service GMC SIERRA DENALI 2018 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Contents Introduction . . . . . . . . . . . . . . . . . . . . . . 2
In Brief . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Keys, Doors, and Windows . . . . . 34
Seats and Restraints . . . . . . . . . . . 57
Storage . . . . . . . . . . . . . . . . . . . . . . . 124
Instruments and Controls . . . . . . 128
Lighting . . . . . . . . . . . . . . . . . . . . . . . 176
Infotainment System . . . . . . . . . . 186
Climate Controls . . . . . . . . . . . . . . 224
Driving and Operating . . . . . . . . . 234
Vehicle Care . . . . . . . . . . . . . . . . . . 341
Service and Maintenance . . . . . 446
Technical Data . . . . . . . . . . . . . . . . 460
Customer Information . . . . . . . . . 465
Reporting Safety Defects . . . . . . 476
OnStar . . . . . . . . . . . . . . . . . . . . . . . . 479
Index . . . . . . . . . . . . . . . . . . . . 491

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
2 Introduction
Introduction The names, logos, emblems,
slogans, vehicle model names, and
vehicle body designs appearing in
this manual including, but not limited
to, GM, the GM logo, GMC, the
GMC Truck Emblem, SIERRA, and
DENALI are trademarks and/or
service marks of General Motors
LLC, its subsidiaries, affiliates,
or licensors.
For vehicles first sold in Canada,
substitute the name “ General
Motors of Canada Company ” for
GMC Division wherever it appears
in this manual. This manual describes features that
may or may not be on the vehicle
because of optional equipment that
was not purchased on the vehicle,
model variants, country
specifications, features/applications
that may not be available in your
region, or changes subsequent to
the printing of this owner ’ s manual.
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement for additional and
specific information on this engine.
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
Refer to the purchase
documentation relating to your
specific vehicle to confirm the
features.
Keep this manual in the vehicle for
quick reference. Canadian Vehicle Owners A French language manual can be
obtained from your dealer, at
www.helminc.com, or from:
Propriétaires Canadiens On peut obtenir un exemplaire de
ce guide en français auprès du
concessionnaire ou à l'adresse
suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Using this Manual To quickly locate information about
the vehicle, use the Index in the
back of the manual. It is an
alphabetical list of what is in the
manual and the page number where
it can be found.
Litho in U.S.A.
Part No. 84016542 B Second Printing ©
2017 General Motors LLC. All Rights Reserved.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Introduction 3
Danger, Warning, and
Caution Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{ DangerDanger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{ WarningWarning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage. A circle with a slash through it is a
safety symbol which means “ Do
Not, ” “ Do not do this, ” or “ Do not let
this happen. ”
Symbols The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M : Shown when the owner ’ s
manual has additional instructions
or information.
* : Shown when the service
manual has additional instructions
or information.
0 : Shown when there is more
information on another page —
“ see page. ” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
9 : Airbag Readiness Light
# : Air Conditioning
! : Antilock Brake System (ABS)
$ : Brake System Warning Light
" : Charging System
I : Cruise Control
` : Do Not Puncture
^ : Do Not Service
B : Engine Coolant Temperature
O : Exterior Lamps
_ : Flame/Fire Prohibited
. : Fuel Gauge
+ : Fuses
3 : Headlamp High/Low-Beam
Changer
j : ISOFIX/LATCH System Child
Restraints

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
In Brief 25MENU : Press to select a menu.
g : Press to seek the previous
station or track.
l : Press to seek the next station
or track.
See “ Base Radio ” in Overview
0 188 .
Base Radio with Touchscreen
O : Press to turn the system on.
Press and hold to turn it off. When
on, press to mute; press again to
unmute. Turn to increase or
decrease the volume.
{ : Press to go to the Home Page.
7 : Press to seek the previous
station or track.
6 : Press to seek the next station
or track.
See “ Base Radio with Touchscreen ”
in Overview 0 188 .
Setting the Clock
See Clock 0 132 . Satellite Radio Vehicles with a SiriusXM satellite
radio tuner and a valid SiriusXM
satellite radio subscription can
receive SiriusXM programming.
SiriusXM Satellite Radio
Service SiriusXM is a satellite radio service
based in the 48 contiguous United
States and 10 Canadian provinces.
SiriusXM satellite radio has a wide
variety of programming and
commercial-free music, coast to
coast, and in digital-quality sound.
A fee is required to receive the
SiriusXM service.
