tires GMC SIERRA 2015 Owner's Manual

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
2015 GMC Sierra Denali Owner ManualM
In Brief. . . . . . . . . . . . . . . . . . . . . . . . 1-1
Instrument Panel . . . . . . . . . . . . . . 1-2
Initial Drive Information . . . . . . . . 1-4
Vehicle Features . . . . . . . . . . . . . 1-16
Performance and Maintenance . . . . . . . . . . . . . . . . 1-20
Keys, Doors, and Windows . . . . . . . . . . . . . . . . . . . . 2-1
Keys and Locks . . . . . . . . . . . . . . . 2-1
Doors . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Vehicle Security . . . . . . . . . . . . . . 2-11
Exterior Mirrors . . . . . . . . . . . . . . . 2-14
Interior Mirrors . . . . . . . . . . . . . . . . 2-19
Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Roof . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Seats and Restraints . . . . . . . . . 3-1
Head Restraints . . . . . . . . . . . . . . . 3-2
Front Seats . . . . . . . . . . . . . . . . . . . . 3-3
Rear Seats . . . . . . . . . . . . . . . . . . . . 3-9
Safety Belts . . . . . . . . . . . . . . . . . . 3-10
Airbag System . . . . . . . . . . . . . . . . 3-17
Child Restraints . . . . . . . . . . . . . . 3-30 Storage
. . . . . . . . . . . . . . . . . . . . . . . 4-1
Storage Compartments . . . . . . . . 4-1
Additional Storage Features . . . 4-3
Instruments and Controls . . . . 5-1
Controls . . . . . . . . . . . . . . . . . . . . . . . 5-2
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . 5-8
Information Displays . . . . . . . . . . 5-27
Vehicle Messages . . . . . . . . . . . . 5-31
Vehicle Personalization . . . . . . . 5-42
Universal Remote System . . . . 5-49
Lighting . . . . . . . . . . . . . . . . . . . . . . . 6-1
Exterior Lighting . . . . . . . . . . . . . . . 6-1
Interior Lighting . . . . . . . . . . . . . . . . 6-6
Lighting Features . . . . . . . . . . . . . . 6-8
Infotainment System . . . . . . . . . 7-1
Introduction . . . . . . . . . . . . . . . . . . . . 7-1 Climate Controls
. . . . . . . . . . . . . 8-1
Climate Control Systems . . . . . . 8-1
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 8-4
Maintenance . . . . . . . . . . . . . . . . . . . 8-5
Driving and Operating . . . . . . . . 9-1
Driving Information . . . . . . . . . . . . . 9-2
Starting and Operating . . . . . . . 9-23
Engine Exhaust . . . . . . . . . . . . . . 9-32
Automatic Transmission . . . . . . 9-33
Drive Systems . . . . . . . . . . . . . . . . 9-40
Brakes . . . . . . . . . . . . . . . . . . . . . . . 9-46
Ride Control Systems . . . . . . . . 9-49
Cruise Control . . . . . . . . . . . . . . . . 9-52
Driver Assistance Systems . . . 9-55
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Trailer Towing . . . . . . . . . . . . . . . . 9-68
Conversions and Add-Ons . . . 9-88
Vehicle Care . . . . . . . . . . . . . . . . . 10-1
General Information . . . . . . . . . . 10-2
Vehicle Checks . . . . . . . . . . . . . . . 10-3
Headlamp Aiming . . . . . . . . . . . 10-36
Bulb Replacement . . . . . . . . . . 10-36
Electrical System . . . . . . . . . . . . 10-40
Wheels and Tires . . . . . . . . . . . 10-50

Black plate (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-21
The low tire pressure warning light
alerts to a significant loss in
pressure of one of the vehicle's
tires. If the warning light comes on,
stop as soon as possible and inflate
the tires to the recommended
pressure shown on the Tire and
Loading Information label. See
Vehicle Load Limits on page 9-15.
The warning light will remain on until
the tire pressure is corrected.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
may be an early indicator that the
tire pressures are getting low and
the tires need to be inflated to the
proper pressure.
The TPMS does not replace normal
monthly tire maintenance. Maintain
the correct tire pressures.
SeeTire Pressure Monitor System
on page 10-61.Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays a DIC message when
it is necessary to change the engine
oil and filter. The oil life system
should be reset to 100% only
following an oil change.
Resetting the Oil Life System
1. Display OIL LIFE REMAINING
on the DIC. See Driver
Information Center (DIC) on
page 5-27.
2. Press and hold
Vfor several
seconds. The oil life will change
to 100%.
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.
See Engine Oil Life System on
page 10-11.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or
ethanol fuel containing up to 85%
ethanol (E85). See E85 or FlexFuel
on page 9-65. For all other vehicles,
use only the unleaded gasoline
described under Fuel on page 9-63.
Driving for Better Fuel
Economy
Driving habits can affect fuel
mileage. Here are some driving tips
to get the best fuel economy
possible.
.Avoid fast starts and accelerate
smoothly.
.Brake gradually and avoid
abrupt stops.

