
Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
2015 GMC Sierra Denali Owner Manual MIn Brief . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Instrument Panel . . . . . . . . . . . . . . 1-2
Initial Drive Information . . . . . . . . 1-4
Vehicle Features . . . . . . . . . . . . . 1-16
Performance and
Maintenance . . . . . . . . . . . . . . . . 1-20
Keys, Doors, and
Windows . . . . . . . . . . . . . . . . . . . . 2-1
Keys and Locks . . . . . . . . . . . . . . . 2-1
Doors . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Vehicle Security . . . . . . . . . . . . . . 2-11
Exterior Mirrors . . . . . . . . . . . . . . . 2-14
Interior Mirrors . . . . . . . . . . . . . . . . 2-19
Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Roof . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Seats and Restraints . . . . . . . . . 3-1
Head Restraints . . . . . . . . . . . . . . . 3-2
Front Seats . . . . . . . . . . . . . . . . . . . . 3-3
Rear Seats . . . . . . . . . . . . . . . . . . . . 3-9
Safety Belts . . . . . . . . . . . . . . . . . . 3-10
Airbag System . . . . . . . . . . . . . . . . 3-17
Child Restraints . . . . . . . . . . . . . . 3-30 Storage . . . . . . . . . . . . . . . . . . . . . . . 4-1
Storage Compartments . . . . . . . . 4-1
Additional Storage Features . . . 4-3
Instruments and Controls . . . . 5-1
Controls . . . . . . . . . . . . . . . . . . . . . . . 5-2
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . 5-8
Information Displays . . . . . . . . . . 5-27
Vehicle Messages . . . . . . . . . . . . 5-31
Vehicle Personalization . . . . . . . 5-42
Universal Remote System . . . . 5-49
Lighting . . . . . . . . . . . . . . . . . . . . . . . 6-1
Exterior Lighting . . . . . . . . . . . . . . . 6-1
Interior Lighting . . . . . . . . . . . . . . . . 6-6
Lighting Features . . . . . . . . . . . . . . 6-8
Infotainment System . . . . . . . . . 7-1
Introduction . . . . . . . . . . . . . . . . . . . . 7-1 Climate Controls . . . . . . . . . . . . . 8-1
Climate Control Systems . . . . . . 8-1
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 8-4
Maintenance . . . . . . . . . . . . . . . . . . . 8-5
Driving and Operating . . . . . . . . 9-1
Driving Information . . . . . . . . . . . . . 9-2
Starting and Operating . . . . . . . 9-23
Engine Exhaust . . . . . . . . . . . . . . 9-32
Automatic Transmission . . . . . . 9-33
Drive Systems . . . . . . . . . . . . . . . . 9-40
Brakes . . . . . . . . . . . . . . . . . . . . . . . 9-46
Ride Control Systems . . . . . . . . 9-49
Cruise Control . . . . . . . . . . . . . . . . 9-52
Driver Assistance Systems . . . 9-55
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Trailer Towing . . . . . . . . . . . . . . . . 9-68
Conversions and Add-Ons . . . 9-88
Vehicle Care . . . . . . . . . . . . . . . . . 10-1
General Information . . . . . . . . . . 10-2
Vehicle Checks . . . . . . . . . . . . . . . 10-3
Headlamp Aiming . . . . . . . . . . . 10-36
Bulb Replacement . . . . . . . . . . 10-36
Electrical System . . . . . . . . . . . . 10-40
Wheels and Tires . . . . . . . . . . . 10-50

