
Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
1-12 In Brief
Throttle and Brake Pedal
Adjustment If equipped, the position of the
throttle and brake pedals can be
changed.
The switch used to adjust the
pedals is on the center stack, below
the climate controls.
Lift the switch up to move the
pedals closer to your body. Press
the switch down to move the
pedals away. See Adjustable Throttle and Brake
Pedal on page 9-23 .
Interior Lighting Dome Lamps
There are dome lamps in the
overhead console and the headliner,
if equipped.
To change the dome lamp settings,
press the following:
OFF: Turns the lamps off, even
when a door is open. DOOR: The lamps come on
automatically when a door is
opened.
ON: Turns all dome lamps on.
Reading Lamps
There are reading lamps in the
overhead console and the headliner,
if equipped. To operate, the ignition
must be in the ACC/ACCESSORY
or ON/RUN position or using
Retained Accessory Power (RAP). 

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-5To set the clock display:
1. Select SETTINGS from the
Home Page, then select Time
and Date.
2. Select Clock Display.
3. Turn the MENU knob to Off
or On.
4. Press the MENU knob to select.
Press
o BACK to go to the last
menu and save the changes.
Setting the Time and Date with
Touchscreen Controls To set the time:
1. Press the SETTINGS screen
button from the Home Page,
then press Time and Date.
2. Press Set Time and press
« or
ª to increase or decrease
hours, minutes, and AM or PM.
Press 12 – 24 Hr for 12 or
24 hour clock.
3. Press the
} screen button to go
back to the previous menu. Auto Set requires an OnStar
subscription.
If auto timing is set, the time
displayed on the clock may not
update immediately when driving
into a new time zone.
To set the date:
1. Press the SETTINGS screen
button from the Home Page,
then press Time and Date.
2. Press Set Date and press
« or
ª to increase or decrease
month, day, or year.
3. Press the
} screen button to go
back to the previous menu.
To set the clock display:
1. Press the SETTINGS screen
button and press Time and Date.
2. Press Clock Display and press
OFF or ON to turn the clock
display off or on.
3. Press the
} screen button to go
back to the previous menu. Power Outlets Accessory power outlets can be
used to plug in electrical equipment,
such as a cell phone, MP3
player, etc.
The vehicle may have up to four
accessory power outlets.
Vehicles with a Center Console .
One or two in front of the
cupholders on the center
console. .
One inside the center console. .
One on the rear of the center
console.
Vehicles with Bench Seats .
One on the center stack below
the climate control system. .
One or two in the storage area
on the bench seat.
Lift the cover to access and replace
when not in use. 

Black plate (2,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
8-2 Climate Controls Automatic Operation
The system automatically controls
the fan speed, air delivery, air
conditioning, and recirculation in
order to heat or cool the vehicle to
the desired temperature.
When the indicator light is on, the
system is in full automatic operation.
If the air delivery mode or fan
setting is manually adjusted, the
auto indicator turns off and displays
will show the selected settings.
To place the system in
automatic mode:
1. Press AUTO.
2. Set the driver and passenger
temperature.
To find your comfort setting, start
with 22°C (72°F) and allow the
system time to stabilize. Then
adjust the temperature as
needed for best comfort.
To improve fuel efficiency and to
cool the vehicle faster, recirculation
may be automatically selected in
warm weather. The recirculation light will not come
on when automatically controlled.
Press
@ to manually select
recirculation; press it again to select
outside air.
Do not cover the solar sensor on the
top of the instrument panel near the
windshield. This sensor regulates
air temperature based on sun load.
See “ Sensors ” later in this section.
Manual Operation
O (On/Off): Press to turn the
climate control system on or off.
Outside air still enters the vehicle,
and is directed to the floor. This
direction can be changed by
pressing the air delivery mode.
9 (Fan Control): Turn clockwise
or counterclockwise to increase or
decrease the fan speed. Press the
knob to turn the fan off.
Press AUTO to return to automatic
operation. Driver and Passenger
Temperature Control: The
temperature can be adjusted
separately for the driver and
passenger.
Turn the knob clockwise or
counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC (Synchronized
Temperature): Press to link the
passenger temperature setting to
the driver setting. The SYNC
indicator light will turn on. When the
passenger setting is adjusted, the
SYNC indicator light is off.
The driver side or passenger side
temperature display shows the
temperature setting increasing or
decreasing.
Air Delivery Mode Control:
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button. 

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 (2,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-2 Driving and Operating E85 or FlexFuel . . . . . . . . . . . . . . 9-65
Filling the Tank . . . . . . . . . . . . . . 9-66
Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . 9-67
Trailer Towing General Towing
Information . . . . . . . . . . . . . . . . . 9-68
Driving Characteristics and
Towing Tips . . . . . . . . . . . . . . . . 9-68
Trailer Towing . . . . . . . . . . . . . . . . 9-71
Towing Equipment . . . . . . . . . . . 9-78
Trailer Sway
Control (TSC) . . . . . . . . . . . . . . 9-87
Conversions and Add-Ons Add-On Electrical
Equipment . . . . . . . . . . . . . . . . . 9-88
Adding a Snow Plow or
Similar Equipment . . . . . . . . . . 9-88
Pickup Conversion to
Chassis Cab . . . . . . . . . . . . . . . 9-92 Driving Information Distracted Driving Distraction comes in many forms
and can take your focus from the
task of driving. Exercise good
judgment and do not let other
activities divert your attention away
from the road. Many local
governments have enacted laws
regarding driver distraction. Become
familiar with the local laws in
your area.
To avoid distracted driving, always
keep your eyes on the road, hands
on the wheel, and mind on the drive. .
Do not use a phone in
demanding driving situations.
Use a hands-free method to
place or receive necessary
phone calls. .
Watch the road. Do not read,
take notes, or look up
information on phones or other
electronic devices. .
Designate a front seat
passenger to handle potential
distractions. .
Become familiar with vehicle
features before driving, such as
programming favorite radio
stations and adjusting climate
control and seat settings.
Program all trip information into
any navigation device prior to
driving. .
Wait until the vehicle is parked
to retrieve items that have fallen
to the floor. .
Stop or park the vehicle to tend
to children. .
Keep pets in an appropriate
carrier or restraint. .
Avoid stressful conversations
while driving, whether with a
passenger or on a cell phone. 

Black plate (24,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-24 Driving and Operating No adjustment to the pedals can be
made when the vehicle is in
R (Reverse) or while using cruise
control.
The switch used to adjust the
pedals is on the center stack, below
the climate controls.
Lift the switch up to move the
pedals closer to your body. Press
the switch down to move the
pedals away. Before you start driving, fully press
the brake pedal to confirm the
adjustment is right for you. While
driving, make only small
adjustments.
The vehicle may have a memory
function, which lets pedal settings
be saved and recalled. See Memory
Seats on page 3-5 .
Ignition Positions
Vehicles with Key Access have an
ignition switch with four different
positions. To shift out of P (Park), the ignition
must be in ON/RUN or ACC/
ACCESSORY and the regular brake
pedal must be applied.
1 (STOPPING THE ENGINE/LOCK/
OFF): When the vehicle is stopped,
turn the ignition switch to LOCK/
OFF to turn the engine off. Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) on page 9-29 .
This position locks the ignition and
steering wheel. It also locks the
transmission on automatic
transmission vehicles. The key can
be removed in LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.