information. Schedule
service appointments.
I: View and print dealer-recorded
service records and self-recorded
service records.
D: Select a dealer and view
locations, maps, phone numbers,
and hours.
r: Track your vehicle’s warranty
information.
J: View active recalls by Vehicle
Identification Number (VIN). See
Vehicle Identification Number (VIN)
0 460.
H:View GM Card, SiriusXM
Satellite radio (if equipped), and
OnStar account information (if
equipped).
F: Chat live with online help
representatives. See my.gmc.com to register your
vehicle.
GMC Centre (Canada) gmc.ca
Take a trip to the GMC Centre:
.
Chat live with online help
representatives.
. Use the Vehicle Tools section.
. Access third party enthusiast
sites and social media networks.
. Locate resources such as
lease-end, financing, and
warranty information.
. Retrieve your favorite articles,
quizzes, tips, and multimedia
galleries organized into the
Features and Auto Care
Sections.
. Download the owner ’s manual
for your vehicle, quickly and
easily.
. Find the GMC-recommended
maintenance services for your
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Customer Information 469
GM Mobility
Reimbursement Program
This program is available to
qualified applicants for cost
reimbursement, up to certain limits,
of eligible aftermarket adaptive
equipment required for the vehicle,
such as hand controls or a
wheelchair/scooter lift for the
vehicle.
To learn about the GM Mobility
program, see www.gmmobility.com
or call the GM Mobility Assistance
Center at 1-800-323-9935. Text
Telephone (TTY) users, call
1-800-833-9935.
General Motors of Canada also has
a Mobility program. See www.gm.ca
or call 1-800-GM-DRIVE
(800-463-7483) for details. TTY
users call 1-800-263-3830.
Roadside Assistance
Program
For U.S.-purchased vehicles, call
1-888-881-3302; (Text Telephone
(TTY): 1-888-889-2438).
For Canadian-purchased vehicles,
call 1-800-268-6800.
Service is available 24 hours a day,
365 days a year.
Calling for Assistance
When calling Roadside Assistance,
have the following information
ready:
.Your name, home address, and
home telephone number
. Telephone number of your
location
. Location of the vehicle
. Model, year, color, and license
plate number of the vehicle
. Odometer reading, Vehicle
Identification Number (VIN), and
delivery date of the vehicle
. Description of the problem
Coverage
Services are provided for the
duration of the vehicle's powertrain
warranty.
In the U.S., anyone driving the
vehicle is covered. In Canada, a
person driving the vehicle without
permission from the owner is not
covered.
Roadside Assistance is not a part of
the New Vehicle Limited Warranty.
General Motors North America and
GMC reserve the right to make any
changes or discontinue the
Roadside Assistance program at
any time without notification.
General Motors North America and
GMC reserve the right to limit
services or payment to an owner or
driver if they decide the claims are
made too often, or the same type of
claim is made many times.
Services Provided
.Emergency Fuel Delivery:
Delivery of enough fuel for the
vehicle to get to the nearest
service station.

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Customer Information 473
Aftermarket collision parts are also
available. These are made by
companies other than GM and may
not have been tested for the vehicle.
As a result, these parts may fit
poorly, exhibit premature durability/
corrosion problems, and may not
perform properly in subsequent
collisions. Aftermarket parts are not
covered by the GM New Vehicle
Limited Warranty, and any vehicle
failure related to such parts is not
covered by that warranty.
Repair Facility
GM also recommends that you
choose a collision repair facility that
meets your needs before you ever
need collision repairs. Your dealer
may have a collision repair center
with GM-trained technicians and
state-of-the-art equipment, or be
able to recommend a collision repair
center that has GM-trained
technicians and comparable
equipment.
Insuring the Vehicle
Protect your investment in the GM
vehicle with comprehensive and
collision insurance coverage. There
are significant differences in the
quality of coverage afforded by
various insurance policy terms.
Many insurance policies provide
reduced protection to the GM
vehicle by limiting compensation for
damage repairs through the use of
aftermarket collision parts. Some
insurance companies will not
specify aftermarket collision parts.
When purchasing insurance, we
recommend that you ensure that the
vehicle will be repaired with GM
original equipment collision parts.
If such insurance coverage is not
available from your current
insurance carrier, consider switching
to another insurance carrier.
If the vehicle is leased, the leasing
company may require you to have
insurance that ensures repairs with
Genuine GM Original Equipment
Manufacturer (OEM) parts or
Genuine Manufacturer replacementparts. Read the lease carefully, as
you may be charged at the end of
the lease for poor quality repairs.
If a Crash Occurs
If there has been an injury, call
emergency services for help. Do not
leave the scene of a crash until all
matters have been taken care of.
Move the vehicle only if its position
puts you in danger, or you are
instructed to move it by a police
officer.
Give only the necessary information
to police and other parties involved
in the crash.
For emergency towing see
Roadside Assistance Program
0
469.
Gather the following information:
. Driver name, address, and
telephone number
. Driver license number
. Owner name, address, and
telephone number
. Vehicle license plate number