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-1
In Brief Instrument Panel Instrument Panel . . . . . . . . . . . . . . 1-2
Initial Drive Information Remote Keyless Entry (RKE)
System . . . . . . . . . . . . . . . . . . . . . . 1-4
Remote Vehicle Start . . . . . . . . . 1-5
Door Locks . . . . . . . . . . . . . . . . . . . 1-5
Windows . . . . . . . . . . . . . . . . . . . . . . 1-6
Seat Adjustment . . . . . . . . . . . . . . 1-7
Memory Features . . . . . . . . . . . . . 1-8
Heated and Cooled Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Head Restraint Adjustment . . . . 1-9
Safety Belts . . . . . . . . . . . . . . . . . . . 1-9
Passenger Sensing System . . . 1-9
Mirror Adjustment . . . . . . . . . . . . 1-10 Steering Wheel
Adjustment . . . . . . . . . . . . . . . . . 1-11
Throttle and Brake Pedal
Adjustment . . . . . . . . . . . . . . . . . 1-12
Interior Lighting . . . . . . . . . . . . . . 1-12
Exterior Lighting . . . . . . . . . . . . . 1-13
Windshield Wiper/Washer . . . . 1-13
Climate Controls . . . . . . . . . . . . . 1-14
Transmission . . . . . . . . . . . . . . . . 1-15
Four-Wheel Drive . . . . . . . . . . . . 1-15
Vehicle Features Infotainment System . . . . . . . . . 1-16
Steering Wheel Controls . . . . . 1-16
Cruise Control . . . . . . . . . . . . . . . 1-17
Driver Information
Center (DIC) . . . . . . . . . . . . . . . 1-17
Forward Collision Alert (FCA)
System . . . . . . . . . . . . . . . . . . . . . 1-18 Lane Departure
Warning (LDW) . . . . . . . . . . . . . 1-18
Rear Vision
Camera (RVC) . . . . . . . . . . . . . 1-18
Parking Assist . . . . . . . . . . . . . . . 1-18
Power Outlets . . . . . . . . . . . . . . . 1-18
Universal Remote System . . . 1-19
Sunroof . . . . . . . . . . . . . . . . . . . . . . 1-19
Performance and Maintenance Traction Control/Electronic
Stability Control . . . . . . . . . . . . 1-20
Tire Pressure Monitor . . . . . . . . 1-20
Engine Oil Life System . . . . . . 1-21
E85 or FlexFuel . . . . . . . . . . . . . . 1-21
Driving for Better Fuel
Economy . . . . . . . . . . . . . . . . . . . 1-21
Roadside Assistance
Program . . . . . . . . . . . . . . . . . . . . 1-22
OnStar ®
. . . . . . . . . . . . . . . . . . . . . 1-22

Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-13
Press
m or
n next to each reading
lamp to turn it on or off.
For more information about interior
lighting, see Instrument Panel
Illumination Control on page 6-6 .
Exterior Lighting The exterior lamp control is on the
instrument panel to the left of the
steering wheel.
O : Turns off the automatic
headlamps and Daytime Running
Lamps (DRL). Turn the headlamp
control to the off position again to
turn the automatic headlamps or
DRL back on.
For vehicles first sold in Canada, off
will only work when the vehicle is in
P (Park).
AUTO: Automatically turns on the
headlamps, parking lamps,
taillamps, instrument panel lights,
roof marker lamps (if equipped),
front/rear sidemarker lamps, and
license plate lamps.
; : Turns on the parking lamps
including all lamps, except the
headlamps.
5 : Turns on the headlamps
together with the parking lamps and
instrument panel lights. See: .
Exterior Lamp Controls on
page 6-1 . .
Daytime Running Lamps (DRL)
on page 6-3 . .
Fog Lamps on page 6-5 .
Windshield Wiper/Washer
The windshield wiper control is on
the turn signal lever.
The windshield wipers are controlled
by turning the band with
z on it.
1 : Fast wipes.
w : Slow wipes.
3 INT: Turn the band up for more
frequent wipes or down for less
frequent wipes.

Black plate (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-19Vehicles with Bench Seats .
One on the center stack below
the climate control system. .
One or two in the storage area
on the bench seat.
Lift the cover to access and replace
when not in use.
See Power Outlets on page 5-5 .
Universal Remote System
If equipped with the Universal
Remote system, these buttons will
be in the front overhead console.
This system provides a way to
replace up to three remote control
transmitters used to activate
devices such as garage door
openers, security systems, and
home automation devices. See Universal Remote System on
page 5-49 .
Sunroof
If equipped, the sunroof only
operates when the ignition is in
ACC/ACCESSORY or ON/RUN,
or when Retained Accessory Power
(RAP) is active. See Retained
Accessory Power (RAP) on
page 9-29 . Vent: From the closed position,
press the rear of the TILT switch to
vent the sunroof.
Manual-Open/Manual-Close: To
open the sunroof, press and hold
the rear of the SLIDE switch until
the sunroof reaches the desired
position. Press and hold the front of
the SLIDE switch to close it.
Express-Open/Express-Close: To
express-open the sunroof, fully
press and release the rear of the
SLIDE switch until the sunroof
reaches the desired position. To
express-close the sunroof, fully
press and release the front of the
SLIDE switch. Press the switch
again to stop it.
When the sunroof is opened, an air
deflector will automatically raise.
The air deflector will retract when
the sunroof is closed.

Black plate (20,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
1-20 In Brief The sunroof also has a sunshade
that can be pulled forward to block
the rays of the sun. Open and close
the sunshade manually.
If an object is in the path of the
sunroof while it is closing, the
anti-pinch feature will detect the
object and stop the sunroof.
See Sunroof on page 2-22 .
Performance and
Maintenance Traction Control/
Electronic Stability
Control The vehicle has a traction control
system that limits wheel spin and
the StabiliTrak system that assists
with directional control of the vehicle
in difficult driving conditions. Both
systems come on automatically
when the vehicle is started and
begins to move. .
To turn off traction control, press
and release
g on the center
stack. The traction off light
idisplays in the instrument
cluster. The appropriate Driver
Information Center (DIC)
message displays. See Ride
Control System Messages on
page 5-36 . .
To turn off both traction control
and StabiliTrak, press and
hold
g until
i and
g illuminate
in the instrument cluster and the
appropriate DIC message
displays. See Ride Control
System Messages on page 5-36 . .
Press and release
g again to
turn on both systems. .
StabiliTrak will automatically turn
on if the vehicle exceeds
56 km/h (35 mph). Traction
control will remain off.
See Traction Control/Electronic
Stability Control on page 9-49 .
Tire Pressure Monitor This vehicle may have a Tire
Pressure Monitor System (TPMS).

