
Black plate (91,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-91
This has the effect of reducing the
load on the front. However, the front
GAWR, rear GAWR, and Gross
Vehicle Weight Rating (GVWR) must
never be exceeded.
{Warning
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front gross axle weight rating
(GAWR) but not have enough
weight on the rear axle to have
proper braking performance. If the
brakes cannot work properly, you
could have a crash. To help the
brakes work properly when a
snow plow is installed, always
follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio, even
though the actual front weight(Continued)
Warning (Continued)
may be less than the front
GAWR, and the total vehicle
weight is less than the gross
vehicle weight rating (GVWR).
Maintaining a proper front and
rear weight distribution ratio is
necessary to provide proper
braking performance.
Total vehicle reserve capacity is the
difference between the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount of
weight that can be added to the
vehicle before reaching the GVWR.
Keep in mind that reserve capacity
numbers are intended as a guide
when selecting the amount of
equipment or cargo the truck can
carry. If unsure of the vehicle's front,
rear, or total weight, go to a weigh
station and weigh the vehicle. Your
dealer can also help with this. The total vehicle reserve capacity
for the vehicle can be found in the
lower right corner of the
Certification/Tire label as shown
previously.
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
see
Vehicle Load Limits on
page 9-15.
Emergency Roof Lamp
Provisions
Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp on
page 6-5 for switch location.

Black plate (49,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-49
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Number Usage
1 Accessory Power Outlet 3
2 Accessory Power Outlet 4
7 Body Control Module 4
8 Body Control Module 8
9 Rear Seat Entertainment
10 Cargo Lamp
15 Steering Wheel Controls
18 Radio
19 Spare
20 Sunroof
23 Airbag/Info Number Usage
26 Export/Power Take Off/SEO Battery 1
27 Obstacle Detection/ USB Ports
28 Body Control Module 2
32 SEO Battery 2
35 AC Inverter
36 Amplifier
37 Spare
39 Rear Sliding Window
42 Right Door Window Motor
43 Front Blower
44 SEO
45 Body Control Module 6
46 Body Control Module 7
47 Passenger Seat Number Usage
50 Retained Accessory Power/Accessory
51 Rear Sliding Window Open
52 Rear Sliding Window Close

Black plate (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-4 Service and Maintenance
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. SeeExterior
Care on page 10-96. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10-35.
.Check tire inflation pressures.
See Tire Pressure on
page 10-59.
.Inspect tire wear. See Tire
Inspection on page 10-65.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10-15.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear
at least once a year. See
Exterior Care on page 10-96.
Lubricate the suspension and steering components at least
every other oil change.
(If equipped with grease fittings)
.Check restraint system
components. See
Safety System
Check on page 3-16.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10-96.
.Check starter switch. See Starter
Switch Check on page 10-33.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10-34.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10-34.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10-34.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2-22.
.Verify spare tire key lock
operation and lubricate as
needed. See Tire Changing on
page 10-76.

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
A
Accessories andModifications . . . . . . . . . . . . . . . . . 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 theVehicle . . . . . . . . . . . . . . . . . . . . . . 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 ControlFunction Check . . . . . . . . . . . 10-34
Auxiliary Roof Mounted Lamp . . . . . . . . . . . 6-5
Axle, Front . . . . . . . . . . . . . . . . . . . . 10-30
Axle, Rear . . . . . . . . . . . . . . . . . . . . 10-31

