
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
164 Instruments and Controls SERVICE POWER STEERING
(2500/3500 Series) This message displays when there
is a problem with the power steering
assist system. If this message
displays the vehicle can be driven
but should be repaired as soon as
possible. See your dealer. See
Steering 0 255 .
Tire Messages SERVICE TIRE MONITOR
SYSTEM If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
system is not working properly. The
tire pressure light also flashes and
then remains on during the same
ignition cycle. See Tire Pressure
Light 0 150 . Several conditions may
cause this message to appear. See
Tire Pressure Monitor Operation
0 411 . 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.
See Tire Inspection 0 414 , Tire
Rotation 0 415 , Tire Pressure
Monitor System 0 410 , and Tire
Pressure 0 408 .
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 0 150 . 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 0 400 ,
Vehicle Load Limits 0 265 , and Tire
Pressure 0 408 . The DIC also
shows the tire pressure values.
See Driver Information Center (DIC)
(Base Level Cluster) 0 152 or Driver
Information Center (DIC) (Uplevel
and Denali Cluster) 0 154 .
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
180 Lighting The high-beam headlamps remain
on, under the automatic control,
until one of the following situations
occurs:
.
The system detects an
approaching vehicle's
headlamps.
.
The system detects a preceding
vehicle's taillamps.
.
The outside light is bright
enough that high-beam
headlamps are not required.
.
The vehicle's speed drops below
20 km/h (12 mph).
.
The IntelliBeam system can be
disabled by the high/low-beam
changer or the flash-to-pass
feature. If this happens, the high/
low-beam changer must be
activated on then off within
five seconds to reactivate the
IntelliBeam system. The
instrument cluster light will come
on to indicate the IntelliBeam is
reactivated.
See Headlamp High/Low-Beam
Changer 0 180 and
Flash-to-Pass 0 181 . The high beams may not turn off
automatically if the system cannot
detect another vehicle's lamps
because of any of the following:
.
The other vehicle's lamps are
missing, damaged, obstructed
from view, or otherwise
undetected.
.
The other vehicle's lamps are
covered with dirt, snow, and/or
road spray.
.
The other vehicle's lamps cannot
be detected due to dense
exhaust, smoke, fog, snow, road
spray, mist, or other airborne
obstructions.
.
The vehicle's windshield is dirty,
cracked, or obstructed by
something that blocks the view
of the light sensor.
.
The vehicle is loaded such that
the front end points upward,
causing the light sensor to aim
high and not detect headlamps
and taillamps.
.
Driving on winding or hilly roads. The automatic high-beam
headlamps may need to be disabled
if any of the above conditions exist.
Exterior Lamps Off
Reminder A reminder chime sounds when the
headlamps or parking lamps are
manually turned on, the ignition is
off, and a door is open. To disable
the chime, turn the lamps off.
Headlamp High/
Low-Beam Changer Push the turn signal lever toward
the instrument panel to change the
headlamps from low to high beam.
Pull the turn signal lever toward you
and release it to return to low-beam
headlamps.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Climate Controls 243
Climate Controls Climate Control Systems Climate Control Systems (with
Heater Only) . . . . . . . . . . . . . . . . 243
Climate Control Systems (with
Air Conditioning) . . . . . . . . . . . . 245
Dual Automatic Climate
Control System . . . . . . . . . . . . . 246
Air Vents Air Vents . . . . . . . . . . . . . . . . . . . . . 250
Maintenance Passenger Compartment Air
Filter . . . . . . . . . . . . . . . . . . . . . . . . 250
Service . . . . . . . . . . . . . . . . . . . . . . . 251 Climate Control Systems Climate Control Systems (with Heater Only) With this system, the heating and ventilation can be controlled.
1. Fan Control
2. Air Recirculation
3. Air Delivery Mode Controls 4. Defrost
5. TEMP (Temperature Control)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Climate Controls 245
Climate Control Systems (with Air Conditioning) With this system the heating, cooling, and ventilation can be controlled.
1. Fan Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Defrost
5. TEMP (Temperature Control)
6.
K (Rear Window Defogger, If
Equipped)
f (Outside Heated Mirror, If
Equipped)
8 (Outside Air, If Equipped) 7.
@ Air Recirculation
TEMP (Temperature Control) :
Turn clockwise or counterclockwise
to increase or decrease the
temperature inside the vehicle.
9 (Fan Control) : Turn clockwise
or counterclockwise to increase or
decrease the fan speed. Turn the
knob all the way counterclockwise
to turn the fan off. Air Delivery Mode Controls :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Y (Vent) : Air is directed to the
instrument panel outlets.
\ (Bi-Level) : Air is divided
between the instrument panel and
floor outlets.
[ (Floor) : Air is directed to the
floor outlets, with some air directed
to the windshield and side window
outlets.
- (Defog) : This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents.
0 (Defrost) : Press to clear the
windshield of fog or frost more
quickly. Air is directed to the
windshield and the 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
246 Climate Controls Do not drive the vehicle until all the
windows are clear.
See Air Vents 0 250 .
@ (Recirculation) : 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.
8 (Outside Air, If Equipped) :
Press to turn the outside air mode
on. An indicator light on the button
comes on to show that outside is
on. When selected, air from outside
the vehicle circulates throughout the
vehicle. The recirculation mode
cannot be used with the outside
air mode.
A/C (Air Conditioning) : 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. Rear Window Defogger
K (Rear Window Defogger) :
If equipped, 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.
If equipped with heated outside
mirrors, they turn on when the rear
window defogger button is on. They
help to clear fog or frost from the
surface of the mirrors. See Heated
Mirrors 0 48 .
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. Dual Automatic Climate
Control System With this system the heating,
cooling, and ventilation in the
vehicle can be controlled.
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Climate Controls 247
1. Driver Temperature Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Fan Control
5. Defrost
6. Passenger Temperature
Control
7. SYNC (Synchronized
Temperature)
8. Rear Window Defogger
9. Power Button
10. Air Recirculation
11. AUTO (Automatic Operation) 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.

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 :
Press
Y ,
\ ,
[ , 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 0 250 .
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. CautionUsing 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
K to heat the mirrors. See
Heated Mirrors 0 48 .
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.