
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
248 Climate Controls
Manual Operation
O:Press to turn the climate control
system on or off. When off is
selected, the system will stop air
from flowing into the cabin. If on is
selected, any other button press
occurs, or a knob is turned, the
climate control system will turn on
and operate to the current setting.
9: 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 : 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 :
PressY,\,[, or-to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
Y: Air is directed to the instrument
panel outlets.
\: Air is divided between the
instrument panel and floor outlets.
Some air is directed toward the
windshield and side window outlets.
[: Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
-: This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents. The system
automatically forces outside air into
the vehicle and the air conditioning
compressor will run, unless the
outside temperature is close to
freezing.
0: Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The air
conditioning compressor also comes
on, unless the outside temperature
is below freezing.
Do not drive the vehicle until all
windows are clear.
See Air Vents 0250.
A/C : Press to turn the air
conditioning system on or off. An
indicator light comes on to show
that the air conditioning is enabled.
If the fan is turned off, the air
conditioner will not run. The A/C
light will stay on even if the outside
temperatures are below freezing.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Climate Controls 249
@:Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle. The air
conditioning compressor also comes
on when this mode is activated.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
K: Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on.
The rear window defogger only
works when the ignition is in ON/
RUN. The defogger turns off if the
ignition is turned to ACC/
ACCESSORY or LOCK/OFF.
Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
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,
press
Kto heat the mirrors. See
Heated Mirrors 048.
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.
Some vehicles may have the
exterior temperature sensor in the
passenger side mirror instead of the
front grille area.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Climate Controls 251
1. Open the lower glove box doorcompletely.
2. Remove the four screws from around the lower glove box.
The door does not need to be
removed to access the screws.
3. Close the lower glove box doorand pull it from its frame to
remove the entire unit.
4. Release the two tabs holding
the service door. Open the
service door and remove the
old filter.
5. Install the new air filter.
6. Close the service door and secure the tabs.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional
assistance is needed.
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained
and certified technicians. The air
conditioning evaporator should
never be repaired or replaced by
one from a salvage vehicle.
It should only be replaced by a new
evaporator to ensure proper and
safe operation.
During service, all refrigerants
should be reclaimed with proper
equipment. Venting refrigerants
directly to the atmosphere is harmful
to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite,
or other health-based concerns.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 377
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0478.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it (Continued)
Warning (Continued)
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem. If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.
Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer Towing
0 323.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 379
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fan(s), the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.Power Steering Fluid
(1500 Series)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
SeeEngine Compartment Overview
0 359 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired. Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the ignition off and let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the
dipstick.
The level should be between the
ADD and FULL marks. If necessary,
add only enough fluid to bring the
level up to the hashed area between
the ADD and FULL marks.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
406 Vehicle Care
(2) Tire Width:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item 3 of the light truck
(LT-Metric) tire illustration, it
would mean that the tire's
sidewall is 75 percent as high as
it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Load Range
:Load Range. (7) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning. Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire Pressure
0 408.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
470 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and
Lubricants 0464.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Application Capacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and charge amount, see the refrigerant label under thehood. See your dealer for more information.
Cooling System
4.3L V6 1500 Series 15.1 L 15.9 qt
5.3L V8 1500 Series (L83) 16.0 L 16.9 qt
5.3L V8 1500 Series (L8B eAssist) 16.4 L 17.3 qt
6.0L V8 2500 Series and 3500 Series (L96&MQ7) 16.3 L 17.1 qt
6.0L V8 2500 Series and 3500 Series (LC8/L96&MYD) 15.4. L 16.3 qt
6.2L V8 1500 Series 15.7 L 16.6 qt
Engine Oil with Filter
4.3L V6 5.7 L 6.0 qt
5.3L V8; 6.2L V8 7.6 L 8.0 qt

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
498 Index
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 357
Accessory Power . . . . . . . . . . . . . . . 277
Active Fuel Management
®. . . . . . 281
Add-On Electrical Equipment . . . 350
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . 350
Additional Information OnStar
®. . . . . . . . . . . . . . . . . . . . . . 493
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . 461
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . . 273
Adjustments Lumbar, Front Seats . . . . . . . . . . . . 58
Agreements Trademarks and License . . . . . 238
Air Cleaner/Filter, Engine . . . . . . . 371
Air Conditioning . . . . . .243, 245, 246
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . 250
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 250
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 87
How Does an AirbagRestrain? . . . . . . . . . . . . . . . . . . . . . 77
Passenger Sensing System . . . . 81 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 77
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 78
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 75
Where Are the Airbags? . . . . . . . . 74
Airbags
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 86
Light On-Off . . . . . . . . . . . . . . . . . . 141
On-Off Light . . . . . . . . . . . . . . . . . . 141
On-Off Switch . . . . . . . . . . . . . . . . . . 79
Passenger Status Indicator . . . 143
Readiness Light . . . . . . . . . . . . . . 141
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 85
System Check . . . . . . . . . . . . . . . . . . 73
Alarm Vehicle Security . . . . . . . . . . . . . . . . 43
All-Season Tires . . . . . . . . . . . . . . . . 401
All-Terrain Tires . . . . . . . . . . . . . . . . . 402
AM-FM Radio . . . . . . . . . . . . . . 197, 199
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . 203
Multi-band . . . . . . . . . . . . . . . . . . . . 203
Antilock Brake System (ABS) . . . 297