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-6 INDEX
H
Halogen Bulbs . . . . . . . . . . . . . . . . 10-36
Hazard Warning Flashers . . . . . . . 6-4
Head Restraints . . . . . . . . . . . . . . . . 3-2
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . 10-36
Automatic . . . . . . . . . . . . . . . . . . . . . . 6-3
Bulb Replacement . . . . . . . . . . 10-36
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . . 6-3
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-36
High-Beam On Light . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lamps On Reminder . . . . . . . . . 5-26
Heated Steering Wheel . . . . . . . . . . . . . . . . 5-3
Heated and Cooled Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Heated Mirrors . . . . . . . . . . . . . . . . . 2-17
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 9-28
High-Beam On Light . . . . . . . . . . . 5-26 High-Speed Operation . . . . . . . . 10-60
Hill and Mountain Roads . . . . . . . 9-11
Hill Descent Control (HDC) . . . . 9-51
Hill Descent Control Light . . . . . . 5-22
Hill Start Assist (HSA) . . . . . . . . . 9-48
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . . . 3-11
I
Idle SystemFast . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
Ignition Positions . . . . . . . . . . . . . . 9-24
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 10-34
Immobilizer . . . . . . . . . . . . . . . . . . . . 2-12
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . 5-23
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . 3-32
Infotainment . . . . . . . . . . . . . . . . . . . . 7-1
Infotainment System . . . . . . . . . . 13-15
Instrument Cluster . . . . . . . . . . . . . . 5-9
Instrument Panel Storage Area . . . . . . . . . . . . . . . . . . 4-1 Interior Rearview Mirrors . . . . . . . 2-19
Introduction . . . . . . . . . . . . . . . . . . . . . . . iii
J
Jump Starting . . . . . . . . . . . . . . . . . 10-87
K
Key and Lock Messages . . . . . . . 5-35
Keyless Entry
Remote (RKE) System . . . . . . . . 2-4
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
L
Labeling, Tire Sidewall . . . . . . . . 10-52
Lamps
Auxiliary RoofMounted Lamp . . . . . . . . . . . . . . . 6-5
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Daytime Running (DRL) . . . . . . . 6-3
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Exterior Controls . . . . . . . . . . . . . . . 6-1
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . . 6-2
Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Malfunction Indicator . . . . . . . . . 5-18

Black plate (10,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-10 INDEX
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Remote Vehicle Start . . . . . . . . . . . 2-7
Replacement Glass . . . . . . . . . . . . . . . . . . . . . . . 10-35
Replacement Bulbs . . . . . . . . . . . 10-40
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . 3-30
Maintenance . . . . . . . . . . . . . . . . .11-14
Replacing Airbag System . . . . . . 3-30
Replacing LATCH System Parts after a Crash . . . . . . . . . . . 3-45
Replacing Safety Belt System Parts after a Crash . . . 3-16
Reporting Safety Defects Canadian Government . . . . . . 13-13
General Motors . . . . . . . . . . . . . 13-13
U.S. Government . . . . . . . . . . . 13-13
Restraints Where to Put . . . . . . . . . . . . . . . . . 3-37
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . . 9-29
Reverse Tilt Mirrors . . . . . . . . . . . . 2-18
Ride Control Systems Messages . . . . . . . . . . . . . . . . . . . . 5-36 Roads
Driving, Wet . . . . . . . . . . . . . . . . . . 9-11
Roadside Assistance Program . . . . . . . . . . . . . . . . . . . . . . 13-5
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . 2-22
Rotation, Tires . . . . . . . . . . . . . . . . 10-65
Routing, Engine Drive Belt . . . . . 12-4
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . . 9-33
S
Safety Belts . . . . . . . . . . . . . . . . . . . 3-10Care . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Extender . . . . . . . . . . . . . . . . . . . . . . 3-15
How to Wear Safety BeltsProperly . . . . . . . . . . . . . . . . . . . . . 3-11
Lap-Shoulder Belt . . . . . . . . . . . . 3-12
Messages . . . . . . . . . . . . . . . . . . . . 5-37
Reminders . . . . . . . . . . . . . . . . . . . . 5-15
Replacing after a Crash . . . . . . 3-16
Use During Pregnancy . . . . . . . . 3-15 Safety Defects Reporting
Canadian Government . . . . . . 13-13
General Motors . . . . . . . . . . . . . 13-13
U.S. Government . . . . . . . . . . . 13-13
Safety Locks . . . . . . . . . . . . . . . . . . . . 2-9
Safety System Check . . . . . . . . . . 3-16
Scheduling Appointments . . . . . . 13-7
Seats Head Restraints . . . . . . . . . . . . . . . 3-2
Lumbar Adjustment, Front . . . . . 3-3
Memory . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Power Adjustment, Front . . . . . . 3-3
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Reclining Seatbacks . . . . . . . . . . . 3-4
Securing Child Restraints . . . . . . . . . . . . . . 3-45, 3-47
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Messages . . . . . . . . . . . . . . . . . . . . 5-38
OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-3
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 2-11
Vehicle Alarm . . . . . . . . . . . . . . . . . 2-11