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-1
Keys, Doors, and
Windows Keys and Locks Keys . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Remote Keyless Entry (RKE)
System . . . . . . . . . . . . . . . . . . . . . . 2-4
Remote Keyless Entry (RKE)
System Operation . . . . . . . . . . . 2-4
Remote Vehicle Start . . . . . . . . . 2-7
Door Locks . . . . . . . . . . . . . . . . . . . 2-8
Power Door Locks . . . . . . . . . . . . 2-9
Delayed Locking . . . . . . . . . . . . . . 2-9
Automatic Door Locks . . . . . . . . . 2-9
Lockout Protection . . . . . . . . . . . . 2-9
Safety Locks . . . . . . . . . . . . . . . . . . 2-9
Doors Tailgate . . . . . . . . . . . . . . . . . . . . . . 2-10
Vehicle Security Vehicle Security . . . . . . . . . . . . . . 2-11
Vehicle Alarm System . . . . . . . . 2-11
Immobilizer . . . . . . . . . . . . . . . . . . 2-12
Immobilizer Operation . . . . . . . 2-13 Exterior Mirrors Convex Mirrors . . . . . . . . . . . . . . 2-14
Trailer-Tow Mirrors . . . . . . . . . . . 2-14
Power Mirrors . . . . . . . . . . . . . . . . 2-14
Folding Mirrors . . . . . . . . . . . . . . . 2-16
Heated Mirrors . . . . . . . . . . . . . . . 2-17
Automatic Dimming Mirror . . . 2-17
Blind Spot Mirrors . . . . . . . . . . . 2-17
Reverse Tilt Mirrors . . . . . . . . . . 2-18
Interior Mirrors Interior Rearview Mirrors . . . . . 2-19
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . 2-19
Windows Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Power Windows . . . . . . . . . . . . . 2-19
Rear Windows . . . . . . . . . . . . . . . 2-22
Sun Visors . . . . . . . . . . . . . . . . . . . 2-22
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . 2-22 Keys and Locks Keys
{ WarningLeaving children in a vehicle with
the ignition key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the keys in the
ignition, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with the
ignition key.

Black plate (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-19
Interior Mirrors Interior Rearview Mirrors Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
If equipped with OnStar, the vehicle
may have three control buttons at
the bottom of the mirror. See your
dealer for more information about
OnStar and how to subscribe to it.
See OnStar Overview on page 14-1 .
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.
Automatic Dimming
Rearview Mirror The mirror will automatically reduce
the glare of the headlamps from
behind. The dimming feature comes
on each time the vehicle is started. Windows
{ WarningNever leave a child, a helpless
adult, or a pet alone in a vehicle,
especially with the windows
closed in warm or hot weather.
They can be overcome by the
extreme heat and suffer
permanent injuries or even death
from heat stroke. The vehicle aerodynamics are
designed to improve fuel economy
performance. This may result in a
pulsing sound when either rear
window is down and the front
windows are up. To reduce the
sound, open either a front window
or the sunroof, if equipped.
Power Windows
{ WarningChildren could be seriously
injured or killed if caught in the
path of a closing window. Never
leave keys in a vehicle with
children. When there are children
in the rear seat, use the window
lockout button to prevent
operation of the windows. See
Keys on page 2-1 .

Black plate (22,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-22 Keys, Doors, and Windows
Rear Windows Power Sliding Rear Window
If equipped, the power sliding rear
window works when the ignition has
been turned to ACC/ACCESSORY
or ON/RUN, or when Retained
Accessory Power (RAP) is active.
See Retained Accessory Power
(RAP) on page 9-29 ..
Press the switch to open the
window. .
Pull the switch to close the
window. The power sliding rear window
cannot be operated manually.
Sun Visors
Pull the sun visor down to block
glare. Detach the sun visor from the
center mount to pivot to the side
window or, if equipped, extend
along the rod. Roof Sunroof
If equipped, the sunroof operates
when the ignition is in ACC/
ACCESSORY or ON/RUN, or when
Retained Accessory Power (RAP) is
active. See Retained Accessory
Power (RAP) on page 9-29 .
Vent: From the closed position,
press the rear of the TILT switch to
vent the sunroof.