
Black plate (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
8-4 Climate Controls Caution (Continued)not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Heated Mirror: If equipped with
heated outside rearview mirrors, the
mirrors heat to help clear fog or frost
from the surface of the mirror when
the rear window defog button is
pressed. See Heated Mirrors on
page 2-17 .
Sensors The solar sensor, located in the
defrost grille in the middle of the
instrument panel, monitors the solar
heat. Do not cover the solar sensor
or the system will not work properly.
There is also an exterior
temperature sensor behind the front
grille. This sensor reads the outside
air temperature and helps maintain
the temperature inside the vehicle.
Any cover on the front of the vehicle
including a snow plow, could cause
a false reading in the displayed
temperature.
The climate control system uses the
information from these sensors to
maintain comfort settings by
adjusting the outlet temperature, fan
speed, and the air delivery mode.
The system may also supply cooler
air to the side of the vehicle facing
the sun. The recirculation mode will
also be used as needed to maintain
cool outlet temperatures. Air Vents Use the air vents in the center and
on the side of the instrument panel
to direct airflow. Use the
thumbwheels near the air vents to
open or close off the airflow.
Air vents blow warm air on the side
windows in cold weather. If Floor,
Defog, or Defrost modes are
selected, a small amount of air will
come from the vents close to the
window. If the airflow is shut off
using the thumbwheels, warm air
will be directed to the other
instrument panel vents. This is
normal operation.
Use the thumbwheels to turn vent
airflow on or off based on the mode
selected.
Operation Tips .
Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.

Black plate (61,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-61Selecting the Alert Timing
The FCA control is on the steering
wheel. Press
[ to set the FCA
timing to Far, Medium, Near, or Off.
The first button press shows the
current setting on the DIC.
Additional button presses will
change this setting. The chosen
setting will remain until it is changed
and will affect the timing of both the
Collision Alert and the Tailgating
Alert features. The timing of both
alerts will vary based on vehicle
speed. The faster the vehicle speed,
the farther away the alert will occur. Consider traffic and weather
conditions when selecting the alert
timing. The range of selectable alert
timing may not be appropriate for all
drivers and driving conditions.
Unnecessary Alerts FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the rearview mirror, and cleaning the
front of the vehicle where radar
sensors are located, may correct
the issue. Lane Departure
Warning (LDW) If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide an alert if
the vehicle is crossing a lane
marking without using a turn signal
in that direction. LDW uses a
camera sensor to detect the lane
markings at speeds of 56 km/h
(35 mph) or greater.
{ WarningThe LDW system does not steer
the vehicle. The LDW system
may not: .
Provide enough time to avoid
a crash. .
Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or headlamps
are blocked by dirt, snow,
or ice; if they are not in
(Continued)

Black plate (62,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-62 Driving and Operating Warning (Continued) proper condition; or if the sun
shines directly into the
camera. .
Detect road edges. .
Detect lanes on winding or
hilly roads.
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions. How the System Works The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@ on
the center stack. The control
indicator will light when LDW is on.
When LDW is on,
@ is green if
LDW is available to warn of a lane
departure. If the vehicle crosses a
detected lane marking without using
the turn signal in that direction,
@changes to amber and flashes.
Additionally, there will be three
beeps, or the driver seat will pulse
three times on the right or left,
depending on the lane departure
direction. When the System Does Not
Seem to Work Properly The system may not detect lanes as
well when there are: .
Close vehicles ahead. .
Sudden lighting changes, such
as when driving through tunnels. .
Banked roads.
If the LDW system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
LDW alerts may occur due to tar
marks, shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LDW off if these
conditions continue.

Black plate (46,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-46 Vehicle Care The vehicle may not be equipped
with all of the fuses, relays, and
features shown.
Number Usage
1 Accessory Power
Outlet 2
2 SEO Retained
Accessory Power
3 Universal Garage
Door Opener/Inside
Rearview Mirror
6 Body Control
Module 3
7 Body Control
Module 5
8 Driver Window
Switch/Mirror Switch
9 Spare
10 Accessory Power
Outlet Retained
Accessory Power
11 Accessory Power
Outlet Battery

