2013 GMC SIERRA air condition

Black plate (28,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-28 Driving and Operating
Engine Coolant Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
−18°C (0°F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist
which will prevent engine coolant
heater operation at temperatures
above−18°C (0°F).
If the vehicle has a diesel engine,
see the Duramax Diesel supplement
for more information.
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The cord is
secured to the Engine
Compartment Fuse Block with a
clip. Carefully remove the wire tie which bundles the electrical
plug. Do not cut the
electrical cord.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{WARNING
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire. You
could be seriously injured. Plug
the cord into a properly grounded
three-prong 110-volt AC outlet.
If the cord will not reach, use a
heavy-duty three-prong extension
cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it
away from moving engine parts.
If you do not, it could be
damaged. The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. With four-wheel drive,
if the transfer case is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
(Continued)

Black plate (36,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-36 Driving and Operating
three seconds. A DIC message
displays. SeeTransmission
Messages on page 5‑44.
For iother forms of grade braking,
see Tow/Haul Mode on page 9‑37
and Cruise Control on page 9‑56.
Manual Mode
Range Selection Mode
(Allison®Transmission or
Hydra-Matic®6-Speed
Transmission)
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the
vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears. To use this feature, do the following:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column
shift lever, to select the desired
range of gears for current driving
conditions.
When M (Manual Mode) is selected
a number displays next to the M,
indicating the current gear.
This number is the highest gear that
can be used. However, the vehicle
can automatically shift to lower
gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until
the plus/minus button located on the
steering column lever is used to
change to the gear. Grade Braking is not available when
Range Selection Mode is active.
See
Tow/Haul Mode on page 9‑37.
While using Range Selection Mode,
Cruise Control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See Exhaust Brake in
the Duramax Diesel supplement.
Notice: Spinning the tires or
holding the vehicle in one place
on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.

Black plate (55,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-55
disabled. In this mode, engine
power is not reduced automatically
and the driven wheels can spin
more freely. This can cause the
brake-traction control to activate
constantly.
Notice:If the wheel(s) of one axle
is allowed to spin excessively
while the StabiliTrak
®, ABS, brake
warning lights, and any relevant
DIC messages are displayed, the
transfer case could be damaged.
The repairs would not be covered
by the vehicle warranty. Reduce
engine power and do not spin the
wheel(s) excessively while these
lights and messages are
displayed.
The TCS may activate on dry or
rough roads or under conditions
such as heavy acceleration while
turning or abrupt upshifts/downshifts
of the transmission. When this
happens, a reduction in acceleration
may be noticed, or a noise or
vibration may be heard. This is
normal. If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control will
automatically disengage. Cruise
control may be reengaged when
road conditions allow. See
Cruise
Control on page 9‑56.
StabiliTrak may also turn off
automatically if it determines that a
problem exists with the system.
If the problem does not clear itself
after restarting the vehicle, see your
dealer for service.
Vehicles with StabiliTrak have a
Trailer Sway Control (TSC) feature.
See Trailer Sway Control (TSC) on
page 9‑100.
Vehicles with StabiliTrak have a Hill
Start Assist (HSA) feature. See Hill
Start Assist (HSA) on page 9‑52.
Adding non-dealer accessories can
affect the vehicle's performance.
See Accessories and Modifications
on page 10‑3.
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.

Black plate (60,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-60 Driving and Operating
Notice:If you use URPA while the
tailgate is lowered, it may not
detect an object behind your
vehicle, and you might back into
the object and damage your
vehicle. Always verify the tailgate
is closed when using URPA or
turn off URPA when driving with
the tailgate lowered.
When the System Does Not
Seem to Work Properly
The following messages may be
displayed on the DIC:
SERVICE PARK ASSIST: If this
message occurs, take the vehicle to
your dealer to repair the system.
PARK ASST BLOCKED SEE
OWNERS MANUAL: This
message can occur under the
following conditions:
.The ultrasonic sensors are not
clean. Keep the vehicle's rear
bumper free of mud, dirt, snow,
ice, and slush. For cleaning
instructions, see Exterior Care
on page 10‑91.
.The park assist sensors are
covered by frost or ice. Frost or
ice can form around and behind
the sensors and may not always
be seen; this can occur after
washing the vehicle in cold
weather. The message may not
clear until the frost or ice has
melted.
.A trailer was attached to the
vehicle, or an object was
hanging out of the tailgate during
the last drive cycle. Once the
object is removed and the
tailgate is raised, URPA will
return to normal operation.
.A tow bar is attached to the
vehicle.
.The bumper is damaged. Take
the vehicle to your dealer to
repair the system.
.Other conditions, such as
vibrations from a jackhammer or
the compression of air brakes on
a very large truck, are affecting
system performance.
Rear Vision
Camera (RVC)
If available, the Rear Vision Camera
(RVC) system displays part of the
scene behind the vehicle.
{WARNING
The RVC system does not display
children, pedestrians, bicyclists,
animals, or any other object
located outside the camera's field
of view, below the bumper,
or under the vehicle. Perceived
distances may be different from
actual distances. Do not back the
vehicle using only the RVC
screen, during longer, higher
speed backing maneuvers,
or where there could be cross
traffic. Failure to use proper care
before backing may result in
injury, death, or vehicle damage.
Always check behind and around
the vehicle before backing.

