
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 147passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on.
The front passenger seat belt
reminder light and chime may turn
on if an object is put on the seat
such as a briefcase, handbag,
grocery bag, laptop, or other
electronic device. To turn off the
reminder light and/or chime, remove
the object from the seat or buckle
the seat belt.
Airbag Readiness Light This light shows if there is an
electrical problem with the airbag
system. The system check includes
the airbag sensor(s), passenger
sensing system (if equipped), the
pretensioners, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
see Airbag System 0 77 . The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.
{ WarningIf the airbag readiness light stays
on after the vehicle is started or
comes on while driving, it means
the airbag system might not be
working properly. The airbags in
the vehicle might not inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
If there is a problem with the airbag
system, a Driver Information Center
(DIC) message may also come on. Airbag On-Off Light If the vehicle has an airbag on-off
switch, it also has a passenger
airbag status indicator located in the
overhead console.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
ON and OFF, or the symbol for on
and off, will light for several seconds
as a system check. Then, after
several more seconds, the status
indicator ON or OFF, or either the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
148 Instruments and Controls on or off symbol, will light to let you
know the status of the front
outboard passenger frontal airbag.
When the front outboard passenger
frontal airbag is manually turned off
using the airbag on-off switch on the
instrument panel endcap, the OFF
indicator light or the off symbol will
come on and stay on as a reminder
that the airbag has been turned off.
This light will go off when the airbag
has been turned on. See Airbag
On-Off Switch 0 84 for more
information, including important
safety information.
{ 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 identified by the national
government. See Airbag On-Off
Switch 0 84 for more information,
including important safety
information.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
(Continued) Warning (Continued) with the airbag system. For
example, the front outboard
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.
If the word ON or the on symbol is
lit, it means that the front outboard
passenger frontal airbag is enabled
(may inflate). See Airbag On-Off
Switch 0 84 for more information,
including important safety
information.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the airbag
on-off switch. See your dealer for
service.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 149
Passenger Airbag Status
Indicator If the vehicle has the passenger
sensing system, the overhead
console will have a passenger
airbag status indicator. See
Passenger Sensing System 0 86 for
important safety information.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
for on and off, for several seconds
as a system check. Then, after several more seconds, the status
indicator will light either ON or OFF,
or either the on or off symbol, to let
you know the status of the front
outboard passenger frontal airbag.
If the word ON or the on symbol is
lit on the passenger airbag status
indicator, it means that the front
outboard passenger frontal airbag is
allowed to inflate.
If the word OFF or the off symbol is
lit on the airbag status indicator, it
means that the passenger sensing
system has turned off the front
outboard passenger frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the
passenger sensing system. See
your dealer for service.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
(Continued) Warning (Continued) with the airbag system. 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.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
It should go out when the engine is
started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 257This position locks the ignition and
steering wheel. It also locks the
transmission. The key can be
removed in LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.
Do not turn the engine off when the
vehicle is moving. This may cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. After shifting to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location.
3. Come to a complete stop. Shift
to P (Park). Turn the ignition to
LOCK/OFF.
4. Set the parking brake. See
Parking Brake 0 281 .
The shift lever must be in P (Park)
to turn the ignition switch to
LOCK/OFF.
{ WarningTurning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
turn the ignition to ACC/
ACCESSORY. CautionUsing a tool to force the key to
turn in the ignition could cause
damage to the switch or break the
key. Use the correct key, make
sure it is all the way in, and turn it
only with your hand. If the key
cannot be turned by hand, see
your dealer.
1 (ACC/ACCESSORY) : This
position lets things like the radio
and the windshield wipers operate
while the engine is off. It also
unlocks the steering wheel. Use this
position if the vehicle must be
pushed or towed.
2 (ON/RUN) : This position can be
used to operate the electrical
accessories and to display some
instrument cluster warning and
indicator lights. This position can
also be used for service and
diagnostics, and to verify the proper
operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
386 Vehicle Care Fuses Usage
2 Accessory power
outlet 4
7 Body control module 4
8 Body control module 8
9 Rear seat
entertainment
10 Cargo lamp
15 Steering wheel
controls
18 Radio
19 –
20 Sunroof
23 Airbag/Info
26 Export/Power take off/
Special equipment
option/Battery 1
27 Obstacle detection/
USB ports
28 Body control module 2
32 Special equipment
option/Battery 2 Fuses Usage
35 Air conditioning
inverter
36 Amplifier
37 Battery system
39 Rear sliding window
42 Right door window
motor
43 Front blower
44 Special equipment
option
45 Body control module 6
46 Body control module 7
47 Passenger seat
Relays Usage
50 Retained accessory
power
51 Rear sliding
window open
52 Rear sliding window
close Instrument Panel Fuse
Block (Left)
The left instrument panel fuse block
access door is on the driver side
edge of the instrument panel.
