service schedule GMC SIERRA DENALI 2015 Owners Manual

Black plate (2,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
2015 GMC Sierra Denali Owner Manual MJump Starting . . . . . . . . . . . . . . . 10-87
Towing the Vehicle . . . . . . . . . . 10-91
Appearance Care . . . . . . . . . . . 10-96
Service and Maintenance . . . 11-1
General Information . . . . . . . . . . 11-1
Maintenance Schedule . . . . . . . 11-3
Special Application
Services . . . . . . . . . . . . . . . . . . . . 11-8
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . 11-9
Recommended Fluids,
Lubricants, and Parts . . . . . . 11-12
Maintenance Records . . . . . . . 11-16
Technical Data . . . . . . . . . . . . . . . 12-1
Vehicle Identification . . . . . . . . . 12-1
Vehicle Data . . . . . . . . . . . . . . . . . . 12-2
Customer Information . . . . . . . 13-1
Customer Information . . . . . . . . 13-1
Reporting Safety Defects . . . . 13-13
Vehicle Data Recording and
Privacy . . . . . . . . . . . . . . . . . . . . 13-14 OnStar . . . . . . . . . . . . . . . . . . . . . . . 14-1
OnStar Overview . . . . . . . . . . . . . 14-1
OnStar Services . . . . . . . . . . . . . . 14-2
OnStar Additional
Information . . . . . . . . . . . . . . . . . . 14-6
Index . . . . . . . . . . . . . . . . . . . . . i-1

Black plate (22,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
1-22 In Brief .
Avoid idling the engine for long
periods of time. .
When road and weather
conditions are appropriate, use
cruise control. .
Always follow posted speed
limits or drive more slowly when
conditions require. .
Keep vehicle tires properly
inflated. .
Combine several trips into a
single trip. .
Replace the vehicle's tires with
the same TPC Spec number
molded into the tire's sidewall
near the size. .
Follow recommended scheduled
maintenance.
Roadside Assistance
Program U.S.: 1-888-881-3302
TTY Users (U.S. Only):
1-888-889-2438 Canada: 1-800-268-6800
New GMC owners are automatically
enrolled in the Roadside Assistance
Program.
See Roadside Assistance Program
on page 13-5 .
OnStar ®
This vehicle may be equipped with a
comprehensive, in-vehicle system
that can connect to a live OnStar
Advisor for Emergency, Security,
Navigation, Connection, and
Diagnostic Services. OnStar
services may require a paid
subscription. See OnStar Overview
on page 14-1 .

Black plate (29,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Seats and Restraints 3-29operation of the airbag system can
also be affected by changing or
moving any parts of the front seats,
safety belts, the airbag sensing and
diagnostic module, steering wheel,
instrument panel, roof-rail airbag
modules, ceiling headliner or pillar
garnish trim, overhead console,
front sensors, side impact sensors,
or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
In addition, the vehicle may have a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with
GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See Passenger Sensing System on
page 3-24 .
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels on page 10-70 for
additional important information.
If a snow plow is added to the
vehicle, the airbags should still work
properly. The airbag systems were
designed to work properly under a
wide range of conditions, including
snow plowing with vehicles that
have the optional snow plow prep
package (RPO VYU). Do not
change or defeat the snow plow's
“ tripping mechanism. ” If you do, it
can damage the snow plow and the
vehicle, and may cause an airbag
deployment. If you have to modify your vehicle
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other
reason, call Customer Assistance.
See Customer Assistance Offices
on page 13-3 .
Airbag System Check The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light on
page 5-16 .
{ Caution
If an airbag covering is damaged,
opened, or broken, the airbag
may not work properly. Do not
open or break the airbag
(Continued)

Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-13
English, Standard Theme Shown
The engine oil pressure gauge
shows the engine oil pressure
in kPa (kilopascals) or psi (pounds
per square inch) when the engine is
running.
Oil pressure can vary with engine
speed, outside temperature and oil
viscosity.
A reading outside the normal
operating range can be caused by a
dangerously low oil level or some
other problem causing low oil
pressure. Check the vehicle's oil as
soon as possible. See “ OIL PRESSURE LOW STOP
ENGINE ” under Engine Oil
Messages on page 5-34 and Engine
Oil on page 10-8 .
{ CautionLack of proper engine oil
maintenance can damage the
engine. Driving with the engine
oil low can also damage the
engine. The repairs would not be
covered by the vehicle warranty.
Check the oil level as soon as
possible. Add oil if required, but if
the oil level is within the operating
range and the oil pressure is still
low, have the vehicle serviced.
Always follow the maintenance
schedule for changing engine oil.
If the vehicle has a diesel engine,
see the Duramax diesel
supplement. Engine Coolant
Temperature Gauge
Metric, Standard Theme Shown