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):
1-888-889-2438Canada: 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 3-29
operation 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 pador 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 (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-19
{Caution
If the vehicle is continually driven
with this light on, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
{Caution
Modifications made to the engine,
transmission, exhaust, intake,
or fuel system of the vehicle or
the replacement of the original
tires with other than those of the
same Tire Performance Criteria
(TPC) can affect the vehicle's
emission controls and can cause
this light to come on.
Modifications to these systems(Continued)
Caution (Continued)
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test. See
Accessories and Modifications on
page 10-3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.
To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled as
soon as it is possible.
If the light continues to flash, find a
safe place to stop and park the
vehicle. Turn the vehicle off, wait at
least 10 seconds, and restart the
engine. If the light is still flashing,
follow the previous steps and see
your dealer for service as soon as
possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.
The following may correct an
emission control system
malfunction:
.Check that the fuel cap is fully
installed. See Filling the Tank on
page 9-66. The diagnostic
system can determine if the fuel
cap has been left off or
improperly installed. A loose or
missing fuel cap allows fuel to
evaporate into the atmosphere.

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. SeeTire 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
{Caution
Lack 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 (30,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-30 Instruments and Controls
Tire Pressure:Shows the
approximate pressures of all four
tires. Tire pressure is displayed in
either kilopascal (kPa) or in pounds
per square inch (psi). If the pressure
is low, the value for that tire is
shown in amber. See Tire Pressure
Monitor System on page 10-61 and
Tire Pressure Monitor Operation on
page 10-62.
Best Fuel Economy: Displays
average fuel economy, the best fuel
economy over the selected
distance, and a bar graph showing
instantaneous fuel economy.
Press
pto change the selected
distance. Press and hold
Vwhile
this display is active to reset the
best fuel economy and average fuel
economy. This display can also be
reset by selecting reset in the menu.
Top Consumers: Shows a list of
the features that are currently
impacting the fuel economy, in order
from highest to lowest. If a feature is
turned off, it will be removed from
the list. Economy Trend:
Shows history of
the Average Fuel Economy from the
last 50 km (30 mi). Each bar
represents about 5 km (3 mi) of
driving. During driving the bars will
shift to always reflect the most
recent distance on the right side.
Press and hold
Vto clear the graph
or press
pto reset through
the menu.
ECO Index: The bar graph
provides feedback on the efficiency
of current driving behavior. The
graph shows a value that is based
on current fuel consumption
compared to what is expected from
the vehicle with good and bad
driving habits. It also shows if the
Active Fuel Management is active
and in V4 mode, or inactive and in
V8 mode. See Active Fuel
Management
®on page 9-32.
Engine Hours: Shows the total
number of hours the engine has run.
This display also shows the engine
idle hours. Trailer Brake:
On vehicles with the
Integrated Trailer Brake Control
(ITBC) system, the trailer brake
display appears in the DIC.
TRAILER GAIN shows the trailer
gain setting. This setting can be
adjusted from 0.0 to 10.0 with either
a trailer connected or disconnected.
OUTPUT shows the power output to
the trailer any time a trailer with
electric brakes is connected. Output
is displayed as a bar graph. Dashes
may appear in the OUTPUT display.
Speed Signs: Shows sign
information, which comes from a
roadway database in the onboard
navigation.
Following Distance: Used to
select the alert timing for the
Forward Collision Alert (FCA). See
Forward Collision Alert (FCA)
System on page 9-59.
Blank Page: Shows no
information.