Pull off the cover to access the fuse
block.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 491
Index A Accessories and
Modifications . . . . . . . . . . . . . . . . . . 343
Accessory Power . . . . . . . . . . . . . . . 260
Active Fuel Management . . . . . . . 264
Add-On Electrical Equipment . . . 336
Adding a Snow Plow or
Similar Equipment . . . . . . . . . . . . . 337
Additional Information
OnStar . . . . . . . . . . . . . . . . . . . . . . . 485
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . . . 453
Adjustable Throttle and
Brake Pedal . . . . . . . . . . . . . . . . . . . 256
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 60
Agreements
Trademarks and License . . . . . 218
Air Cleaner/Filter, Engine . . . . . . . 358
Air Conditioning . . . . . .224, 226, 228
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . 232
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 231
Airbag System
Check . . . . . . . . . . . . . . . . . . . . . . . . . . 91
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 82
Passenger Sensing System . . . . 86 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 82
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 82
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 80
Where Are the Airbags? . . . . . . . . 78
Airbags
Adding Equipment to the
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . 90
Light On-Off . . . . . . . . . . . . . . . . . . 147
On-Off Light . . . . . . . . . . . . . . . . . . 147
On-Off Switch . . . . . . . . . . . . . . . . . . 84
Passenger Status Indicator . . . 149
Readiness Light . . . . . . . . . . . . . . 147
Servicing Airbag-Equipped
Vehicles . . . . . . . . . . . . . . . . . . . . . . . 90
System Check . . . . . . . . . . . . . . . . . . 77
Alarm
Vehicle Security . . . . . . . . . . . . . . . . 44
All-Season Tires . . . . . . . . . . . . . . . . 389
All-Terrain Tires . . . . . . . . . . . . . . . . . 391
AM-FM Radio . . . . . . . . . . . . . . . . . . . 190
Antenna
Fixed Mast . . . . . . . . . . . . . . . . . . . 194
Multi-band . . . . . . . . . . . . . . . . . . . . 194
Antilock Brake System (ABS) . . . 280

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 497Lamps (cont'd)
Exterior Controls . . . . . . . . . . . . . . 176
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . 178
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Malfunction Indicator
(Check Engine) . . . . . . . . . . . . . 150
On Reminder . . . . . . . . . . . . . . . . . 157
Reading . . . . . . . . . . . . . . . . . . . . . . 183
Lane Departure
Warning (LDW) . . . . . . . . . . . . . . . . 295
Lane Departure Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Lane Keep Assist (LKA) . . . . . . . . 297
Lane Keep Assist Light . . . . . . . . . 154
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 75
Lap-Shoulder Belt . . . . . . . . . . . . . . . 71
LATCH System
Replacing Parts after a
Crash . . . . . . . . . . . . . . . . . . . . . . . . 111
LATCH, Lower Anchors and
Tethers for Children . . . . . . . . . . . . 99
LED Lighting . . . . . . . . . . . . . . . . . . . . 378
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . 184
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Illumination Control . . . . . . . . . . . 182 Lighting (cont'd)
LED . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Lights
Airbag On-Off . . . . . . . . . . . . . . . . . 147
Airbag Readiness . . . . . . . . . . . . . 147
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 152
Brake System Warning . . . . . . . 152
Charging System . . . . . . . . . . . . . 149
Check Engine (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Cruise Control . . . . . . . . . . . . . . . . 158
Door Ajar . . . . . . . . . . . . . . . . . . . . . 158
Engine Coolant
Temperature Warning . . . . . . . 155
Engine Oil Pressure . . . . . . . . . . 156
Flash-to-Pass . . . . . . . . . . . . . . . . . 179
Four-Wheel-Drive . . . . . . . . . . . . . 153
Front Fog Lamp . . . . . . . . . . . . . . 157
High-Beam On . . . . . . . . . . . . . . . . 157
High/Low Beam Changer . . . . . 179
Hill Descent Control . . . . . . . . . . 153
Lane Departure Warning . . . . . . 153
Lane Keep Assist . . . . . . . . . . . . . 154
Low Fuel Warning . . . . . . . . . . . . 156
Seat Belt Reminders . . . . . . . . . . 146
Security . . . . . . . . . . . . . . . . . . . . . . 157
StabiliTrak OFF . . . . . . . . . . . . . . . 154 Lights (cont'd)
Tire Pressure . . . . . . . . . . . . . . . . . 156
Tow/Haul Mode . . . . . . . . . . . . . . . 153
Traction Control System
