air condition GMC SIERRA DENALI 2015 User Guide

Black plate (33,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-33
Door Ajar Messages DOOR OPEN This message displays and a chime
may sound if a door is not fully
closed. Stop and turn off the
vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
HOOD OPEN This message displays and a chime
may sound if the hood is not fully
closed. Stop and turn off the
vehicle, check the hood for
obstructions, and close the hood
again. Check to see if the message
still appears on the DIC. Engine Cooling System
Messages A/C OFF DUE TO HIGH
ENGINE TEMP This message displays when the
engine coolant becomes hotter than
the normal operating temperature.
See Engine Coolant Temperature
Gauge on page 5-13 . To avoid
added strain on a hot engine, the air
conditioning compressor
automatically turns off. When the
coolant temperature returns to
normal, the air conditioning
compressor turns back on. You can
continue to drive your vehicle.
If this message continues to appear,
have the system repaired by your
dealer as soon as possible to avoid
damage to the engine. ENGINE OVERHEATING IDLE
ENGINE This message displays when the
engine coolant temperature is too
hot. Stop and allow the vehicle to
idle until it cools down. See Engine
Coolant Temperature Gauge on
page 5-13 .
When towing, use Tow/Haul mode
to prevent damage to the engine or
transmission. See Tow/Haul Mode
on page 9-39 .
ENGINE OVERHEATED STOP
ENGINE This message displays and a chime
may sound if the engine cooling
system reaches unsafe
temperatures for operation. Stop
and turn off the vehicle as soon as it
is safe to do so to avoid severe
damage. This message clears when
the engine has cooled to a safe
operating temperature.

Black plate (37,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-37TRACTION CONTROL OFF This message displays when the
traction control has been turned off.
See Traction Control/Electronic
Stability Control on page 9-49 .
TRACTION CONTROL ON This message displays when the
traction control is active. See
Traction Control/Electronic Stability
Control on page 9-49 .
STABILITRAK OFF This message displays when the
StabiliTrak system has been turned
off. Adjust your driving accordingly.
To limit wheel spin and realize the
full benefits of the stability
enhancement system, you should
normally leave StabiliTrak on. See
Traction Control/Electronic Stability
Control on page 9-49 . STABILITRAK OFF may also
display when the stability control
has been automatically disabled.
The following conditions can cause
this message to appear: .
The system is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time. .
The brake system warning light
is on. See Brake System
Warning Light on page 5-21 ..
The stability system takes longer
than usual to complete its
diagnostic checks due to driving
conditions. .
An engine or vehicle-related
problem has been detected and
the vehicle needs service. See
your dealer. .
The transfer case is in
Four-Wheel Drive Low.
The message turns off as soon as
the conditions that caused the
message to be displayed are no
longer present. Airbag System Messages SERVICE AIRBAG This message displays if there is a
problem with the airbag system.
Take the vehicle to your dealer for
service.
Safety Belt Messages SHIFTER LOCKED. BUCKLE
SEATBELT This message displays if the vehicle
is equipped with the Safety Belt
Assurance System and the driver
and front outboard passenger,
if present, safety belts are not
buckled. The vehicle will not shift
out of P (Park). Buckle the safety
belt(s) to unlock the shift lever.
This system may not allow the
vehicle to shift out of P (Park) if an
object - such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device - is on the
front outboard passenger seat.

Black plate (38,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-38 Instruments and Controls If this happens, remove the object
from the seat or buckle the
safety belt.
If the driver or front outboard
passenger unbuckles their safety
belt while driving, the safety belt
reminder chime and light(s) will
come on. See Safety Belt
Reminders on page 5-15 .
SHIFTER UNLOCKED. BRAKE
TO SHIFT This message displays when the
Safety Belt Assurance System times
out and allows the vehicle to be
shifted out of P (Park) after
30 seconds following brake apply.
See “ Safety Belts ” and “ Child
Restraints ” in the Index for
information about the importance of
proper restraint use.
This system may not function
properly if the airbag readiness light
is on. See Airbag Readiness Light
on page 5-16 . Security Messages SERVICE THEFT DETERRENT
SYSTEM This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart, so you may want to take the
vehicle to your dealer before turning
off the engine. See Immobilizer
Operation on page 2-13 .
Steering System
Messages STEERING ASSIST IS
REDUCED DRIVE WITH CARE This message may display if a
problem occurs with the electric
power steering system. If this
message appears, steering effort
may be slightly higher than normal.
The vehicle is still safe to drive. Use
caution while in reduced assist
mode. If this message is persistent or appears repeatedly, take the
vehicle to your dealer for service.
See Steering on page 9-4 .
SERVICE POWER STEERING This message displays when there
is a problem with electric power
steering. Take the vehicle to your
dealer for service. See Steering on
page 9-4 .
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 on page 5-25 . Several
conditions may cause this message
to appear. See Tire Pressure
Monitor Operation on page 10-62 .

