2015 GMC SIERRA DENALI check engine

Black plate (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-3
Maintenance
Schedule Owner Checks and Services At Each Fuel Stop .
Check the engine oil level. See
Engine Oil on page 10-8 .
Once a Month .
Check the tire inflation
pressures. See Tire Pressure on
page 10-59 ..
Inspect the tires for wear. See
Tire Inspection on page 10-65 ..
Check the windshield washer
fluid level. See Washer Fluid on
page 10-25 .
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system may not
indicate the need for vehicle service for up to a year. The engine oil and
filter must be changed at least once
a year and the oil life system must
be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
See Engine Oil Life System on
page 10-11 .
Passenger Compartment Air
Filter The passenger compartment air
filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
Inspect the passenger compartment
air filter every 36 000 km/
22,500 miles or two years,
whichever comes first. Replace if
necessary. 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.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi Rotate the tires, if recommended for
the vehicle, and perform the
following services. See Tire
Rotation on page 10-65 . .
Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil on page 10-8 and Engine Oil
Life System on page 10-11 . .
Check engine coolant level. See
Engine Coolant on page 10-18 . .
Check windshield washer fluid
level. See Washer Fluid on
page 10-25 .

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. See Exterior
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 (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-5Maintenance Schedule
Additional Required
Services - Normal
12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 miRotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @Replace passenger compartment air filter. (1)
@ @ @ @ @ @Inspect evaporative control system. (2)
@ @ @Replace engine air cleaner filter. (3)
@ @ @Replace spark plugs. Inspect spark plug wires.
@Drain and fill engine cooling system. (4)
@Visually inspect accessory drive belts. (5)
@Replace brake fluid. (6)
@ @ @

Black plate (7,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-7Maintenance Schedule
Additional Required
Services - Severe
12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 miRotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @Replace passenger compartment air filter. (1)
@ @ @ @ @ @Inspect evaporative control system. (2)
@ @ @Replace engine air cleaner filter. (3)
@ @ @Replace spark plugs. Inspect spark plug wires.
@Change automatic transmission fluid and filter.
@ @ @Change transfer case fluid, if equipped with
4WD. (4)
@ @ @Extreme Service: Change transfer case fluid,
if equipped with 4WD. (4, 5)
@ @ @ @ @ @Drain and fill engine cooling system. (6)
@Visually inspect accessory drive belts. (7)
@Replace brake fluid. (8)
@ @ @

Black plate (9,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Service and Maintenance 11-9
Additional
Maintenance and Care Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional
maintenance services may be
required.
It is recommended that your dealer
perform these services — their
trained dealer technicians know
your vehicle best. Your dealer can
also perform a thorough
assessment with a multi-point
inspection to recommend when your
vehicle may need attention.
The following list is intended to
explain the services and conditions
to look for that may indicate
services are required. Battery
The battery supplies power to start
the engine and operate any
additional electrical accessories. .
To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power. .
Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts .
Belts may need replacing if they
squeak or show signs of
cracking or splitting. .
Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary. Brakes
Brakes stop the vehicle and are
crucial to safe driving. .
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping. .
Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle ’ s systems
and components. See
Recommended Fluids and
Lubricants on page 11-12 for GM
approved fluids. .
Engine oil and windshield
washer fluid levels should be
checked at every fuel fill. .
Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.

Black plate (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Technical Data 12-3Application Capacities
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 Y 140 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 SpecificationsEngine VIN Code Spark Plug Gap
5.3L V8 (L83) C 0.95 – 1.10 mm (0.037 –
0.043 in)
6.0L V8 (L96) G 0.95 – 1.10 mm (0.037 –
0.043 in)
6.2L V8 (L86) J 0.95 – 1.10 mm (0.037 –
0.043 in)

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
14-6 OnStar
Vehicle Diagnostics OnStar Vehicle Diagnostics can
perform a vehicle check every
month. It will check the engine,
transmission, antilock brakes, and
other major vehicle systems. It also
checks the tire pressures, if the
vehicle is equipped with the Tire
Pressure Monitoring System. If an
On-Demand Diagnostics check is
needed, press
Q , and an Advisor
can run a check.
OnStar Additional
Information Transferring Service Press
Q to request account transfer
eligibility information. The Advisor
can assist in canceling or removing
account information.
Selling/Transferring the
Vehicle Call 1-888-4-ONSTAR immediately
to terminate your OnStar services if
the vehicle is disposed of, sold,
transferred, or if the lease ends.
Reactivation for Subsequent
Owners
Press
Q and follow the prompts to
speak to an Advisor as soon as
possible. The Advisor will update
vehicle records and explain the
OnStar service options available. How OnStar Service Works Automatic Crash Response,
Emergency Services, Crisis Assist,
Stolen Vehicle Assistance, Vehicle
Diagnostics, Remote Door Unlock,
Roadside Assistance, Turn-by-Turn
Navigation, and Hands-Free Calling
are available on most vehicles. Not
all OnStar services are available
everywhere or on all vehicles. For
more information, a full description
of OnStar services, system
limitations, and OnStar terms and
conditions: .
Call 1-888-4-ONSTAR
(1-888-466-7827). .
See www.onstar.com (U.S.). .
See www.onstar.ca (Canada). .
Call TTY 1-877-248-2080. .
Press
Q to speak with an
Advisor.
OnStar services cannot work unless
the vehicle is in a place where
OnStar has an agreement with a
wireless service provider for service

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