towing 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 (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 ManualM
Jump 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 (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-3
1.Instrument Panel Illumination
Control on page 6-6.
2. Integrated Trailer Brake Control (ITBC) System (If Equipped).
See Towing Equipment on
page 9-78.
3. Exterior Lamp Controls on
page 6-1.
Fog Lamps on page 6-5 (If
Equipped).
4. Air Vents on page 8-4.
5. Turn Signal Lever. See Turn and
Lane-Change Signals on
page 6-4.
Windshield Wiper/Washer on
page 5-3.
6. Favorite Switches (Out of View). See Steering Wheel Controls on
page 5-2.
Volume Switches (Out of View).
See Steering Wheel Controls on
page 5-2.
7. Instrument Cluster on page 5-9. 8.
Hazard Warning Flashers on
page 6-4
9. Shift Lever. See Automatic
Transmission on page 9-33.
Tow/Haul Selector Button (If
Equipped). See Tow/Haul Mode
on page 9-39.
Range Selection Mode (If
Equipped). See Manual Mode on
page 9-36.
10. Light Sensor. See Automatic
Headlamp System on
page 6-3.
11. Infotainment on page 7-1.
12. Electronic Transfer Case Control (If Equipped). See
Four-Wheel Drive on
page 9-40.
13. Parking Brake on page 9-47.
14. Data Link Connector (DLC) (Out of View). See Malfunction
Indicator Lamp on page 5-18. 15.
Cruise Control on page 9-52.
Forward Collision Alert (FCA)
System on page 9-59 (If
Equipped).
16. Steering Wheel Adjustment on
page 5-2 (Out of View).
17. Horn on page 5-3.
18. Hood Release. See Hood on
page 10-4.
19. Steering Wheel Controls on
page 5-2 (If Equipped).
Driver Information Center (DIC)
Controls. See Driver
Information Center (DIC) on
page 5-27.
20. Heated and Cooled Front
Seats on page 3-7 (If
Equipped).
21. Dual Automatic Climate Control
System on page 8-1.

Black plate (16,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
1-16 In Brief
Automatic Transfer Case
This transfer case knob is to the left
of the steering column.
The different drive options that may
be available are described following.
2
m(Two-Wheel Drive High):This
setting is used for driving in most
street and highway situations.
AUTO (Automatic Four-Wheel
Drive): This setting is ideal for use
when road surface traction
conditions are variable. Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud or gravel. In
AUTO mode only the rear wheels
will hold the vehicle from sliding
when parked. If parking on a steep
grade, use 4
mto keep all four
wheels engaged.
4
m(Four-Wheel Drive High): Use
this setting when extra traction is
needed, such as on snowy or icy
roads or in most off-road situations.
N (Neutral): Shift to this setting
only when towing the vehicle. See
Recreational Vehicle Towing on
page 10-91 orTrailer Towing on
page 9-71.
4
n(Four-Wheel Drive Low): This
setting sends maximum power to all
four wheels. Choose Four-Wheel
Drive Low when driving in deep
sand, mud, or snow, and while
climbing or descending steep hills.
See Four-Wheel Drive on
page 9-40.
Vehicle Features
Infotainment System
See the infotainment manual for
information on the radio, audio
players, phone, navigation system,
and voice or speech recognition.
It also includes information on
settings.
Steering Wheel Controls
The infotainment system can be
operated by using the steering
wheel controls. See "Steering
Wheel Controls" in the infotainment
manual.

Black plate (14,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-14 Keys, Doors, and Windows
Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
Trailer-Tow Mirrors
If equipped, adjust trailer-tow
mirrors for a clear view of the area
behind you. Manually pull out the
mirror head to extend it for better
visibility when towing a trailer.
The lower portion of the mirror is
convex. A convex mirror's surface is
curved to see more from the driver
seat. The convex mirror can be
adjusted manually to the driver
preferred position for better vision. The mirror may have a turn signal
arrow that flashes in the direction of
the turn or lane change.
If equipped, the mirror housing may
have auxiliary cargo and clearance
lamps. See
Cargo Lamp on
page 6-6 andExterior Lamp
Controls on page 6-1.
Power Mirrors
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.