For more information refer to:
.
www.siriusxm.com or call
1-888-601-6296 (U.S.).
.
www.siriusxm.ca or call
1-877-438-9677 (Canada).
See Satellite Radio 0 192 .Portable Audio Devices This vehicle may have a 3.5 mm
(1/8 in) auxiliary input jack and USB
ports in the center stack, center
console, or under armrest. There
may be a USB port in the upper
glove box. External devices such as
iPods, laptop computers, MP3
players, and USB storage devices
may be connected, depending on
the audio system.
See USB Port 0 197 and Auxiliary
Jack 0 203 .
Bluetooth The Bluetooth system allows users
with a Bluetooth-enabled cell phone
to make and receive hands-free
calls using the vehicle audio system
and controls.
The Bluetooth-enabled cell phone
must be paired with the in-vehicle
Bluetooth system before it can be
used in the vehicle. Not all phones
will support all functions.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 37learned and all previously
known keys will no longer work
with the vehicle.
6. To learn a second key, turn the
ignition off, insert the second
key to be learned, and turn the
ignition on.
After two keys are learned, the
remaining keys can be learned by
following the procedure in
“ Programming with Two
Recognized Keys. ”
The key has a bar-coded key tag
that the dealer or qualified locksmith
can use to make new keys. Store
this information in a safe place, not
in the vehicle.
See your dealer if a replacement
key or additional key is needed.
If it becomes difficult to turn a key,
inspect the key blade for debris.
Periodically clean with a brush
or pick.
With an active OnStar service plan,
an OnStar Advisor may remotely
unlock the vehicle. See OnStar
Overview 0 479 . Remote Keyless Entry
(RKE) System See Radio Frequency Statement
0 475 .
If there is a decrease in the Remote
Keyless Entry (RKE) operating
range:
.
Check the distance. The
transmitter may be too far from
the vehicle.
.
Check the location. Other
vehicles or objects may be
blocking the signal.
.
Check the transmitter's battery.
See “ Battery Replacement ” later
in this section.
.
If the transmitter is still not
working correctly, see your
dealer or a qualified technician
for service.
Remote Keyless Entry
(RKE) System Operation The RKE transmitter functions may
work up to 60 m (197 ft) away from
the vehicle. Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 0 37 .
With Remote Start (without
Remote Start Similar)
/ : If equipped,
/ is used to start
the engine from outside the vehicle
using the RKE transmitter. See
Remote Vehicle Start 0 39 .
Q : Press to lock all doors and the
tailgate.
If enabled in vehicle personalization,
the turn signal lamps flash once to
indicate locking has occurred.
If enabled through vehicle

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 47When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers 0 381 .
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
0 34 . To program additional
transmitters, see your dealer.
Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system. Exterior Mirrors Convex Mirrors
{ WarningA convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
Manual Mirrors If equipped, adjust manual mirrors
by moving the mirror up and down
or left to right to see a little of the
side of the vehicle and to have a
clear view behind the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 65To stop Easy Exit Recall movement,
press any of the following memory
controls:
.
Power seat
.
Memory SET, 1, 2, or
B.
Power mirror, with the driver or
passenger side mirror selected
.
Power steering wheel,
if equipped
.
Adjustable pedals, if equipped
Obstructions
If something has blocked the driver
seat and/or power steering wheel
while recalling a memory position,
the recall may stop. Remove the
obstruction and try the recall again.
If the memory position still does not
recall, see your dealer for service. Heated and Ventilated
Front Seats
{ WarningIf temperature change or pain to
the skin cannot be felt, the seat
heater may cause burns. To
reduce the risk of burns, use care
when using the seat heater,
especially for long periods of
time. Do not place anything on
the seat that insulates against
heat, such as a blanket, cushion,
cover, or similar item. This may
cause the seat heater to
overheat. An overheated seat
heater may cause a burn or may
damage the seat. Heated and Ventilated Seat
Buttons Shown, Heated Seat
Buttons Similar
If equipped, the buttons are on the
center stack. To operate, the engine
must be running.
Press
I to heat the driver or
passenger seatback only.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 83
{ WarningWhen an airbag inflates, there
may be dust in the air. This dust
could cause breathing problems
for people with a history of
asthma or other breathing trouble.
To avoid this, everyone in the
vehicle should get out as soon as
it is safe to do so. If you have
breathing problems but cannot
get out of the vehicle after an
airbag inflates, then get fresh air
by opening a window or a door.
