
Black plate (10,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-10 Service and Maintenance Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road. .
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking. .
With a multi-point inspection,
your dealer can check the lamps
and note any concerns. Shocks and Struts
Shocks and struts help aid in control
for a smoother ride. .
Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear. .
As part of the multi-point
inspection, trained dealer
technicians can visually inspect
the shocks and struts for signs
of leaking, blown seals,
or damage, and can advise
when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money and fuel,
and can reduce the risk of tire
failure. .
Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord
or fabric showing through the rubber; cracks or cuts in the
tread or sidewall; or a bulge or
split in the tire. .
Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also
provide tire/wheel balancing
services to ensure smooth
vehicle operation at all speeds.
Your dealer sells and services
name brand tires.
Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle ’ s interior and
exterior, see Interior Care on
page 10-101 and Exterior Care on
page 10-96 .

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-1
AAccessories and
Modifications . . . . . . . . . . . . . . . . . 10-3
Accessory Power . . . . . . . . . . . . . . 9-29
Active Fuel Management ®
. . . . . 9-32
Add-On Electrical
Equipment . . . . . . . . . . . . . . . . . . . 9-88
Adding a Snow Plow or
Similar Equipment . . . . . . . . . . . . 9-88
Additional Information
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 14-6
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . . 11-9
Adjustable Throttle and
Brake Pedal . . . . . . . . . . . . . . . . . . 9-23
Adjustments
Lumbar, Front Seats . . . . . . . . . . . 3-3
Air Cleaner/Filter, Engine . . . . . 10-15
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . 8-5
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 8-4 Airbag System
Check . . . . . . . . . . . . . . . . . . . . . . . . 3-29
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . 3-22
Passenger Sensing
System . . . . . . . . . . . . . . . . . . . . . . 3-24
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-22
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . 3-22
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-20
Where Are the Airbags? . . . . . . 3-18
Airbags
Adding Equipment to the
Vehicle . . . . . . . . . . . . . . . . . . . . . . 3-28
Passenger Status Indicator . . . 5-17
Readiness Light . . . . . . . . . . . . . . 5-16
Servicing Airbag-Equipped
Vehicles . . . . . . . . . . . . . . . . . . . . . 3-28
System Check . . . . . . . . . . . . . . . . 3-17
Alarm
Vehicle Security . . . . . . . . . . . . . . 2-11
All-Season Tires . . . . . . . . . . . . . . 10-51
All-Terrain Tires . . . . . . . . . . . . . . . 10-52 Antilock Brake
System (ABS) . . . . . . . . . . . . . . . . 9-46
Warning Light . . . . . . . . . . . . . . . . . 5-21
Appearance Care
Exterior . . . . . . . . . . . . . . . . . . . . . 10-96
Interior . . . . . . . . . . . . . . . . . . . . . 10-101
Assistance Program,
Roadside . . . . . . . . . . . . . . . . . . . . . 13-5
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . . 9-59
Assistance Systems for
Parking and Backing . . . . . . . . . 9-56
Automatic
Dimming Mirrors . . . . . . . . . . . . . . 2-17
Door Locks . . . . . . . . . . . . . . . . . . . . 2-9
Headlamp System . . . . . . . . . . . . . 6-3
Transmission . . . . . . . . . . . . . . . . . 9-33
Transmission Fluid . . 10-12, 10-15
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 9-36
Shift Lock Control
Function Check . . . . . . . . . . . 10-34
Auxiliary
Roof Mounted Lamp . . . . . . . . . . . 6-5
Axle, Front . . . . . . . . . . . . . . . . . . . . 10-30
Axle, Rear . . . . . . . . . . . . . . . . . . . . 10-31

Black plate (2,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-2 INDEX
BBattery . . . . . . . . . . . . . . . . . . . . . . . 10-29
Jump Starting . . . . . . . . . . . . . . . 10-87
Load Management . . . . . . . . . . . . . 6-8
Power Protection . . . . . . . . . . . . . . 6-9
Voltage and Charging
Messages . . . . . . . . . . . . . . . . . . . 5-31
Blade Replacement, Wiper . . . 10-35
Blind Spot Mirrors . . . . . . . . . . . . . 2-17