Black plate (17,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-17
Turn Signal Indicator
If equipped, indicator lights on the
mirror flash in the direction of the
turn or lane change.
Heated Mirrors
If equipped with heated mirrors:
1(Rear Window Defogger):
Press to heat the mirrors. If the
vehicle has towing mirrors, only the
upper glass of the mirror is heated.
The lower convex part of the towing
mirrors is not heated.
See “Rear Window Defogger” under
Dual Automatic Climate Control
System on page 8-1.
Automatic Dimming
Mirror
If equipped, the driver outside mirror
automatically adjusts for the glare of
the headlamps from behind. This
feature comes on when the vehicle
is started.
Blind Spot Mirrors
If equipped, there is a small convex
mirror built into the upper and outer
corner of the driver outside rearview
mirror. It can show objects that may
be in the vehicle's blind zone.
Driving with the Blind Spot
Mirror
Actual Mirror View

Black plate (28,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
3-28 Seats and Restraints
Additional Factors Affecting
System Operation
Safety belts help keep the
passenger in position on the seat
during vehicle maneuvers and
braking, which helps the passenger
sensing system maintain the
passenger airbag status. See
“Safety Belts”and“Child Restraints”
in the Index for additional
information about the importance of
proper restraint use.
A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such as
seat covers, seat heaters, and seat
massagers can affect how well the
passenger sensing system
operates. We recommend that you
not use seat covers or other
aftermarket equipment except when
approved by GM for your specific
vehicle. See Adding Equipment to
the Airbag-Equipped Vehicle on
page 3-28 for more information
about modifications that can affect
how the system operates. The on indicator may be lit if an
object, such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device, is put on
an unoccupied seat. If this is not
desired, remove the object from
the seat.
{Warning
Stowing of articles under the
passenger seat or between the
passenger seat cushion and
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system.
To purchase a service manual, see
Service Publications Ordering
Information on page 13-11.
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly. The

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 (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-21
Brake System Warning
Light
The vehicle brake system consists
of two hydraulic circuits. If one
circuit is not working, the remaining
circuit can still work to stop the
vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on, there
is a brake problem. Have the brake
system inspected right away.
MetricEnglish
This light should come on briefly
when the engine is started. If it does
not come on then, have it fixed so it
will be ready to warn if there is a
problem. When the ignition is on, the brake
system warning light also comes on
when the parking brake is set. The
light stays on if the parking brake
does not fully release. If it stays on
after the parking brake is fully
released, it means the vehicle has a
brake problem.
If the light comes on while driving,
pull off the road and stop carefully.
The pedal might be harder to push,
or the pedal can go closer to the
floor. It may take longer to stop.
If the light is still on, have the
vehicle towed for service. See
Towing the Vehicle on page 10-91.
{Warning
The brake system might not be
working properly if the brake
system warning light is on.
Driving with the brake system
warning light on can lead to a
crash. If the light is still on after
the vehicle has been pulled off
(Continued)
Warning (Continued)
the road and carefully stopped,
have the vehicle towed for
service.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine is started.
If the light does not come on, have it
fixed so it will be ready to warn if
there is a problem.
If the light comes on while driving,
stop as soon as it is safely possible
and turn off the vehicle. Then start
the engine again to reset the
system. If the ABS light stays on,
or comes on again while driving, the

Black plate (32,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-32 Instruments and Controls
SERVICE BATTERY
CHARGING SYSTEM
On some vehicles, this message
displays if there is a problem with
the battery charging system. Under
certain conditions, the charging
system light may also turn on in the
instrument cluster. SeeCharging
System Light on page 5-18. Driving
with this problem could drain the
battery. Turn off all unnecessary
accessories. Have the electrical
system checked as soon as
possible. See your dealer.
TRANSPORT MODE ON
This message is displayed when the
vehicle is in transport mode. Some
features can be disabled while in
this mode, including Remote
Keyless Entry (RKE), remote start,
and the vehicle alarm system. Take
the vehicle to your dealer for service
to turn transport mode off.
Brake System Messages
BRAKE FLUID LOW
This message is displayed when the
brake fluid level is low. See Brake
Fluid on page 10-27.
SERVICE BRAKE ASSIST
This message may be displayed
when there is a problem with the
brake boost assist system. When
this message is displayed, the brake
boost assist motor might be heard
operating and you might notice
pulsation in the brake pedal. This is
normal under these conditions. Take
the vehicle to your dealer for
service.
SERVICE TRAILER BRAKE
SYSTEM
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays and a chime
may sound when there is a problem
with the ITBC system. When this message displays, power
is no longer available to the trailer
brakes.
As soon as it is safe to do so,
carefully pull your vehicle over to
the side of the road and turn the
ignition off. Check the wiring
connection to the trailer and turn the
ignition back on. If this message still
displays, either your vehicle or the
trailer needs service. See your
dealer.
See
“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9-78 for more
information.
Compass Messages
Dashes may be displayed if the
vehicle temporarily loses
communication with the Global
Positioning System (GPS).