(TCS)/StabiliTrak . . . . . . . . . . . . 155
Traction Off . . . . . . . . . . . . . . . . . . . 154
Locking Rear Axle . . . . . . . . . . . . . . 285
Locks
Automatic Door . . . . . . . . . . . . . . . . . 41
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Lockout Protection . . . . . . . . . . . . . . 42
Power Door . . . . . . . . . . . . . . . . . . . . . 41
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Loss of Control . . . . . . . . . . . . . . . . . 238
Low Fuel Warning Light . . . . . . . . . 156
Low-Profile Tires . . . . . . . . . . . . . . . . 390
Lower Anchors and Tethers
for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . . . 99
Lumbar Adjustment . . . . . . . . . . . . . . 60
Front Seats . . . . . . . . . . . . . . . . . . . . . 60
M Maintenance
Records . . . . . . . . . . . . . . . . . . . . . . 459
Maintenance and Care
Additional . . . . . . . . . . . . . . . . . . . . . 453
Maintenance Schedule . . . . . . . . . 448

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 501StabiliTrak
OFF Light . . . . . . . . . . . . . . . . . . . . . 154
Start Assist, Hill . . . . . . . . . . . . . . . . . 282
Start Vehicle, Remote . . . . . . . . . . . 39
Starter Switch Check . . . . . . . . . . . 374
Starting the Engine . . . . . . . . . . . . . 258
Steering . . . . . . . . . . . . . . . . . . . . . . . . 237
Fluid, Power . . . . . . . . . . . . . . . . . . 365
Heated Wheel . . . . . . . . . . . . . . . . 130
Wheel Adjustment . . . . . . . . . . . . 129
Wheel Controls . . . . . . . . . . . . . . . 129
Steps
Power Assist . . . . . . . . . . . . . . . . . . . 43
Stoplamps and Back-up Lamps
Bulb Replacement . . . . . . . . . . . . 378
Storage Areas
Center Console . . . . . . . . . . . . . . . 125
Floor Console . . . . . . . . . . . . . . . . 126
Glove Box . . . . . . . . . . . . . . . . . . . . 124
Instrument Panel . . . . . . . . . . . . . 124
Sunglasses . . . . . . . . . . . . . . . . . . . 125
Storage Compartments . . . . . . . . . 124
Struts
Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
Stuck Vehicle . . . . . . . . . . . . . . . . . . . 247
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . 55
Sunglass Storage . . . . . . . . . . . . . . . 125
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Switches
Airbag On-Off . . . . . . . . . . . . . . . . . . . 84
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System
Forward Collision
Alert (FCA) . . . . . . . . . . . . . . . . . . 292
Infotainment . . . . . . . . . . . . . 186, 478
Noise Control . . . . . . . . . . . . . . . . . 373
Systems
Driver Assistance . . . . . . . . . . . . . 288
T Tachometer . . . . . . . . . . . . . . . . . . . . . 142
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Taillamps
Bulb Replacement . . . . . . . . . . . . 378
Text Telephone (TTY) Users . . . . 468
Theft-Deterrent Systems . . . . . . . . . 46
Immobilizer . . . . . . . . . . . . . . . . . . . . . 46
Throttle, Adjustable . . . . . . . . . . . . . 256
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season . . . . . . . . . . . . . . . . . . . . 389
All-Terrain . . . . . . . . . . . . . . . . . . . . 391
Buying New Tires . . . . . . . . . . . . . 408
Chains . . . . . . . . . . . . . . . . . . . . . . . . 413
Changing . . . . . . . . . . . . . . . . . . . . . 415
Designations . . . . . . . . . . . . . . . . . 393 Tires (cont'd)
Different Size . . . . . . . . . . . . . . . . . 409
Full-Size Spare . . . . . . . . . . . . . . . 425
If a Tire Goes Flat . . . . . . . . . . . . 413
Inspection . . . . . . . . . . . . . . . . . . . . 404
Low Profile . . . . . . . . . . . . . . . . . . . 390
Pressure . . . . . . . . . . . . . . . . . 397, 399
Pressure Light . . . . . . . . . . . . . . . . 156
Pressure Monitor Operation . . 400
Pressure Monitor System . . . . . 399
Rotation . . . . . . . . . . . . . . . . . . . . . . 405
Sidewall Labeling . . . . . . . . . . . . . 391
Terminology and Definitions . . 395
Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . . . 410
Wheel Alignment and Tire
Balance . . . . . . . . . . . . . . . . . . . . . .411
Wheel Replacement . . . . . . . . . . 412
When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 407
Winter . . . . . . . . . . . . . . . . . . . . . . . . 390
Tow/Haul Mode . . . . . . . . . . . . . . . . . 271
Tow/Haul Mode Light . . . . . . . . . . . 153
Towing
Driving Characteristics . . . . . . . . 303
Equipment . . . . . . . . . . . . . . . . . . . . 325
General Information . . . . . . . . . . 303
Recreational Vehicle . . . . . . . . . . 430