2015 GMC SIERRA air condition

Black plate (18,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-18 Instruments and Controls
Warning (Continued)
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light on page 5-16 for more
information, including important
safety information.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
It should go out when the engine is
started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
See
Battery Voltage and Charging
Messages on page 5-31.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors the operation
of the vehicle to ensure emissions
are at acceptable levels, helping to
maintain a clean environment. The
malfunction indicator lamp comes
on when the vehicle is placed in
ON/RUN, as a check to show it is working. If it does not, have the
vehicle serviced by your dealer. See
Ignition Positions on page 9-24.
If the malfunction indicator lamp
comes on while the engine is
running, this indicates that the OBD
II system has detected a problem
and diagnosis and service might be
required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system also
assists the service technician in
correctly diagnosing any
malfunction.

Black plate (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-19
{Caution
If the vehicle is continually driven
with this light on, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
{Caution
Modifications made to the engine,
transmission, exhaust, intake,
or fuel system of the vehicle or
the replacement of the original
tires with other than those of the
same Tire Performance Criteria
(TPC) can affect the vehicle's
emission controls and can cause
this light to come on.
Modifications to these systems(Continued)
Caution (Continued)
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test. See
Accessories and Modifications on
page 10-3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.
To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled as
soon as it is possible.
If the light continues to flash, find a
safe place to stop and park the
vehicle. Turn the vehicle off, wait at
least 10 seconds, and restart the
engine. If the light is still flashing,
follow the previous steps and see
your dealer for service as soon as
possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.
The following may correct an
emission control system
malfunction:
.Check that the fuel cap is fully
installed. See Filling the Tank on
page 9-66. The diagnostic
system can determine if the fuel
cap has been left off or
improperly installed. A loose or
missing fuel cap allows fuel to
evaporate into the atmosphere.

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.
SeeEngine 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 5-37
TRACTION CONTROL OFF
This message displays when the
traction control has been turned off.
SeeTraction 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. SeeSafety 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 5-39
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.
SeeTire 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 4nis
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 5-45
adjusted 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 ControlSystem . . . . . . . . . . . . . . . . . . . . . . 8-1
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . 8-4
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . 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)