Black plate (25,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-25
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information
about tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of
the tires are significantly
underinflated.
A Driver Information Center (DIC)
tire pressure message may also
display. See Tire Messages on
page 5-38 . Stop as soon as
possible, and inflate the tires to the
pressure value shown on the Tire
and Loading Information label. See
Tire Pressure on page 10-59 . When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light
will come on at every ignition cycle.
See Tire Pressure Monitor
Operation on page 10-62 .
Engine Oil Pressure Light
{ CautionLack of proper engine oil
maintenance can damage the
engine. Driving with the engine
oil low can also damage the
engine. The repairs would not be
covered by the vehicle warranty.
Check the oil level as soon as
possible. Add oil if required, but if
the oil level is within the operating
range and the oil pressure is still
low, have the vehicle serviced.
Always follow the maintenance
schedule for changing engine oil. This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced
by your dealer.
If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle
could be low on oil and might have
some other system problem. See
your dealer.
Low Fuel Warning Light

Black plate (34,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-34 Instruments and Controls
Engine Oil Messages CHANGE ENGINE OIL SOON This message displays when the
engine oil needs to be changed.
When you change the engine oil, be
sure to reset the CHANGE ENGINE
OIL SOON message. See Engine
Oil Life System on page 10-11 for
information on how to reset the
message. See Engine Oil on
page 10-8 and Maintenance
Schedule on page 11-3 .
ENGINE OIL LOW ADD OIL On some vehicles, this message
displays when the engine oil level
may be too low. Check the oil level
before filling to the recommended
level. If the oil is not low and this
message remains on, take the
vehicle to your dealer for service.
See Engine Oil on page 10-8 . ENGINE OIL HOT IDLE
ENGINE This message displays when the
engine oil becomes hotter than the
normal operating temperature. Stop
and allow the vehicle to idle until it
cools down. See Engine Coolant
Temperature Gauge on page 5-13 .
OIL PRESSURE LOW STOP
ENGINE This message displays if low oil
pressure levels occur. Stop the
vehicle as soon as safely possible
and do not operate it until the cause
of the low oil pressure has been
corrected. Check the oil as soon as
possible and have the vehicle
serviced by your dealer. See Engine
Oil on page 10-8 .
Engine Power Messages ENGINE POWER IS REDUCED
This message displays and a chime
may sound when the cooling system
temperature gets too hot and the engine further enters the engine
coolant protection mode. See
Engine Overheating on page 10-21
for more information.
This message also displays when
the vehicle's engine power is
reduced. Reduced engine power
can affect the vehicle's ability to
accelerate. If this message is on,
but there is no reduction in
performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
at a reduced speed while this
message is on, but acceleration and
speed may be reduced. Anytime
this message stays on, the vehicle
should be taken to your dealer for
service as soon as possible.

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-11suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See the Maintenance
Schedule on page 11-3 .
Driving on Wet Roads Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep ‐ standing or flowing water.
{ Warning
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
(Continued) Warning (Continued) After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is
wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road. There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips Besides slowing down, other wet
weather driving tips include: .
Allow extra following distance. .
Pass with caution. .
Keep windshield wiping
equipment in good shape. .
Keep the windshield washer fluid
reservoir filled. .
Have good tires with proper
tread depth. See Tires on
page 10-50 . .
Turn off cruise control.
Hill and Mountain Roads Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include: .
Keep the vehicle serviced and in
good shape.

Black plate (71,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-717. Stop and have someone pick up
and store the chocks.
Maintenance when Trailer
Towing The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3 . Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
If the vehicle is bi-fuel, see the
bi-fuel supplement. Do not tow a trailer during break-in.
See New Vehicle Break-In on
page 9-23 for more information.
{ WarningThe driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well or even at all. The driver and
passengers could be seriously
injured. The vehicle may also be
damaged; the resulting repairs
would not be covered by the
vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle. { CautionPulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
See Vehicle Load Limits on
page 9-15 for more information
about the vehicle's maximum load
capacity.
To identify the trailering capacity of
the vehicle, read the information in
“ Weight of the Trailer ” later in this
section.

Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-12 Vehicle Care 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.
If the vehicle has a CHANGE
ENGINE OIL SOON message and it
comes back on when the vehicle is
started and/or the OIL LIFE
REMAINING is near 0%, the engine
oil life system has not been reset.
Repeat the procedure. Automatic Transmission
Fluid (6 Speed
Transmission) When to Check and Change
Automatic Transmission Fluid It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer service department and have
it repaired before driving the vehicle
further.
{ Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
(Continued) Caution (Continued) not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-12 .
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-3 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-12 .
How to Check Automatic
Transmission Fluid
{ Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
(Continued)

Black plate (15,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-155. Safe operating level is within the
HOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level is
low, add only enough fluid to
bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. If the fluid level is in the
acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer. Automatic Transmission
Fluid (8 Speed
Transmission) When to Check and Change
Automatic Transmission Fluid It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. This vehicle is not
equipped with a transmission fluid
level dipstick. There is a special
procedure for checking and
changing the transmission fluid in
these vehicles. Because this
procedure is difficult, this should be
done at the dealer. Contact the
dealer for additional information or
the procedure can be found in the
service manual. See Service
Publications Ordering Information
on page 13-11 .{ CautionUse of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-12 .
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-3 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-12 .
Engine Air Cleaner/Filter If the vehicle has a diesel engine,
see “ Pickup Models ” under “ Engine
Air Cleaner/Filter ” in the Duramax
diesel supplement for the correct
inspection and replacement
procedures.