
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 (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
iv Introduction
Danger, Warnings, and
Cautions
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
{Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: This symbol is shown when
you need to see your owner manual
for additional instructions or
information.
*: This symbol is shown when
you need to see a service manual
for additional instructions or
information. Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. For more
information on the symbol, refer to
the Index.
0:
Adjustable Pedals
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
g:Audio Steering Wheel Controls
or OnStar®(if equipped)
$: Brake System Warning Light
":Charging System
I:Cruise Control
B: Engine Coolant Temperature
O:Exterior Lamps
#:Fog Lamps
.: Fuel Gauge
+:Fuses
3: Headlamp High/Low-Beam
Changer
(: Heated Steering Wheel

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 (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-21
The low tire pressure warning light
alerts to a significant loss in
pressure of one of the vehicle's
tires. If the warning light comes on,
stop as soon as possible and inflate
the tires to the recommended
pressure shown on the Tire and
Loading Information label. See
Vehicle Load Limits on page 9-15.
The warning light will remain on until
the tire pressure is corrected.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
may be an early indicator that the
tire pressures are getting low and
the tires need to be inflated to the
proper pressure.
The TPMS does not replace normal
monthly tire maintenance. Maintain
the correct tire pressures.
SeeTire Pressure Monitor System
on page 10-61.Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays a DIC message when
it is necessary to change the engine
oil and filter. The oil life system
should be reset to 100% only
following an oil change.
Resetting the Oil Life System
1. Display OIL LIFE REMAINING
on the DIC. See Driver
Information Center (DIC) on
page 5-27.
2. Press and hold
Vfor several
seconds. The oil life will change
to 100%.
The oil life system can also be reset
as follows:
1. Turn the ignition to ON/RUN with the engine off.
2. Fully press the accelerator pedal slowly three times within
five seconds. 3. Display the OIL LIFE
REMAINING on the DIC. If the
display shows 100%, the system
is reset.
See Engine Oil Life System on
page 10-11.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or
ethanol fuel containing up to 85%
ethanol (E85). See E85 or FlexFuel
on page 9-65. For all other vehicles,
use only the unleaded gasoline
described under Fuel on page 9-63.
Driving for Better Fuel
Economy
Driving habits can affect fuel
mileage. Here are some driving tips
to get the best fuel economy
possible.
.Avoid fast starts and accelerate
smoothly.
.Brake gradually and avoid
abrupt stops.

Black plate (7,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-7
Remote Vehicle Start
If equipped with the remote start
feature, the climate control system
will come on when the vehicle is
started remotely, depending on the
outside temperature.
The rear defog and heated and
cooled seats, if equipped, may also
come on. SeeHeated and Cooled
Front Seats on page 3-7 and
Vehicle Personalization on
page 5-42.
Laws in some communities may
restrict the use of remote starters.
Check local regulations for any
requirements on remote starting of
vehicles.
Do not use remote start if the
vehicle is low on fuel.
The vehicle cannot be remote
started if:
.The key is in the ignition.
.The hood is not closed.
.There is an emission control
system malfunction and the
malfunction indicator lamp is on.
The engine will turn off during a
remote vehicle start if:
.The coolant temperature gets
too high.
.The oil pressure gets low.
The RKE transmitter range may be
reduced while the vehicle is running.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System on page 2-4 orVehicle
Personalization on page 5-42.
Starting the Engine Using Remote
Start
1. Press and release
Q. 2. Immediately press and hold
/
until the turn signal lamps flash
or for at least four seconds.
When the vehicle starts, the
parking lamps will turn on. The
doors will be locked and the
climate control system may
come on.
The engine will continue to run
for 10 minutes. Repeat the
Steps for 1 and 2 for a
10-minute time extension.
Place the ignition in ON/RUN/
START to operate the vehicle.
Extending Engine Run Time
The engine run time can be
extended by 10 minutes, for a total
of 20 minutes, if during the first
10 minutes Steps 1 and 2 are
repeated while the engine is still
running.
A maximum of two remote starts,
or a single start with an extension,
is allowed between ignition cycles.

Black plate (23,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-23
be some smoke and dust coming
from the vents in the deflated
airbags. Airbag inflation does not
prevent the driver from seeing out of
the windshield or being able to steer
the vehicle, nor does it prevent
people from leaving the vehicle.
{Warning
When an airbag inflates, there
may be dust in the air. This dust
could cause breathing problems
for people with a history of
asthma or other breathing trouble.
To avoid this, everyone in the
vehicle should get out as soon as
it is safe to do so. If you have
breathing problems but cannot
get out of the vehicle after an
airbag inflates, then get fresh air
by opening a window or a door.
If you experience breathing
problems following an airbag
deployment, you should seek
medical attention.The vehicle has a feature that may
automatically unlock the doors, turn
on the interior lamps and hazard
warning flashers, and shut off the
fuel system after the airbags inflate.
The feature may also activate,
without airbag inflation, after an
event that exceeds a predetermined
threshold. You can lock the doors,
and turn off the interior lamps, and
turn off the hazard warning flashers
by using the controls for those
features.
{Warning
A crash severe enough to inflate
the airbags may have also
damaged important functions in
the vehicle, such as the fuel
system, brake and steering
systems, etc. Even if the vehicle
appears to be drivable after a
moderate crash, there may be
(Continued)
Warning (Continued)
concealed damage that could
make it difficult to safely operate
the vehicle.
Use caution if you should attempt
to restart the engine after a crash
has occurred.
In many crashes severe enough to
inflate the airbag, windshields are
broken by vehicle deformation.
Additional windshield breakage may
also occur from the front outboard
passenger airbag.
.Airbags are designed to inflate
only once. After an airbag
inflates, you will need some new
parts for the airbag system.
If you do not get them, the
airbag system will not be there
to help protect you in another
crash. A new system will include
airbag modules and possibly