If you experience breathing
problems following an airbag
deployment, you should seek
medical attention.
The vehicle has a feature that may
automatically unlock the doors, turn
on the interior lamps and hazard
warning flashers, and shut off the
fuel system after the airbags inflate.
The feature may also activate,
without airbag inflation, after an
event that exceeds a predetermined
threshold. After turning the ignition off and then on again, the fuel
system will return to normal
operation; the doors can be locked,
the interior lamps can be turned off,
and the hazard warning flashers can
be turned off using the controls for
those features. If any of these
systems are damaged in the crash
they may not operate as normal.
{ WarningA crash severe enough to inflate
the airbags may have also
damaged important functions in
the vehicle, such as the fuel
system, brake and steering
systems, etc. Even if the vehicle
appears to be drivable after a
moderate crash, there may be
concealed damage that could
make it difficult to safely operate
the vehicle.
Use caution if you should attempt
to restart the engine after a crash
has occurred. In many crashes severe enough to
inflate the airbag, windshields are
broken by vehicle deformation.
Additional windshield breakage may
also occur from the front outboard
passenger airbag.
.
Airbags are designed to inflate
only once. After an airbag
inflates, you will need some new
parts for the airbag system.
If you do not get them, the
airbag system will not be there
to help protect you in another
crash. A new system will include
airbag modules and possibly
other parts. The service manual
for the vehicle covers the need
to replace other parts.
.
The vehicle has a crash sensing
and diagnostic module which
records information after a
crash. See Vehicle Data
Recording and Privacy 0 477
and Event Data Recorders
0 477 .
.
Let only qualified technicians
work on the airbag systems.
Improper service can mean that

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
84 Seats and Restraints an airbag system will not work
properly. See your dealer for
service.
Airbag On-Off Switch If the passenger side instrument
panel endcap has the switch
pictured in the following illustration,
the vehicle has an airbag on-off
switch that you can use to manually
turn on or off the front outboard
passenger frontal airbag. See
Instrument Panel 0 6 .
If the vehicle does not have an
airbag on-off switch, it may have a
passenger sensing system. See
Passenger Sensing System 0 86 . This switch should only be turned to
the off position if the person in the
front outboard passenger position is
a member of a passenger risk group
identified by the national
government as follows:
Infant. An infant (less than 1 year
old) must ride in the front seat
because:
.
My vehicle has no rear seat;
.
My vehicle has a rear seat too
small to accommodate a
rear-facing infant seat; or
.
The infant has a medical
condition which, according to the
infant's physician, makes it
necessary for the infant to ride in
the front seat so that the driver
can constantly monitor the
child's condition.
Child age 1 to 12. A child
age 1 to 12 must ride in the front
seat because:
.
My vehicle has no rear seat;
.
Although children ages 1 to 12
ride in the rear seat(s) whenever
possible, children ages 1 to 12 sometimes must ride in the front
because no space is available in
the rear seat(s) of my vehicle; or
.
The child has a medical
condition which, according to the
child's physician, makes it
necessary for the child to ride in
the front seat so that the driver
can constantly monitor the
child's condition.
Medical Condition. A passenger
has a medical condition which,
according to his or her physician:
.
Causes the passenger airbag to
pose a special risk for the
passenger; and
.
Makes the potential harm from
the passenger airbag in a crash
greater than the potential harm
from turning off the airbag and
allowing the passenger, even if
belted, to hit the instrument
panel or windshield in a crash.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 85
{ WarningIf the front outboard passenger
frontal airbag is turned off for a
person who is not in a risk group
identified by the national
government, that person will not
have the extra protection of an
airbag. In a crash, the airbag will
not be able to inflate and help
protect the person sitting there.
Do not turn off the front outboard
passenger frontal airbag unless
the person sitting there is in a risk
group. To turn off the front outboard
passenger frontal airbag, insert the
ignition key into the switch, push in,
and move the switch to the off
position.
The word OFF or the off symbol will
come on in the passenger airbag
status indicator located in the
overhead console to let you know
that the front outboard passenger
frontal airbag is off, after the system
check is completed. The airbag off
light will come on and stay on to let
you know that the front outboard
passenger frontal airbag is off. See
Airbag On-Off Light 0 147 . The front
outboard passenger airbag will
remain off until you turn it back on
again.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. For
example, the front outboard
(Continued) Warning (Continued) passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.
To turn the front outboard passenger
frontal airbag on again, insert the
ignition key into the switch, push in,
and move the switch to the on
position.