
Black plate (100,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-100 Vehicle Care
Tires
Use a stiff brush with tire cleaner to
clean the tires.
{Caution
Using petroleum-based tire
dressing products on the vehicle
may damage the paint finish and/
or tires. When applying a tire
dressing, always wipe off any
overspray from all painted
surfaces on the vehicle.
Wheels and Trim—Aluminum
or Chrome
Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied.
{Caution
Chrome wheels and other chrome
trim may be damaged if the
vehicle is not washed after driving
on roads that have been sprayed
with magnesium, calcium,
or sodium chloride. These
chlorides are used on roads for
conditions such as ice and dust.
Always wash the chrome with
soap and water after exposure.
{Caution
To avoid surface damage, do not
use strong soaps, chemicals,
abrasive polishes, cleaners,
brushes, or cleaners that contain
acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
(Continued)
Caution (Continued)
automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
hook-up, binding, leaks, cracks,
chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
1500 Series vehicles, at least every
other oil change lubricate the outer
tie rod ends.

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-8 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services —Severe
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels.
Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
(2) Check all fuel and vapor lines
and hoses for proper hook-up,
routing, and condition.
(3) Or every four years, whichever
comes first.
(4) Do not directly power wash the
transfer case output seals. High
pressure water can overcome the
seals and contaminate the transfer
case fluid. Contaminated fluid will
decrease the life of the transfer
case and should be replaced. (5)
Extreme service. For vehicles
mainly driven off-road in four-wheel
drive or used in farming, mining,
forestry, Department of Natural
Resources (DNR), or snow plowing.
(6) Or every five years, whichever
comes first. See Cooling System on
page 10-17.
(7) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(8) Or every three years, whichever
comes first.Special Application
Services
.Severe Commercial Use
Vehicles Only: Lubricate chassis
components every 5 000 km/
3,000 mi.
.Have underbody flushing service
performed. See "Underbody
Maintenance" in Exterior Care
on page 10-96.

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 andExterior Care on
page 10-96.

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-11
Wheel Alignment
Wheel alignment is critical for
ensuring that the tires deliver
optimal wear and performance.
.Signs that the alignment may
need to be adjusted include
pulling, improper vehicle
handling, or unusual tire wear.
.Your dealer has the required
equipment to ensure proper
wheel alignment.
Windshield
For safety, appearance, and the
best viewing, keep the windshield
clean and clear.
.Signs of damage include
scratches, cracks, and chips.
.Trained dealer technicians can
inspect the windshield and
recommend proper replacement
if needed. Wiper Blades
Wiper blades need to be cleaned
and kept in good condition to
provide a clear view.
.Signs of wear include streaking,
skipping across the windshield,
and worn or split rubber.
.Trained dealer technicians can
check the wiper blades and
replace them when needed.

Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-13
UsageFluid/Lubricant
Automatic Transmission (6.2L with 8-Speed transmission) DEXRON
®-HP Automatic Transmission Fluid (GM Part No. 19300536, in
Canada 19300537).
Transfer Case (Four-Wheel Drive) DEXRON
®-VI Automatic Transmission Fluid.
Floor Shift Linkage Lubriplate Lubricant Aerosol (GM Part No. 89021668, in Canada 89021674) or lubricant meeting requirements of NLGI #2 Category LB or GC-LB.
Chassis Lubrication Chassis Lubricant (GM Part No. 12377985, in Canada 88901242) or lubricant meeting requirements of NLGI #2, Category LB or GC-LB.
Front Axle (1500 Series) –
Four-Wheel Drive SAE 80W-90 Axle Lubricant (GM Part No. 89021671, in
Canada 89021672).
Rear Axle (1500) SAE 75W-85 Synthetic Axle Lubricant (GM Part No. 19300457, in Canada 19300458).
Front and Rear Axle (2500/3500) SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in Canada 89021678).
Front Axle Driveshaft Splines (All
1500/2500/3500 Series) and Rear Axle Driveshaft Splines (All 1500
Series with Automatic Transmission) Spline Lubricant, Special Lubricant (GM Part No. 19257121, in
Canada 19257122).

Black plate (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Technical Data 12-3
ApplicationCapacities
Metric English
Fuel Tank
1500 Series 98.4 L 26.0 gal
2500 Series and 3500 Series Standard Box 136.3 L 36.0 gal
3500 Series Long Box 136.3 L 36.0 gal
Transfer Case Fluid 1.5 L 1.6 qt
Wheel Nut Torque 190 Y140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck fluid level after filling.
Engine Specifications
Engine VIN CodeSpark Plug Gap
5.3L V8 (L83) C0.95–1.10 mm (0.037–
0.043 in)
6.0L V8 (L96) G0.95–1.10 mm (0.037–
0.043 in)
6.2L V8 (L86) J0.95–1.10 mm (0.037–
0.043 in)

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Customer Information 13-5
GMC Owner Centre (Canada)
gmcowner.ca
Take a trip to the GMC Owner
Centre:
.Chat live with online help
representatives.
.Use the Vehicle Tools section.
.Access third party enthusiast
sites and social media networks.
.Locate owner resources such as
lease-end, financing, and
warranty information.
.Retrieve your favorite articles,
quizzes, tips, and multimedia
galleries organized into the
Features and Auto Care
Sections.
.Download the owner manual for
your vehicle, quickly and easily.
.Find the GMC-recommended
maintenance services for your
vehicle.
GM Mobility
Reimbursement Program
This program is available to
qualified applicants for cost
reimbursement of eligible
aftermarket adaptive equipment
required for the vehicle, such as
hand controls or a wheelchair/
scooter lift for the vehicle.
For more information on the limited
offer, visit www.gmmobility.com or
call the GM Mobility Assistance
Center at 1-800-323-9935. Text
Telephone (TTY) users, call
1-800-833-9935.General Motors of Canada also has
a Mobility Program. Visit www.gm.ca
or call 1-800-GM-DRIVE (463-7483)
for details. TTY users call
1-800-263-3830.
Roadside Assistance
Program
For U.S.-purchased vehicles, call
1-888-881-3302; (Text Telephone
(TTY): 1-888-889-2438).
For Canadian-purchased vehicles,
call 1-800-268-6800.
Service is available 24 hours a day,
365 days a year.
Calling for Assistance
When calling Roadside Assistance,
have the following information
ready:
.Your name, home address, and
home telephone number.
.Telephone number of your
location.
.Location of the vehicle

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-5
FlexFuelE85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-65
Floor Console Storage . . . . . . . . . . 4-3
Floor Mats . . . . . . . . . . . . . . . . . . .10-105
Fluid AutomaticTransmission . . . . . . . 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 FuelContainer . . . . . . . . . . . . . . . . . . . 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 CompartmentFuse Block . . . . . . . . . . . . . . . . 10-41
Instrument Panel
Fuse Block . . . . . . . . . 10-45, 10-48G
Garage Door Opener . . . . . . . . . . 5-49Programming . . . . . . . . . . . . . . . . . 5-49
Gauges Engine CoolantTemperature . . . . . . . . . . . . . . . . 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