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-1
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . 5-2
Steering Wheel Controls . . . . . . 5-2
Heated Steering Wheel . . . . . . . 5-3
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Windshield Wiper/Washer . . . . . 5-3
Compass . . . . . . . . . . . . . . . . . . . . . 5-4
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Power Outlets . . . . . . . . . . . . . . . . . 5-5
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . 5-8
Instrument Cluster . . . . . . . . . . . . 5-9
Speedometer . . . . . . . . . . . . . . . . 5-11
Odometer . . . . . . . . . . . . . . . . . . . . 5-11
Trip Odometer . . . . . . . . . . . . . . . 5-11
Tachometer . . . . . . . . . . . . . . . . . . 5-11
Fuel Gauge . . . . . . . . . . . . . . . . . . 5-12
Engine Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . 5-12
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-13 Transmission Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-14
Voltmeter Gauge . . . . . . . . . . . . . 5-15
Safety Belt Reminders . . . . . . . 5-15
Airbag Readiness Light . . . . . . 5-16
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . 5-17
Charging System Light . . . . . . 5-18
Malfunction Indicator Lamp . . . . . . . . . . . . . 5-18
Brake System Warning Light . . . . . . . . . . . . . . . . . . . . . . . 5-21
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . 5-21
Four-Wheel-Drive Light . . . . . . 5-22
Tow/Haul Mode Light . . . . . . . . 5-22
Hill Descent Control Light . . . . 5-22
Lane Departure Warning (LDW) Light . . . . . . . . . . . . . . . . 5-22
Vehicle Ahead Indicator . . . . . . 5-23
Traction Off Light . . . . . . . . . . . . 5-23
StabiliTrak
®OFF Light . . . . . . . 5-23
Traction Control System (TCS)/StabiliTrak
®Light . . . . 5-24
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . 5-24
Tire Pressure Light . . . . . . . . . . 5-25
Engine Oil Pressure Light . . . . 5-25
Low Fuel Warning Light . . . . . . 5-25 Security Light . . . . . . . . . . . . . . . . 5-26
High-Beam On Light . . . . . . . . . 5-26
Front Fog Lamp Light . . . . . . . . 5-26
Lamps On Reminder . . . . . . . . . 5-26
Cruise Control Light . . . . . . . . . 5-27
Door Ajar Light . . . . . . . . . . . . . . 5-27
Information Displays
Driver Information
Center (DIC) . . . . . . . . . . . . . . . 5-27
Vehicle Messages
Vehicle Messages . . . . . . . . . . . 5-31
Battery Voltage and ChargingMessages . . . . . . . . . . . . . . . . . . 5-31
Brake System Messages . . . . 5-32
Compass Messages . . . . . . . . . 5-32
Door Ajar Messages . . . . . . . . . 5-33
Engine Cooling System Messages . . . . . . . . . . . . . . . . . . 5-33
Engine Oil Messages . . . . . . . . 5-34
Engine Power Messages . . . . 5-34
Fuel System Messages . . . . . . 5-35
Key and Lock Messages . . . . . 5-35
Lamp Messages . . . . . . . . . . . . . 5-35
Object Detection System Messages . . . . . . . . . . . . . . . . . . 5-35
Ride Control System Messages . . . . . . . . . . . . . . . . . . 5-36

Black plate (15,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-15
{Caution
Do not drive the vehicle while the
transmission fluid is overheating,
or the transmission can be
damaged. This could lead to
costly repairs that would not be
covered by the warranty.
Voltmeter Gauge
Standard Theme Shown
When the ignition is on, this gauge
indicates the battery voltage. When the engine is running, this
gauge shows the condition of the
charging system. The gauge can
transition from a higher to lower or a
lower to higher reading. This is
normal. If the vehicle is operating
outside the normal operating range,
the charging system light comes on.
See
Charging System Light on
page 5-18 for more information. The
voltmeter gauge may also read
lower when in fuel economy mode.
This is normal.
Readings outside the normal
operating range can also occur
when a large number of electrical
accessories are operating in the
vehicle and the engine is left idling
for an extended period. This
condition is normal since the
charging system is not able to
provide full power at engine idle. As
engine speeds are increased, this
condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power. The vehicle can only be driven for a
short time with the readings outside
the normal operating range. If the
vehicle must be driven, turn off all
accessories, such as the radio and
air conditioner and unplug all
chargers and accessories.
Readings outside the normal
operating range indicate a possible
problem in the electrical system.
Have the vehicle serviced as soon
as possible.
Safety Belt Reminders
Driver Safety Belt Reminder
Light
There is a driver safety belt
reminder light on the instrument
cluster.