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-11
Service . . . . . . . . . . . . . . . . . . . . . . . . . 8-6Accessories and
Modifications . . . . . . . . . . . . . . . . 10-3
Doing Your Own Work . . . . . . . . 10-3
Engine Soon Light . . . . . . . . . . . . 5-18
Maintenance Records . . . . . . .11-16
Maintenance, General Information . . . . . . . . . . . . . . . . . . 11-1
Parts Identification Label . . . . . 12-1
Publications Ordering Information . . . . . . . . . . . . . . . . .13-11
Scheduling Appointments . . . . . 13-7
Services Special Application . . . . . . . . . . . 11-8
Servicing the Airbag . . . . . . . . . . . 3-28
Shift Lock Control Function Check, Automatic
Transmission . . . . . . . . . . . . . . . . 10-34
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . 9-30
Out of Park . . . . . . . . . . . . . . . . . . . 9-31
Signals, Turn and Lane-Change . . . . . . . . . . . . . . . . . 6-4
Snow Plow . . . . . . . . . . . . . . . . . . . . 9-88
Special Application Services . . . 11-8 Specifications and
Capacities . . . . . . . . . . . . . . . . . . . . 12-2
Speedometer . . . . . . . . . . . . . . . . . . 5-11
StabiliTrak OFF Light . . . . . . . . . . . . . . . . . . . . . 5-23
Start Assist, Hills . . . . . . . . . . . . . . 9-48
Start Vehicle, Remote . . . . . . . . . . 2-7
Starter Switch Check . . . . . . . . . 10-33
Starting the Engine . . . . . . . . . . . . 9-26
Steering . . . . . . . . . . . . . . . . . . . . . . . . 9-4 Fluid, Power . . . . . . . . . . . . . . . . 10-24
Heated Wheel . . . . . . . . . . . . . . . . . 5-3
Wheel Adjustment . . . . . . . . . . . . . 5-2
Wheel Controls . . . . . . . . . . . . . . . . 5-2
Steering System Messages . . . . 5-38
Stoplamps and Back-up Lamps Bulb Replacement . . . . . . . . . . 10-37
Storage Areas Center Console . . . . . . . . . . . . . . . . 4-2
Floor Console . . . . . . . . . . . . . . . . . 4-3
Glove Box . . . . . . . . . . . . . . . . . . . . . 4-1
Instrument Panel . . . . . . . . . . . . . . 4-1
Sunglasses . . . . . . . . . . . . . . . . . . . . 4-2
Storage Compartments . . . . . . . . . 4-1
Stuck Vehicle . . . . . . . . . . . . . . . . . . 9-14
Sun Visors . . . . . . . . . . . . . . . . . . . . . 2-22 Sunglass Storage . . . . . . . . . . . . . . . 4-2
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . iv
System
Forward CollisionAlert (FCA) . . . . . . . . . . . . . . . . . . 9-59
Infotainment . . . . . . . . . . . . 7-1, 13-15
Noise Control . . . . . . . . . . . . . . . 10-32
Systems Driver Assistance . . . . . . . . . . . . . 9-55
T
Tachometer . . . . . . . . . . . . . . . . . . . . 5-11
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 2-10
TaillampsBulb Replacement . . . . . . . . . . 10-37
Text Telephone (TTY) Users . . . 13-4
Theft-Deterrent Systems . . . . . . . 2-13 Immobilizer . . . . . . . . . . . . . . . . . . . 2-12
Throttle, Adjustable . . . . . . . . . . . . 9-23
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 10-50 All-Season . . . . . . . . . . . . . . . . . . 10-51
All-Terrain . . . . . . . . . . . . . . . . . . 10-52
Buying New Tires . . . . . . . . . . . 10-69
Chains . . . . . . . . . . . . . . . . . . . . . . 10-74