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-6 INDEX
HHalogen Bulbs . . . . . . . . . . . . . . . . 10-36
Hazard Warning Flashers . . . . . . . 6-4
Head Restraints . . . . . . . . . . . . . . . . 3-2
Headlamps
Aiming . . . . . . . . . . . . . . . . . . . . . . 10-36
Automatic . . . . . . . . . . . . . . . . . . . . . . 6-3
Bulb Replacement . . . . . . . . . . 10-36
Daytime Running
Lamps (DRL) . . . . . . . . . . . . . . . . . 6-3
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-36
High-Beam On Light . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lamps On Reminder . . . . . . . . . 5-26
Heated
Steering Wheel . . . . . . . . . . . . . . . . 5-3
Heated and Cooled Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Heated Mirrors . . . . . . . . . . . . . . . . . 2-17
Heater
Engine . . . . . . . . . . . . . . . . . . . . . . . . 9-28
High-Beam On Light . . . . . . . . . . . 5-26 High-Speed Operation . . . . . . . . 10-60
Hill and Mountain Roads . . . . . . . 9-11
Hill Descent Control (HDC) . . . . 9-51
Hill Descent Control Light . . . . . . 5-22
Hill Start Assist (HSA) . . . . . . . . . 9-48
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . . . 3-11
I Idle System
Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
Ignition Positions . . . . . . . . . . . . . . 9-24
Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . . . 10-34
Immobilizer . . . . . . . . . . . . . . . . . . . . 2-12
Indicator
Vehicle Ahead . . . . . . . . . . . . . . . . 5-23
Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . 3-32
Infotainment . . . . . . . . . . . . . . . . . . . . 7-1
Infotainment System . . . . . . . . . . 13-15
Instrument Cluster . . . . . . . . . . . . . . 5-9
Instrument Panel
Storage Area . . . . . . . . . . . . . . . . . . 4-1 Interior Rearview Mirrors . . . . . . . 2-19
Introduction . . . . . . . . . . . . . . . . . . . . . . . iii
J Jump Starting . . . . . . . . . . . . . . . . . 10-87
K Key and Lock Messages . . . . . . . 5-35
Keyless Entry
Remote (RKE) System . . . . . . . . 2-4
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
L Labeling, Tire Sidewall . . . . . . . . 10-52
Lamps
Auxiliary Roof
Mounted Lamp . . . . . . . . . . . . . . . 6-5
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Daytime Running (DRL) . . . . . . . 6-3
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Exterior Controls . . . . . . . . . . . . . . . 6-1
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . . 6-2
Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Malfunction Indicator . . . . . . . . . 5-18

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-8 INDEX Messages
Airbag System . . . . . . . . . . . . . . . . 5-37
Battery Voltage and
Charging . . . . . . . . . . . . . . . . . . . . 5-31
Brake System . . . . . . . . . . . . . . . . 5-32
Compass . . . . . . . . . . . . . . . . . . . . . 5-32
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-33
Engine Cooling System . . . . . . . 5-33
Engine Oil . . . . . . . . . . . . . . . . . . . . 5-34
Engine Power . . . . . . . . . . . . . . . . 5-34
Fuel System . . . . . . . . . . . . . . . . . . 5-35
Key and Lock . . . . . . . . . . . . . . . . . 5-35
Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
Object Detection System . . . . . 5-35
Ride Control System . . . . . . . . . . 5-36
Safety Belt . . . . . . . . . . . . . . . . . . . . 5-37
Security . . . . . . . . . . . . . . . . . . . . . . 5-38
Steering System . . . . . . . . . . . . . . 5-38
Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
Transmission . . . . . . . . . . . . . . . . . 5-39
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-31
Vehicle Reminder . . . . . . . . . . . . . 5-41
Vehicle Speed . . . . . . . . . . . . . . . . 5-42
Washer Fluid . . . . . . . . . . . . . . . . . 5-42 Mirrors
Automatic Dimming . . . . . . . . . . . 2-17
Automatic Dimming
Rearview . . . . . . . . . . . . . . . . . . . . 2-19
Blind Spot . . . . . . . . . . . . . . . . . . . . 2-17
Convex . . . . . . . . . . . . . . . . . . . . . . . 2-14
Folding . . . . . . . . . . . . . . . . . . . . . . . 2-16
Heated . . . . . . . . . . . . . . . . . . . . . . . 2-17
Power . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Tilt in Reverse . . . . . . . . . . . . . . . . 2-18
Trailer Tow . . . . . . . . . . . . . . . . . . . . 2-14
Mirrors, Interior Rearview . . . . . . 2-19
Monitor System, Tire
Pressure . . . . . . . . . . . . . . . . . . . . 10-61
N Navigation
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 14-3
New Vehicle Break-In . . . . . . . . . . 9-23
Noise Control System . . . . . . . . 10-32 O Object Detection System
Messages . . . . . . . . . . . . . . . . . . . . 5-35
Odometer . . . . . . . . . . . . . . . . . . . . . . 5-11
Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 9-6
Driving . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Recovery . . . . . . . . . . . . . . . . . . . . . . 9-5
Oil
Engine . . . . . . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . .10-11
Engine Oil Pressure
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-12
Messages . . . . . . . . . . . . . . . . . . . . 5-34
Pressure Light . . . . . . . . . . . . . . . . 5-25
Older Children, Restraints . . . . . 3-30
Online Owner Center . . . . . . . . . . 13-4
OnStar . . . . . . . . . . . . . . . . . . . . . . . 13-15
OnStar ®
System, In Brief . . . . . . . . . . . . . . 1-22
OnStar ®
Additional
Information . . . . . . . . . . . . . . . . . . . 14-6
OnStar ®
Connections . . . . . . . . . . 14-4
OnStar ®
Emergency . . . . . . . . . . . 14-2
OnStar ®
Navigation . . . . . . . . . . . . 14-3
OnStar ®
Overview . . . . . . . . . . . . . 14-1

