
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 (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 (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
{Warning
Leaving 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 (14,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-14 Keys, Doors, and Windows
Exterior Mirrors
Convex Mirrors
{Warning
A 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.
Trailer-Tow Mirrors
If equipped, adjust trailer-tow
mirrors for a clear view of the area
behind you. Manually pull out the
mirror head to extend it for better
visibility when towing a trailer.
The lower portion of the mirror is
convex. A convex mirror's surface is
curved to see more from the driver
seat. The convex mirror can be
adjusted manually to the driver
preferred position for better vision. The mirror may have a turn signal
arrow that flashes in the direction of
the turn or lane change.
If equipped, the mirror housing may
have auxiliary cargo and clearance
lamps. See
Cargo Lamp on
page 6-6 andExterior Lamp
Controls on page 6-1.
Power Mirrors
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.

Black plate (15,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-15
Base Power Mirrors
The power mirror controls are on the
driver door.
1. Press (1) or (2) to select the driver or passenger side mirror.
2. Press one of the four arrows on the control pad to move the
mirror in the desired direction.
3. Adjust each outside mirror so that a little of the vehicle and the
area behind it can be seen. 4. Move the selector switch to the
center position when not
adjusting either outside mirror.
Crew/Double Cab Premium
Shown, Other Models Similar
1. Press (1) or (2) to select the driver or passenger side mirror.
2. Press one of the four arrows on the control pad while the
indicator light on button (1) or (2)
is illuminated, to move the mirror
in the desired direction. 3. Adjust each outside mirror so
that a little of the vehicle and the
area behind it can be seen.
4. Press either (1) or (2) again to deselect the mirror.
If you do not deselect the mirror, the
feature will turn off after about
one minute.
The mirrors may include a memory
function that works with the memory
seats. See Memory Seats on
page 3-5.

Black plate (16,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-16 Keys, Doors, and Windows
Folding Mirrors
Crew/Double Cab Premium
Shown, Other Models Similar
Power Folding
If equipped with power folding
mirrors:
1. Press (2) to fold the mirrors out to the driving position.
2. Press (2) again to fold the mirrors in to the folded position. The mirrors may also include a
memory function that works with the
memory seats. See
Memory Seats
on page 3-5.
Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
.The mirrors are accidentally
obstructed while folding.
.They are accidentally manually
folded/unfolded.
.The mirrors will not stay in the
unfolded position.
.The mirrors vibrate at normal
driving speeds.
Fold and unfold the mirrors three
times using the mirror controls to
reset them to their normal position.
A popping noise may be heard. This
sound is normal after a manual
folding operation.
Manual Folding
If equipped, push the mirror toward
the vehicle to fold. Push the mirror
outward to return to its original
position.
Manually fold the mirrors inward to
prevent damage when going
through an automatic car wash.
Auto Mirror Folding
If equipped, with the ignition off,
press and hold
Qon the RKE
transmitter for approximately
one second to automatically fold the
exterior mirrors. Press and hold
K
on the RKE transmitter for
approximately one second to unfold.
See Remote Keyless Entry (RKE)
System Operation on page 2-4.
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization on
page 5-42.

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
3-6 Seats and Restraints
"1,”"2," orBbefore the stored
positions are reached stops the
recall.
If the vehicle is ON and in P (Park),
press and release “1,” “2,”or
Bto
manually recall the previously
stored memory positions. Placing
the ignition in OFF/LOCK before the
stored positions are reached stops
the recall.
If something has blocked the driver
seat and/or adjustable pedals while
recalling a memory position, the
recall may stop. Remove the
obstruction; then press and hold the
appropriate manual control for the
memory item that is not recalling for
two seconds. Try recalling the
memory position again by pressing
the appropriate memory button.
If the memory position is still not
recalling, see your dealer for
service. Automatically Recalling Memory
Positions (Auto Memory Recall)
The Auto (Automatic) Memory
Recall feature automatically recalls
the current driver
’s previously stored
“1” or“2” position when entering the
vehicle.
If the Auto Memory Recall feature is
enabled in the vehicle
personalization menu, memory “1”
or “2” positions are recalled in the
following ways:
.PressKon the RKE transmitter
and open the driver door.
.PressKon the RKE transmitter
when the driver door is
already open.
See Vehicle Personalization on
page 5-42.
To stop recall movement, press one
of the memory, power mirror or
power seat controls; or press the
adjustable pedal control. If something has blocked the driver
seat and/or the adjustable pedals
while recalling a memory position,
the recall may stop. Remove the
obstruction; then press and hold the
appropriate manual control for the
memory item that is not recalling for
two seconds. Try recalling the
memory position again by opening
the driver door and pressing
Kon
the RKE transmitter. If the memory
position is still not recalling, see
your dealer for service.
RKE Transmitters are not labeled
with a number. If your memory seat
position is stored to "1" or "2" but
this position is not automatically
recalling, then change the stored
position or switch RKE transmitters
with the other driver.
Easy Exit Recall
If programmed on in the vehicle
personalization menu, the easy exit
feature automatically moves the
driver seat, adjustable pedals, and
outside mirrors on some vehicles to
the memory positions saved to the

Black plate (35,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-35
Fuel System Messages
FUEL LEVEL LOW
This message displays and a chime
may sound if the fuel level is low.
Refuel as soon as possible. See
Fuel Gauge on page 5-12andFuel
on page 9-63.
TIGHTEN GAS CAP
This message may display along
with the malfunction indicator lamp
on the instrument cluster if the
vehicle's fuel cap is not tightened
properly. See Malfunction Indicator
Lamp on page 5-18. Reinstall the
fuel cap fully. See Filling the Tank
on page 9-66. The diagnostic
system can determine if the fuel cap
has been left off or improperly
installed. A loose or missing fuel
cap allows fuel to evaporate into the
atmosphere. A few driving trips with
the cap properly installed should
turn this light and message off.
Key and Lock Messages
REPLACE BATTERY IN
REMOTE KEY
This message displays if a Remote
Keyless Entry (RKE) transmitter
battery is low. The battery needs to
be replaced in the transmitter. See
“Battery Replacement” under
Remote Keyless Entry (RKE)
System Operation on page 2-4.
Lamp Messages
TURN SIGNAL ON
This message displays and a chime
sounds if a turn signal is left on for
1.2 km (0.75 mi). Move the turn
signal lever to the off position.
Object Detection System
Messages
FORWARD COLLISION
ALERT OFF
This message displays when the
Forward Collision Alert has been
turned off.
FRONT CAMERA BLOCKED
CLEAN WINDSHIELD
This message displays when the
camera is blocked. Cleaning the
outside of the windshield behind the
rearview mirror may correct the
issue. The Lane Departure Warning
(LDW) system and Forward
Collision Alert (FCA) will not
operate.
LANE DEPARTURE WARNING
UNAVAILABLE
This message displays when
attempting to activate the Lane
Departure Warning (LDW) system