Black plate (39,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-39
If the warning comes on and stays
on, there may be a problem with the
TPMS. See your dealer.
TIRE LEARNING ACTIVE
If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays when the system
is relearning the tire positions on
your vehicle. The tire positions must
be relearned after rotating the tires
or after replacing a tire or sensor.
SeeTire Inspection on page 10-65,
Tire Rotation on page 10-65, Tire
Pressure Monitor System on
page 10-61, and Tire Pressure on
page 10-59.
TIRE PRESSURE LOW ADD
AIR TO TIRE
If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires is low. This message
also displays with a vehicle picture
to indicate the location of the low
tire. The low tire pressure warning
light will also come on. See Tire
Pressure Light on page 5-25. You
can receive more than one tire
pressure message at a time. If a tire
pressure message appears on the
DIC, stop as soon as you can. Have
the tire pressures checked and set
to those shown on the Tire and
Loading Information label. See Tires
on page 10-50, Vehicle Load Limits
on page 9-15, and Tire Pressure on
page 10-59. The DIC also shows
the tire pressure values. See Driver
Information Center (DIC) on
page 5-27.
Transmission Messages
4WD OFF
If equipped with four-wheel drive,
this message displays when the
four-wheel-drive system is
temporarily disabled due to an
overheated condition. The vehicle
will run in two-wheel drive when this
message is present. Once the
four-wheel-drive system cools down,
the message turns off and the
four-wheel-drive system returns to
normal operation.
4WD SHIFT IN PROGRESS
This message will display while the
four-wheel-drive system is shifting.
FOR 4WD LOW SHIFT TO
NEUTRAL
If a four-wheel drive shift into 4nis
requested, and the vehicle speed is
correct, but the transmission is not
in N (Neutral), this message will
display until the transmission is
shifted to N (Neutral).

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-5
.Wait until the vehicle is out of
the curve before accelerating
gently into the straightaway.
Steering in Emergencies
.There are some situations when
steering around a problem may
be more effective than braking.
.Holding both sides of the
steering wheel allows you to turn
180 degrees without removing
a hand.
.Antilock Brake System (ABS)
allows steering while braking.
Off-Road Recovery
The vehicle's right wheels can drop
off the edge of a road onto the
shoulder while driving. Follow
these tips:
1. Ease off the accelerator andthen, if there is nothing in the
way, steer the vehicle so that it
straddles the edge of the
pavement.
2. Turn the steering wheel about one-eighth of a turn, until the
right front tire contacts the
pavement edge. 3. Turn the steering wheel to go
straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three
control systems:
.Braking Skid —wheels are not
rolling.
.Steering or Cornering Skid —
too much speed or steering in a
curve causes tires to slip and
lose cornering force.
.Acceleration Skid —too much
throttle causes the driving
wheels to spin.
Defensive drivers avoid most skids
by taking reasonable care suited to
existing conditions, and by not
overdriving those conditions. But
skids are always possible.

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-6 Driving and Operating
If the vehicle starts to slide, follow
these suggestions:
.Ease your foot off the
accelerator pedal and steer the
way you want the vehicle to go.
The vehicle may straighten out.
Be ready for a second skid if it
occurs.
.Slow down and adjust your
driving according to weather
conditions. Stopping distance
can be longer and vehicle
control can be affected when
traction is reduced by water,
snow, ice, gravel, or other
material on the road. Learn to
recognize warning clues—such
as enough water, ice, or packed
snow on the road to make a
mirrored surface —and slow
down when you have any doubt.
.Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle speed
by shifting to a lower gear. Any
sudden changes could cause
the tires to slide. Remember: Antilock brakes help
avoid only the braking skid.
Off-Road Driving
Four-wheel-drive vehicles can be
used for off-road driving. Vehicles
without four-wheel drive and
vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR)
tires must not be driven off-road
except on a level, solid surface. For
contact information about the
original equipment tires, see the
warranty manual.
One of the best ways for successful
off-road driving is to control the
speed.
{Warning
When driving off-road, bouncing
and quick changes in direction
can easily throw you out of
position. This could cause you to
lose control and crash. You and
your passengers should always
wear safety belts.
Before Driving Off-Road
.Have all necessary maintenance
and service work completed.
.Fuel the vehicle, fill fluid levels,
and check inflation pressure in
all tires, including the spare,
if equipped.
.Read all the information about
four-wheel-drive vehicles in this
manual.
.Remove any underbody air
deflector, if equipped. Re-attach
the air deflector after off-road
driving.
.See
Hill Descent Control (HDC)
on page 9-51
.Know the local laws that apply to
off-road driving.
To gain more ground clearance if
needed, it may be necessary to
remove the front fascia lower air
dam. However, driving without the
air dam reduces fuel economy.