2013 GMC SIERRA light

Black plate (8,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-8 Driving and Operating
{WARNING
If the vehicle has the two‐speed
automatic transfer case, shifting
the transfer case to N (Neutral)
can cause your vehicle to roll
even if the transmission is in
P (Park). This is because the
N (Neutral) position on the
transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
.When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
{WARNING
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill:
1. Apply the brakes to stop the vehicle, and then apply the
parking brake.
2. Shift into P (Park) and then restart the engine.
.If driving uphill when the
vehicle stalls, shift to
R (Reverse), release the
parking brake, and back
straight down.
.Never try to turn the vehicle
around. If the hill is steep
enough to stall the vehicle,
it is steep enough to cause
it to roll over.
.If you cannot make it up the
hill, back straight down
the hill.
.Never back down a hill in
N (Neutral) using only the
brake.
.The vehicle can roll
backward quickly and you
could lose control.
.If driving downhill when the
vehicle stalls, shift to a
lower gear, release the
parking brake, and drive
straight down the hill.
3. If the vehicle cannot be restarted after stalling, set the parking
brake, shift an automatic
transmission into P (Park), and
turn the vehicle off.
3.1. Leave the vehicle and seek help.

Black plate (10,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-10 Driving and Operating
Driving in Water
{WARNING
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires.
Traction could be lost, and the
vehicle could roll over. Do not
drive through rushing water.
Notice: Do not drive through
standing water if it is deep
enough to cover the wheel hubs,
axles or exhaust pipe. Deep water
can damage the axle and other
vehicle parts.
If the standing water is not too deep,
drive slowly through it. At faster
speeds, water splashes on the
ignition system and the vehicle can
stall. Stalling can also occur if you
get the tailpipe under water. While the tailpipe is under water, you will
not be able to start the engine.
When going through water, the
brakes get wet, and it might take
longer to stop. See Driving on Wet
Roads.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
or chassis, or under the hood.
These accumulations can be a fire
hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. Refer to the
Maintenance Schedule for more
information.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep‐standing or flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
(Continued)

Black plate (13,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-13
Blizzard Conditions
Being stuck in snow can be a
serious situation. Stay with the
vehicle unless there is help nearby.
If possible, use Roadside
Assistance. SeeRoadside
Assistance Program (Mexico) on
page 13‑7 orRoadside Assistance
Program (U.S. and Canada) on
page 13‑11. To get help and keep
everyone in the vehicle safe:
.Turn on the hazard warning
flashers.
.Tie a red cloth to an outside
mirror.
{WARNING
Snow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO) which
(Continued)
WARNING (Continued)
cannot be seen or smelled. It can
cause unconsciousness and even
death.
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about 5 cm
(2 in) on the side of the
vehicle that is away from the
wind to bring in fresh air.
.Fully open the air outlets on
or under the instrument
panel.
.Adjust the climate control
system to a setting that
circulates the air inside the
vehicle and set the fan speed(Continued)
WARNING (Continued)
to the highest setting. See
“Climate Control Systems” in
the Index.
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑31.
To save fuel, run the engine for only
short periods as needed to warm
the vehicle and then shut the engine
off and close the window most of
the way to save heat. Repeat this
until help arrives but only when you
feel really uncomfortable from the
cold. Moving about to keep warm
also helps.
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine runs
faster than the idle speed. This
keeps the battery charged to restart
the vehicle and to signal for help
with the headlamps. Do this as little
as possible to save fuel.

Black plate (14,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-14 Driving and Operating
If the Vehicle Is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
See“Rocking Your Vehicle to Get It
Out”later in this section.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle's
traction system in the Index. If stuck
too severely for the traction system
to free the vehicle, turn the traction
system off and use the rocking
method.
{WARNING
If the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 56 km/h (35 mph). For information about using tire
chains on the vehicle, see
Tire
Chains on page 10‑70.
Rocking Your Vehicle to Get
It Out
Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four-Wheel High.
For vehicles with StabiliTrak
®, turn
the traction control part of the
system off. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal while
shifting, and press lightly on the
accelerator pedal when the
transmission is in gear. Slowly spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the
vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. Recovery
hooks can be used, if the vehicle
has them. If the vehicle does need
to be towed out, see
Towing the
Vehicle on page 10‑87.Recovery Hooks
{WARNING
Never pull on recovery hooks
from the side. The hooks could
break and you and others could
be injured. When using recovery
hooks, always pull the vehicle
from the front.