Brake
Pedal and Adjustable
Throttle . . . . . . . . . . . . . . . . . . . . . . 9-23
System Warning Light . . . . . . . . 5-21
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 10-26
Antilock . . . . . . . . . . . . . . . . . . . . . . . 9-46
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 9-48
Fluid . . . . . . . . . . . . . . . . . . . . . . . . 10-27
Parking . . . . . . . . . . . . . . . . . . . . . . . 9-47
System Messages . . . . . . . . . . . . 5-32
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
Break-In, New Vehicle . . . . . . . . . 9-23 Bulb Replacement . . . . . . . . . . . . 10-40
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . 10-39
Halogen Bulbs . . . . . . . . . . . . . . 10-36
Headlamp Aiming . . . . . . . . . . . 10-36
Headlamps . . . . . . . . . . . . . . . . . 10-36
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-36
Taillamps, Turn Signal,
Stoplamps, and
Back-up Lamps . . . . . . . . . . . 10-37
Buying New Tires . . . . . . . . . . . . . 10-69
C Calibration . . . . . . . . . . . . . . . . . . . . . . 5-4
California
Fuel Requirements . . . . . . . . . . . 9-64
Perchlorate Materials
Requirements . . . . . . . . . . . . . . . 10-3
Warning . . . . . . . . . . . . . . . . . . . . . . 10-2
Canadian Vehicle Owners . . . . . . . . iii
Capacities and
Specifications . . . . . . . . . . . . . . . . 12-2 Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . 9-32
Tailgate . . . . . . . . . . . . . . . . . . . . . . . 2-10
Winter Driving . . . . . . . . . . . . . . . . 9-12
Cargo
Tie-Downs . . . . . . . . . . . . . . . . . . . . . 4-3
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 6-6
Cautions, Danger, and
Warnings . . . . . . . . . . . . . . . . . . . . . . . . iv
Center Console Storage . . . . . . . . 4-2
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 10-39
Chains, Tire . . . . . . . . . . . . . . . . . . 10-74
Charging System Light . . . . . . . . 5-18
Check
Engine Light . . . . . . . . . . . . . . . . . . 5-18
Ignition
Transmission Lock . . . . . . . . 10-34

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-5FlexFuel
E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-65
Floor Console Storage . . . . . . . . . . 4-3
Floor Mats . . . . . . . . . . . . . . . . . . .10-105
Fluid
Automatic
Transmission . . . . . . . 10-12, 10-15
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-27
Four-Wheel Drive
Transfer Case . . . . . . . . . . . . . . . 9-40
Power Steering . . . . . . . . . . . . . 10-24
Washer . . . . . . . . . . . . . . . . . . . . . 10-25
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 6-5
Bulb Replacement . . . . . . . . . . 10-37
Folding Mirrors . . . . . . . . . . . . . . . . 2-16
Forward Collision Alert
(FCA) System . . . . . . . . . . . . . . . . 9-59
Four-Wheel Drive . . . . . . . 9-40, 10-29
Four-Wheel-Drive Light . . . . . . . . 5-22
Frequency Statement
Radio . . . . . . . . . . . . . . . . . . . . . . . 13-12
Front Axle . . . . . . . . . . . . . . . . . . . . 10-30 Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Front Seats
Heated and Cooled . . . . . . . . . . . . 3-7
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Additives . . . . . . . . . . . . . . . . . . . . . 9-64
Economy Driving . . . . . . . . . . . . . 1-21
Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . 9-67
Filling the Tank . . . . . . . . . . . . . . . 9-66
Foreign Countries . . . . . . . . . . . . 9-64
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Low Fuel Warning Light . . . . . . . 5-25
Management, Active . . . . . . . . . . 9-32
Requirements, California . . . . . 9-64
System Messages . . . . . . . . . . . . 5-35
Full-Size Spare Tire . . . . . . . . . . 10-86
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . 10-41
Instrument Panel
Fuse Block . . . . . . . . . 10-45, 10-48 G Garage Door Opener . . . . . . . . . . 5-49
Programming . . . . . . . . . . . . . . . . . 5-49
Gauges
Engine Coolant
Temperature . . . . . . . . . . . . . . . . 5-13
Engine Oil Pressure . . . . . . . . . . 5-12
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Odometer . . . . . . . . . . . . . . . . . . . . . 5-11
Speedometer . . . . . . . . . . . . . . . . . 5-11
Tachometer . . . . . . . . . . . . . . . . . . . 5-11
Transmission Temperature . . . . 5-14
Trip Odometer . . . . . . . . . . . . . . . . 5-11
Voltmeter . . . . . . . . . . . . . . . . . . . . . 5-15
Warning Lights and
Indicators . . . . . . . . . . . . . . . . . . . . 5-8
General Information
Service and Maintenance . . . . . 11-1
Towing . . . . . . . . . . . . . . . . . . . . . . . . 9-68
Vehicle Care . . . . . . . . . . . . . . . . . . 10-2
Glass Replacement . . . . . . . . . . . 10-35
Glove Box . . . . . . . . . . . . . . . . . . . . . . 4-1
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . 13-5

Black plate (7,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-7Lamps (cont'd)
Messages . . . . . . . . . . . . . . . . . . . . 5-35
On Reminder . . . . . . . . . . . . . . . . . 5-26
Reading . . . . . . . . . . . . . . . . . . . . . . . 6-7
Lane Departure
Warning (LDW) . . . . . . . . . . . . . . . 9-61
Lane Departure Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
Lap-Shoulder Belt . . . . . . . . . . . . . 3-12
LATCH System
Replacing Parts after a
Crash . . . . . . . . . . . . . . . . . . . . . . . 3-45
LATCH, Lower Anchors and
Tethers for Children . . . . . . . . . . 3-38
LED Lighting . . . . . . . . . . . . . . . . . . 10-36
Light
Hill Decent Control . . . . . . . . . . . 5-22
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Illumination Control . . . . . . . . . . . . 6-6
LED . . . . . . . . . . . . . . . . . . . . . . . . 10-36
Lights
Airbag Readiness . . . . . . . . . . . . . 5-16
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 5-21
Brake System Warning . . . . . . . 5-21 Lights (cont'd)
Charging System . . . . . . . . . . . . . 5-18
Cruise Control . . . . . . . . . . . . . . . . 5-27
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-27
Engine Coolant
Temperature Warning . . . . . . . 5-24
Engine Oil Pressure . . . . . . . . . . 5-25
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
Four-Wheel-Drive . . . . . . . . . . . . . 5-22
Front Fog Lamp . . . . . . . . . . . . . . 5-26
High-Beam On . . . . . . . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lane Departure Warning . . . . . . 5-22
Low Fuel Warning . . . . . . . . . . . . 5-25
Safety Belt Reminders . . . . . . . . 5-15
Security . . . . . . . . . . . . . . . . . . . . . . 5-26
StabiliTrak ®
OFF . . . . . . . . . . . . . 5-23
Tire Pressure . . . . . . . . . . . . . . . . . 5-25
Tow/Haul Mode . . . . . . . . . . . . . . . 5-22
Traction Control System
(TCS)/StabiliTrak ®
. . . . . . . . . . 5-24
Traction Off . . . . . . . . . . . . . . . . . . . 5-23
Locking Rear Axle . . . . . . . . . . . . . 9-52
Locks
Automatic Door . . . . . . . . . . . . . . . . 2-9
Delayed Locking . . . . . . . . . . . . . . . 2-9
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8 Locks (cont'd)
Lockout Protection . . . . . . . . . . . . . 2-9
Power Door . . . . . . . . . . . . . . . . . . . . 2-9
Safety . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Loss of Control . . . . . . . . . . . . . . . . . 9-5
Low Fuel Warning Light . . . . . . . . 5-25
Low-Profile Tires . . . . . . . . . . . . . . 10-51
Lower Anchors and Tethers
for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . 3-38
Lumbar Adjustment . . . . . . . . . . . . . 3-3
Front Seats . . . . . . . . . . . . . . . . . . . . 3-3
M Maintenance
Records . . . . . . . . . . . . . . . . . . . . .11-16
Maintenance and Care
Additional . . . . . . . . . . . . . . . . . . . . . 11-9
Maintenance Schedule . . . . . . . . 11-3
Recommended Fluids
and Lubricants . . . . . . . . . . . . .11-12
Transfer Case . . . . . . . . . . . . . . . . 9-40
Malfunction Indicator Lamp . . . . 5-18
Manual Mode . . . . . . . . . . . . . . . . . . 9-36
Memory Features . . . . . . . . . . . . . . . 1-8
Memory Seats . . . . . . . . . . . . . . . . . . 3-5

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-8 INDEX Messages
Airbag System . . . . . . . . . . . . . . . . 5-37
Battery Voltage and
Charging . . . . . . . . . . . . . . . . . . . . 5-31
Brake System . . . . . . . . . . . . . . . . 5-32
Compass . . . . . . . . . . . . . . . . . . . . . 5-32
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-33
Engine Cooling System . . . . . . . 5-33
Engine Oil . . . . . . . . . . . . . . . . . . . . 5-34
Engine Power . . . . . . . . . . . . . . . . 5-34
Fuel System . . . . . . . . . . . . . . . . . . 5-35
Key and Lock . . . . . . . . . . . . . . . . . 5-35
Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
Object Detection System . . . . . 5-35
Ride Control System . . . . . . . . . . 5-36
Safety Belt . . . . . . . . . . . . . . . . . . . . 5-37
Security . . . . . . . . . . . . . . . . . . . . . . 5-38
Steering System . . . . . . . . . . . . . . 5-38
Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
Transmission . . . . . . . . . . . . . . . . . 5-39
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-31
Vehicle Reminder . . . . . . . . . . . . . 5-41
Vehicle Speed . . . . . . . . . . . . . . . . 5-42
Washer Fluid . . . . . . . . . . . . . . . . . 5-42 Mirrors
Automatic Dimming . . . . . . . . . . . 2-17
Automatic Dimming
Rearview . . . . . . . . . . . . . . . . . . . . 2-19
Blind Spot . . . . . . . . . . . . . . . . . . . . 2-17
Convex . . . . . . . . . . . . . . . . . . . . . . . 2-14
Folding . . . . . . . . . . . . . . . . . . . . . . . 2-16
Heated . . . . . . . . . . . . . . . . . . . . . . . 2-17
Power . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Tilt in Reverse . . . . . . . . . . . . . . . . 2-18
Trailer Tow . . . . . . . . . . . . . . . . . . . . 2-14
Mirrors, Interior Rearview . . . . . . 2-19
Monitor System, Tire
Pressure . . . . . . . . . . . . . . . . . . . . 10-61
N Navigation
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 14-3
New Vehicle Break-In . . . . . . . . . . 9-23
Noise Control System . . . . . . . . 10-32 O Object Detection System
Messages . . . . . . . . . . . . . . . . . . . . 5-35
Odometer . . . . . . . . . . . . . . . . . . . . . . 5-11
Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 9-6
Driving . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Recovery . . . . . . . . . . . . . . . . . . . . . . 9-5
Oil
Engine . . . . . . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . .10-11
Engine Oil Pressure
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-12
Messages . . . . . . . . . . . . . . . . . . . . 5-34
Pressure Light . . . . . . . . . . . . . . . . 5-25
Older Children, Restraints . . . . . 3-30
Online Owner Center . . . . . . . . . . 13-4
OnStar . . . . . . . . . . . . . . . . . . . . . . . 13-15
OnStar ®
System, In Brief . . . . . . . . . . . . . . 1-22
OnStar ®
Additional
Information . . . . . . . . . . . . . . . . . . . 14-6
OnStar ®
Connections . . . . . . . . . . 14-4
OnStar ®
Emergency . . . . . . . . . . . 14-2
OnStar ®
Navigation . . . . . . . . . . . . 14-3
OnStar ®
Overview . . . . . . . . . . . . . 14-1

Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-13Vehicle (cont'd)
Messages . . . . . . . . . . . . . . . . . . . . 5-31
Personalization . . . . . . . . . . . . . . . 5-42
Reminder Messages . . . . . . . . . . 5-41
Remote Start . . . . . . . . . . . . . . . . . . 2-7
Security . . . . . . . . . . . . . . . . . . . . . . 2-11
Speed Messages . . . . . . . . . . . . . 5-42
Towing . . . . . . . . . . . . . . . . . . . . . . 10-91
Vehicle Ahead Indicator . . . . . . . 5-23
Vehicle Care
Tire Pressure . . . . . . . . . . . . . . . 10-59
Vehicle Data Recording
and Privacy . . . . . . . . . . . . . . . . . 13-14
Vehicle Diagnostics
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 14-6
Ventilation, Air . . . . . . . . . . . . . . . . . . 8-4
Visors . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Voltmeter Gauge . . . . . . . . . . . . . . 5-15 W Warning
Brake System Light . . . . . . . . . . . 5-21
Lane Departure (LDW) . . . . . . . 9-61
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . . 5-8
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . iv
Cautions and Danger . . . . . . . . . . . .iv
Hazard Flashers . . . . . . . . . . . . . . . 6-4
Washer Fluid . . . . . . . . . . . . . . . . . 10-25
Messages . . . . . . . . . . . . . . . . . . . . 5-42
Wheels
Alignment and Tire
Balance . . . . . . . . . . . . . . . . . . . 10-72
Different Size . . . . . . . . . . . . . . . 10-70
Replacement . . . . . . . . . . . . . . . 10-73
When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-68
Where to Put the Restraint . . . . 3-37 Windows . . . . . . . . . . . . . . . . . . . . . . 2-19
Power . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Windshield
Wiper/Washer . . . . . . . . . . . . . . . . . 5-3
Winter
Driving . . . . . . . . . . . . . . . . . . . . . . . . 9-12
Winter Tires . . . . . . . . . . . . . . . . . . 10-51
Wiper Blade Replacement . . . . 10-35