
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 ManualM
In 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 (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Introduction v
j:LATCH System Child
Restraints
*: Malfunction Indicator Lamp
::Oil Pressure
g:Outside Power Foldaway
Mirrors
O: Power
/:Remote Vehicle Start
>:Safety Belt Reminders
7:Tire Pressure Monitor
_: Tow/Haul Mode
d:Traction Control/StabiliTrak®
M:Windshield Washer Fluid

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 (9,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-9
PressIto heat the driver or
passenger seatback only.
Press
Jto heat the driver or
passenger seat cushion and
seatback.
Press
Ato cool the driver or
passenger seat.
See Heated and Cooled Front Seats
on page 3-7.
Head Restraint
Adjustment
Do not drive until the head restraints
for all occupants are installed and
adjusted properly.
To achieve a comfortable seating
position, change the seatback
recline angle as little as necessary
while keeping the seat and the head
restraint height in the proper
position.
See Head Restraints on page 3-2
and Power Seat Adjustment on
page 3-3.
Safety Belts
Refer to the following sections for
important information on how to use
safety belts properly.
.Safety Belts on page 3-10.
.How to Wear Safety Belts
Properly on page 3-11.
.Lap-Shoulder Belt on page 3-12.
.Lower Anchors and Tethers for
Children (LATCH System) on
page 3-38.
Passenger Sensing
System
United States
Canada and Mexico
The passenger sensing system (if
equipped) turns off the front
outboard passenger frontal airbag
under certain conditions. No other
airbag is affected by the passenger
sensing system. See Passenger
Sensing System on page 3-24.

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-8 Keys, Doors, and Windows
The vehicle's ignition must be
turned on and then back off to use
remote start again.
Canceling a Remote Start
To cancel a remote start, do one of
the following:
.Press and hold/until the
parking lamps turn off.
.Turn on the hazard warning
flashers.
.Turn the ignition on and then off.
Door Locks
{Warning
Unlocked doors can be
dangerous.
.Passengers, especially
children, can easily open the
doors and fall out of a moving
vehicle. When a door is
locked, the handle will not
open it. The chance of being
(Continued)
Warning (Continued)
thrown out of the vehicle in a
crash is increased if the
doors are not locked. So, all
passengers should wear
safety belts properly and the
doors should be locked
whenever the vehicle is
driven.
.Young children who get into
unlocked vehicles may be
unable to get out. A child can
be overcome by extreme heat
and can suffer permanent
injuries or even death from
heat stroke. Always lock the
vehicle whenever leaving it.
.Outsiders can easily enter
through an unlocked door
when you slow down or stop
the vehicle. Locking the doors
can help prevent this from
happening. There are several ways to lock and
unlock the vehicle.
From outside, use the Remote
Keyless Entry (RKE) transmitter or
the key in the driver door.
From inside, use the power door
locks. See
Power Door Locks on
page 2-9.
From inside, pull the door handle
once to unlock the door. Pull the
handle again to open the door.
See Vehicle Alarm System on
page 2-11.

Black plate (10,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-10 Keys, Doors, and Windows
Crew/Double Cab PremiumShown, Others Similar
Press
{to activate the safety locks
on the rear doors. The indicator light
comes on when activated. The
vehicle must be on, in ACC/
ACCESSORY, or in Retained
Accessory Power (RAP). See
Retained Accessory Power (RAP)
on page 9-29.
If the indicator light flashes, the
feature may not be working properly.
Doors
Tailgate
{Warning
It is extremely dangerous to ride
on the tailgate, even when the
vehicle is operated at low speeds.
People riding on the tailgate can
easily lose their balance and fall
in response to vehicle
maneuvers. Falling from a moving
vehicle may result in serious
injuries or death. Do not allow
people to ride on the tailgate. Be
sure everyone in your vehicle is in
a seat and using a safety belt
properly.
On vehicles with a lock on the
tailgate, use the key to lock or
unlock the tailgate.
Open the tailgate by lifting up on its
handle while pulling the
tailgate down. To shut the tailgate, firmly push it
upward until it latches.
After closing the tailgate, pull it back
to be sure it latches securely.
Tailgate Removal
The tailgate can be removed to
allow for different loading situations.
Assistance may be needed with the
removal to avoid damage to the
vehicle.
On vehicles with a Rear Vision
Camera, it must be disconnected
before removing the tailgate. See
Driver Assistance Systems on
page 9-55.

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-1
Seats and
Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . 3-2
Front Seats
Power Seat Adjustment . . . . . . . 3-3
Lumbar Adjustment . . . . . . . . . . . 3-3
Reclining Seatbacks . . . . . . . . . . 3-4
Memory Seats . . . . . . . . . . . . . . . . 3-5
Heated and Cooled FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . 3-9
Safety Belts
Safety Belts . . . . . . . . . . . . . . . . . . 3-10
How to Wear Safety BeltsProperly . . . . . . . . . . . . . . . . . . . . 3-11
Lap-Shoulder Belt . . . . . . . . . . . 3-12 Safety Belt Use During
Pregnancy . . . . . . . . . . . . . . . . . . 3-15
Safety Belt Extender . . . . . . . . . 3-15
Safety System Check . . . . . . . . 3-16
Safety Belt Care . . . . . . . . . . . . . 3-16
Replacing Safety Belt System Parts after a Crash . . . . . . . . . 3-16
Airbag System
Airbag System . . . . . . . . . . . . . . . 3-17
Where Are the Airbags? . . . . . 3-18
When Should an AirbagInflate? . . . . . . . . . . . . . . . . . . . . . 3-20
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . 3-22
How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . 3-22
What Will You See after an Airbag Inflates? . . . . . . . . . . . . 3-22
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . 3-24
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . 3-28 Adding Equipment to the
Airbag-Equipped Vehicle . . . 3-28
Airbag System Check . . . . . . . . 3-29
Replacing Airbag System Parts after a Crash . . . . . . . . . 3-30
Child Restraints
Older Children . . . . . . . . . . . . . . . 3-30
Infants and Young
Children . . . . . . . . . . . . . . . . . . . . 3-32
Child Restraint Systems . . . . . 3-35
Where to Put the Restraint . . . 3-37
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . 3-38
Replacing LATCH System Parts After a Crash . . . . . . . . . 3-45
Securing Child Restraints (Rear Seat) . . . . . . . . . . . . . . . . . 3-45
Securing Child Restraints (Front Passenger Seat) . . . . 3-47

Black plate (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
3-4 Seats and Restraints
To adjust the power lumbar support:
.Press and hold the control
forward to increase or rearward
to decrease upper and lower
lumbar support at the same time.
.Press and hold the control up to
increase upper lumbar support
and decrease lower lumbar
support.
Press and hold the control down
to increase lower lumbar support
and decrease upper lumbar
support.
Reclining Seatbacks
To adjust the seatback:
.Tilt the top of the control
rearward to recline.
.Tilt the top of the control forward
to raise.
{Warning
Sitting in a reclined position when
the vehicle is in motion can be
dangerous. Even when buckled
up, the safety belts cannot do
their job.
The shoulder belt will not be
against your body. Instead, it will
be in front of you. In a crash, you
could go into it, receiving neck or
other injuries.
The lap belt could go up over
your abdomen. The belt forces
would be there, not at your pelvic
bones. This could cause serious
internal injuries.
For proper protection when the
vehicle is in motion, have the
seatback upright. Then sit well
back in the seat and wear the
safety belt properly.