Black plate (66,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-66 Driving and Operating
Recommended Fuel
For all vehicles except those with
the 6.2L V8 engine (VIN Code 2),
use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving.
If this occurs, use a gasoline rated
at 87 octane or higher as soon as
possible. If heavy knocking is heard
when using gasoline rated at
87 octane or higher, the engine
needs service.
If the vehicle has the 6.2L V8 engine
(VIN Code 2), use premium
unleaded gasoline with a posted
octane rating of 91 or higher. You
can also use regular unleaded
gasoline rated at 87 octane or
higher, but the vehicle's acceleration
could be slightly reduced, and a
slight audible knocking noise,
commonly referred to as spark
knock, might be heard. If the octane
is less than 87, you might notice aheavy knocking noise when you
drive. If this occurs, use a gasoline
rated at 87 octane or higher as soon
as possible. Otherwise, you could
damage the engine. If heavy
knocking is heard when using
gasoline rated at 87 octane or
higher, the engine needs service.
Gasoline Specifications
At a minimum, gasoline should meet
ASTM specification D 4814. Some
gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. See
Fuel Additives
on page 9‑67.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog‐check test.
See
Malfunction Indicator Lamp on
page 5‑21. If this occurs, return to
your authorized dealer for diagnosis.
If it is determined that the condition
is caused by the type of fuel used,
repairs might not be covered by the
vehicle warranty.
Fuels in Foreign
Countries
Never use leaded gasoline or any
other fuel not recommended in the
previous text on fuel. Costly repairs
caused by use of improper fuel
would not be covered by the vehicle
warranty.

Black plate (71,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-71
Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10‑87.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10‑87.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
{WARNING
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
(Continued)
WARNING (Continued)
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control System”
in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9‑31.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the

Black plate (95,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-95
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for electric trailer brakes.
This symbol is located on the Trailer
Brake Control Panel on vehicles
with an Integrated Trailer Brake
Control system. The power output to
the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system. This available power output
to the trailer brakes can be adjusted
to a wide range of trailering
situations.
The ITBC system is integrated with
the vehicle’s brake, antilock brake,
and StabiliTrak (if equipped)
systems. In trailering conditions that cause the vehicle’s antilock brake or
StabiliTrak systems to activate,
power sent to the trailer's brakes will
be automatically adjusted to
minimize trailer wheel lock-up. This
does not imply that the trailer has
StabiliTrak.
The vehicle may have a Trailer
Sway Control (TSC) feature. See
Trailer Sway Control (TSC) on
page 9‑100.
The vehicle may have a Hill Start
Assist (HSA) feature. See
Hill Start
Assist (HSA) on page 9‑52.
If the vehicle’s brake, antilock brake,
or StabiliTrak systems are not
functioning properly, the ITBC
system may not be fully functional
or may not function at all. Make sure
all of these systems are fully
operational to ensure full
functionality of the ITBC system.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The ITBC system is fully functional only
when the ignition is in ON or
in RUN.
The ITBC system can only be used
with trailers with electric brakes.
{WARNING
Connecting a trailer that has a
surge, air,
or electric-over-hydraulic trailer
brake system may result in
reduced or complete loss of trailer
braking. There may be an
increase in stopping distance or
trailer instability which could
result in personal injury or
damage to the vehicle, trailer,
or other property. Use the ITBC
system only with electric brakes.

Black plate (100,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-100 Driving and Operating
If the CHECK TRAILER WIRING
message only re-appears when
connecting the trailer wiring
harness to the vehicle, the
electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will be
displayed when there is a problem
with the ITBC system. If this
message persists over multiple
ignition cycles, there is a problem
with the ITBC system. Take the
vehicle to an authorized GM dealer
to have the ITBC system diagnosed
and repaired.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message is
displayed while driving the vehicle, power is no longer available to the
trailer brakes. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
An authorized GM dealer may be
able to diagnose and repair
problems with the trailer. However,
any diagnosis and repair of the
trailer is not covered under the
vehicle warranty. Please contact
your trailer dealer for assistance
with trailer repairs and trailer
warranty information.Trailer Sway
Control (TSC)
Non-hybrid vehicles with StabiliTrak
have a Trailer Sway Control (TSC)
feature. If the vehicle is towing a
trailer and the system detects that
the trailer is swaying, the vehicle
brakes are applied without the driver
pressing the brake pedal. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, StabiliTrak may also
apply the trailer brakes. The TCS/
StabiliTrak warning light will flash on
the instrument panel cluster to notify
the driver to reduce speed. If the
trailer continues to sway, StabiliTrak
will reduce engine torque to help
slow the vehicle. See
StabiliTrak
®
System on page 9‑53 for more
information.
Adding non‐dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10‑3 for more information.