Black plate (9,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-9OnStar ®
Security . . . . . . . . . . . . . . 14-3
OnStar ®
Vehicle
Diagnostics . . . . . . . . . . . . . . . . . . 14-6
Operating Mode
Overheated Engine
Protection . . . . . . . . . . . . . . . . . 10-23
Ordering
Service Publications . . . . . . . . .13-11
Outlets
Power . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . . . 10-23
Overheating, Engine . . . . . . . . . . 10-21
PPark
Shifting Into . . . . . . . . . . . . . . . . . . . 9-30
Shifting Out of . . . . . . . . . . . . . . . . 9-31
Parking
Brake . . . . . . . . . . . . . . . . . . . . . . . . . 9-47
Brake and P (Park)
Mechanism Check . . . . . . . . 10-34
Over Things That Burn . . . . . . . 9-32 Parking or Backing
Assistance Systems . . . . . . . . . . 9-56
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . . 5-17
Passenger Compartment Air
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Passenger Sensing System . . . 3-24
Perchlorate Materials
Requirements, California . . . . . 10-3
Personalization
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-42
Pickup Conversion to
Chassis Cab . . . . . . . . . . . . . . . . . 9-92
Power
Door Locks . . . . . . . . . . . . . . . . . . . . 2-9
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Outlets . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Protection, Battery . . . . . . . . . . . . . 6-9
Retained Accessory (RAP) . . . 9-29
Seat Adjustment . . . . . . . . . . . . . . . 3-3
Steering Fluid . . . . . . . . . . . . . . . 10-24
Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Pregnancy, Using Safety
Belts . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Privacy
Vehicle Data Recording . . . . . 13-14 Program
Courtesy Transportation . . . . . . 13-8
Proposition 65 Warning,
California . . . . . . . . . . . . . . . . . . . . . 10-2
R Radio Frequency
Identification (RFID) . . . . . . . . . 13-12
Radio Frequency
Statement . . . . . . . . . . . . . . . . . . . 13-12
Reading Lamps . . . . . . . . . . . . . . . . . 6-7
Rear Axle . . . . . . . . . . . . . . . . . . . . . 10-31
Locking . . . . . . . . . . . . . . . . . . . . . . . 9-52
Rear Seats . . . . . . . . . . . . . . . . . . . . . 3-9
Rear Windows . . . . . . . . . . . . . . . . . 2-22
Rearview Mirrors
Automatic Dimming . . . . . . . . . . . 2-19
Reclining Seatbacks . . . . . . . . . . . . 3-4
Recommended Fluids and
Lubricants . . . . . . . . . . . . . . . . . . . 11-12
Records
Maintenance . . . . . . . . . . . . . . . . .11-16
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . . . . 10-91
Reimbursement Program,
GM Mobility . . . . . . . . . . . . . . . . . . 13-5