Black plate (39,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-39If 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 on page 10-65 ,
Tire Rotation on page 10-65 , Tire
Pressure Monitor System on
page 10-61 , and Tire Pressure on
page 10-59 . 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 on page 5-25 . 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
on page 10-50 , Vehicle Load Limits
on page 9-15 , and Tire Pressure on
page 10-59 . The DIC also shows
the tire pressure values. See Driver
Information Center (DIC) on
page 5-27 . 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.
FOR 4WD LOW SHIFT TO
NEUTRAL
If a four-wheel drive shift into 4
n is
requested, and the vehicle speed is
correct, but the transmission is not
in N (Neutral), this message will
display until the transmission is
shifted to N (Neutral).

Black plate (45,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-45adjusted to this level. To set the
maximum startup volume, press +
or − to increase or decrease.
Vehicle Select and the following may
display: .
Climate and Air Quality .
Collision/Detection Systems .
Comfort and Convenience .
Lighting .
Power Door Locks .
Remote Lock, Unlock, Start
Climate and Air Quality Select the Climate and Air Quality
menu and the following may display: .
Auto Fan Max Speed .
Auto Rear Defog
Auto Fan Max Speed
This feature will set the maximum
auto fan speed.
Select Low, Medium, or High. Auto Rear Defog
If equipped, this feature will
automatically turn on the rear
window defogger when it is cold
outside.
Select Off or On.
Collision/Detection Systems Select the Collision/Detection
Systems menu and the following
may display: .
Alert Type .
Auto Collision Preparation .
Park Assist
Alert Type
This feature will set crash alerts to
beeps or seat vibrations. This
setting affects all crash alerts
including Forward Collision Alert,
Lane Departure Warning, and Park
Assist alerts.
Select Beeps or Safety Alert Seat. Auto Collision Preparation
This feature will turn on or off the
Forward Collision Alert feature as
well as the automatic braking
capability of the Auto Collision
Preparation feature. With the Alert
and Brake setting, both Forward
Collision Alert as well as the
automatic braking capability of the
Auto Collision Preparation feature
are available. The Alert setting
disables most automatic braking
functions of the Auto Collision
Preparation feature. Some
last-second automatic braking
capability is still provided with the
Alert setting, but it is much less
likely to be triggered by most driving
conditions. Off disables all Forward
Collision Alert and automatic
braking capabilities of the Auto
Collision Preparation feature.
Select Off, Alert and Brake, or Alert.
See Object Detection System
Messages on page 5-35 .

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Climate Controls 8-1
Climate Controls Climate Control Systems Dual Automatic Climate Control
System . . . . . . . . . . . . . . . . . . . . . . 8-1
Air Vents Air Vents . . . . . . . . . . . . . . . . . . . . . . 8-4
Maintenance Passenger Compartment Air
Filter . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Service . . . . . . . . . . . . . . . . . . . . . . . 8-6 Climate Control Systems Dual Automatic Climate Control System With this system the heating, cooling, and ventilation in the vehicle can be
controlled.
1. Driver Temperature Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Fan Control
5. Defrost
6. Passenger Temperature Control 7. AUTO (Automatic Operation)
8. Air Recirculation
9. Power Button
10. Rear Window Defogger
11. SYNC (Synchronized
Temperature)

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 (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Climate Controls 8-3Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
Y (Vent): Air is directed to the
instrument panel outlets.
\ (Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
toward the windshield and side
window outlets.
[ (Floor): Air is directed to the
floor outlets, with some to the
windshield, side window outlets, and
second row floor outlets.
- (Defog): 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 (Defrost): 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 on page 8-4 .
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.
@ (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. 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 (Rear Window Defogger):
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
(Continued)

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
8-6 Climate Controls
3. Close the lower glove box door
and 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.

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-6 Driving and Operating If the vehicle starts to slide, follow
these suggestions: .
Ease your foot off the
accelerator pedal and steer the
way you want the vehicle to go.
The vehicle may straighten out.
Be ready for a second skid if it
occurs. .
Slow down and adjust your
driving according to weather
conditions. Stopping distance
can be longer and vehicle
control can be affected when
traction is reduced by water,
snow, ice, gravel, or other
material on the road. Learn to
recognize warning clues — such
as enough water, ice, or packed
snow on the road to make a
mirrored surface — and slow
down when you have any doubt. .
Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle speed
by shifting to a lower gear. Any
sudden changes could cause
the tires to slide. Remember: Antilock brakes help
avoid only the braking skid.
Off-Road Driving Four-wheel-drive vehicles can be
used for off-road driving. Vehicles
without four-wheel drive and
vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR)
tires must not be driven off-road
except on a level, solid surface. For
contact information about the
original equipment tires, see the
warranty manual.
One of the best ways for successful
off-road driving is to control the
speed.
{ Warning
When driving off-road, bouncing
and quick changes in direction
can easily throw you out of
position. This could cause you to
lose control and crash. You and
your passengers should always
wear safety belts. Before Driving Off-Road .
Have all necessary maintenance
and service work completed. .
Fuel the vehicle, fill fluid levels,
and check inflation pressure in
all tires, including the spare,
if equipped. .
Read all the information about
four-wheel-drive vehicles in this
manual. .
Remove any underbody air
deflector, if equipped. Re-attach
the air deflector after off-road
driving. .
See Hill Descent Control (HDC)
on page 9-51 .
Know the local laws that apply to
off-road driving.
To gain more ground clearance if
needed, it may be necessary to
remove the front fascia lower air
dam. However, driving without the
air dam reduces fuel economy.