
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 (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 (9,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-9Press
I to heat the driver or
passenger seatback only.
Press
J to heat the driver or
passenger seat cushion and
seatback.
Press
A to 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 (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 Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Rear Seats Rear Seats . . . . . . . . . . . . . . . . . . . . 3-9
Safety Belts Safety Belts . . . . . . . . . . . . . . . . . . 3-10
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . 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 Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . 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 (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-3restraint and pull forward to the
desired locking position. To adjust
the head restraint rearward, grasp
the head restraint and pull forward
fully until the mechanism releases
and allows the head restraint to
return to the full rear position.
The front seat outboard head
restraints are not removable.
Rear Seats The rear seat has adjustable
headrests in the outboard seating
positions.
The height of the headrest can be
adjusted. Pull the headrest up to
raise it. To lower the headrest, push
the headrest down.
If you are installing a child restraint
in the rear seat, see “ Securing a
Child Restraint Designed for the
LATCH System ” under Lower
Anchors and Tethers for Children
(LATCH System) on page 3-38 .Front Seats Power Seat Adjustment
To adjust a power seat: .
Move the seat forward or
rearward by sliding the control
forward or rearward. .
Raise or lower the front part of
the seat cushion by moving the
front of the control up or down. .
Raise or lower the seat by
moving the rear of the control up
or down. To adjust the setback, see Reclining
Seatbacks on page 3-4 .
To adjust the lumbar support, see
Lumbar Adjustment on page 3-3 .
Some vehicles are equipped with a
feature that activates a vibrating
pulse alert in the driver seat to help
the driver avoid crashes. See Driver
Assistance Systems on page 9-55 .
Lumbar Adjustment

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-11safety belts. That is why wearing
safety belts makes such good
sense.
Questions and Answers About
Safety Belts Q: Will I be trapped in the vehicle
after a crash if I am wearing a
safety belt?
A: You could be — whether you are
wearing a safety belt or not.
Your chance of being conscious
during and after a crash, so you
can unbuckle and get out, is
much greater if you are belted.
Q: If my vehicle has airbags, why
should I have to wear safety
belts?
A: Airbags are supplemental
systems only; so they work with
safety belts — not instead of
them. Whether or not an airbag
is provided, all occupants still
have to buckle up to get the
most protection. Also, in nearly all states and in
all Canadian provinces, the law
requires wearing safety belts.
How to Wear Safety Belts
Properly This section is only for people of
adult size.
There are special things to know
about safety belts and children. And
there are different rules for smaller
children and infants. If a child will be
riding in the vehicle, see Older
Children on page 3-30 or Infants
and Young Children on page 3-32 .
Follow those rules for everyone's
protection.
It is very important for all occupants
to buckle up. Statistics show that
unbelted people are hurt more often
in crashes than those who are
wearing safety belts.
There are important things to know
about wearing a safety belt properly. .
Sit up straight and always keep
your feet on the floor in front
of you. .
Always use the correct buckle
for your seating position. .
Wear the lap part of the belt low
and snug on the hips, just
touching the thighs. In a crash,
this applies force to the strong
pelvic bones and you would be
less likely to slide under the lap
belt. If you slid under it, the belt
would apply force on your
abdomen. This could cause
serious or even fatal injuries.

Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
3-12 Seats and Restraints .
Wear the shoulder belt over the
shoulder and across the chest.
These parts of the body are best
able to take belt restraining
forces. The shoulder belt locks if
there is a sudden stop or crash.
{ WarningYou can be seriously injured,
or even killed, by not wearing
your safety belt properly. .
Never allow the lap or
shoulder belt to become
loose or twisted. .
Never wear the shoulder belt
under both arms or behind
your back. .
Never route the lap or
shoulder belt over an
armrest. Lap-Shoulder Belt All seating positions in the vehicle
have a lap-shoulder belt.
The following instructions explain
how to wear a lap-shoulder belt
properly.
1. Adjust the seat, if the seat is
adjustable, so you can sit up
straight. To see how, see “ Seats ”
in the Index.
2. Pick up the latch plate and pull
the belt across you. Do not let it
get twisted.
The lap-shoulder belt may lock if
you pull the belt across you very
quickly. If this happens, let the
belt go back slightly to unlock it.
Then pull the belt across you
more slowly. If the shoulder portion of a
passenger belt is pulled out all
the way, the child restraint
locking feature may be engaged.
If this happens, let the belt go
back all the way and start again.
Engaging the child restraint
locking feature may affect the
passenger sensing system,
if equipped. See Passenger
Sensing System on page 3-24
for more information.
For the driver and front outboard
seating positions on light duty
vehicles and the rear center

Black plate (15,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-15
Rear safety belt comfort guides may
provide added safety belt comfort
for older children who have
outgrown booster seats and for
some adults. When installed on a
shoulder belt, the comfort guide
positions the shoulder belt away
from the neck and head.
Adjustable comfort guides are
available through your dealer for the
rear outboard seating positions.
Instructions are included with the
guide. Safety Belt Use During
Pregnancy Safety belts work for everyone,
including pregnant women. Like all
occupants, they are more likely to
be seriously injured if they do not
wear safety belts.
A pregnant woman should wear a
lap-shoulder belt, and the lap
portion should be worn as low as
possible, below the rounding,
throughout the pregnancy. The best way to protect the fetus is
to protect the mother. When a safety
belt is worn properly, it is more likely
that the fetus will not be hurt in a
crash. For pregnant women, as for
anyone, the key to making safety
belts effective is wearing them
properly.
Safety Belt Extender If the vehicle's safety belt will fasten
around you, you should use it.
But if a safety belt is not long
enough, your dealer will order you
an extender. When you go in to
order it, take the heaviest coat you
will wear, so the extender will be
long enough for you. To help avoid
personal injury, do not let someone
else use it, and use it only for the
seat it is made to fit. The extender
has been designed for adults. Never
use it for securing child seats. To
wear it, attach it to the regular safety
belt. See the instruction sheet that
comes with the extender.