Black plate (25,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-25
{WARNING
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
turn the ignition to ACC/
ACCESSORY.
Notice: Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer.
B (ACC/ACCESSORY): This
position lets things like the radio
and the windshield wipers operate while the engine is off. Use this
position if the vehicle must be
pushed or towed.
C (ON/RUN):
This position can be
used to operate the electrical
accessories and to display some
instrument panel cluster warning
and indicator lights. This position
can also be used for service and
diagnostics, and to verify the proper
operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position
when the engine is running. The
transmission is also unlocked in this
position on automatic transmission
vehicles.
If you leave the key in the ACC/
ACCESSORY or ON/RUN position
with the engine off, the battery could
be drained. You may not be able to
start the vehicle if the battery is
allowed to drain for an extended
period of time. D (START):
This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.
A warning tone will sound when the
driver door is opened and the
ignition is in ACC/ACCESSORY or
LOCK/OFF, and the key is in the
ignition.
Starting the Engine
If the vehicle has a diesel engine,
see the Duramax®diesel
supplement for more information.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Notice: Do not try to shift to
P (Park) if the vehicle is moving.
If you do, you could damage the
transmission. Shift to P (Park)
only when the vehicle is stopped.

Black plate (27,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-27
If the vehicle starts briefly but
then stops again, do the same
thing. This clears the extra
gasoline from the engine. Do not
race the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts.
Fast Idle System
If the vehicle has this feature it is
available only with cruise control.
The manual fast idle switch is
operated using the cruise control
buttons located on the left hand side
of the steering wheel.
This system can be used to
increase engine idle speed
whenever the following conditions
are met:
.The parking brake is set.
.The brake pedal is not pressed.
.The vehicle must not be moving
and the accelerator must not be
pressed.To control the fast idle:
.To enable the Fast Idle System,
press and release the cruise
control on/off button and ensure
that the switch indicator light
is lit.
.Press and release the cruise
control SET-button. Engine
speed will be held at
approximately 1200 RPM.
When the fast idle is active the
Driver Information Center (DIC) will
display “FAST IDLE ON.”
One of the following actions will turn
off the fast idle:
.Pressing the brake.
.Selecting the cruise control
cancel button.
.Releasing the parking brake.
.The transmission shift lever is
moved out of P (Park) or
N (Neutral).
.Selecting the cruise control on/
off button when it was
previously on.
.Pressing the cruise control
SET-button a second time.
.Pressing the accelerator greater
than a quarter of the way down.
.Turning the ignition switch to the
LOCK/OFF position.
Retained Accessory
Power (RAP)
The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.Audio System
.Power Windows
.OnStar System (if equipped)
.Sunroof (if equipped)
These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened.

Black plate (32,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-32 Driving and Operating
Running the Vehicle
While Parked
It is better not to park with the
engine running.
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
SeeShifting Into Park on page 9‑28
and Engine Exhaust on page 9‑31.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑71.
Automatic
Transmission
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Vehicles with an automatic
transmission have an electronic shift
position indicator within the
instrument panel cluster. This
display comes on when the ignition
key is turned to the ON/RUN
position.
There are several different positions
for the shift lever.
Hydra-Matic®4-Speed Automatic
Transmission
Heavy Duty 6-Speed Automatic
Transmission Shown (Light Duty 6-Speed Similar)
See “Range Selection Mode” under
Manual Mode on page 9‑36.
P (Park): This position locks the
rear wheels. It is the best position to
use when starting the engine
because the vehicle cannot move
easily. When parked on a hill,

Black plate (37,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-37
Low Traction Mode
If the vehicle has the Allison
Transmission, a 4-Speed automatic
transmission, or the Hydra-Matic
6-Speed Automatic Transmission
with the 6.0L engine, it has a Low
Traction Mode that assists in vehicle
acceleration when road conditions
are slippery, such as with ice or
snow. While the vehicle is at a stop,
select the second gear range using
Range Selection Mode. This will
limit torque to the wheels helping to
prevent the tires from spinning.
Tow/Haul Mode
4-Speed Automatic Transmission
6-Speed Automatic Transmission
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when driving down steep hills or
Mountain grades, towing, or hauling
heavy loads.
The selector button is located on the
end of the shift lever. Turn the Tow/
Haul Mode on and off by pressing
the button. When the Tow/Haul
Mode is enabled, a light on the
instrument panel cluster will
come on. See
Tow/Haul Mode Light on
page 5‑25 andHill and Mountain
Roads on page 9‑11 for more
information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑89 for
more information.
Tow/Haul Mode Grade Braking
(6-Speed Automatic
Transmission)
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9‑36. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle.