
Black plate (28,1)GMC Sierra Owner Manual - 2011
10-28 Vehicle Care
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage.
In this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe
place in an emergency. Driving
extended km (mi) and/or towing a
trailer in the overheat protection
mode should be avoided.
Notice:After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause
of coolant loss, change the oil
and reset the oil life system.
See Engine Oil on page 10‑7.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and
the clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing,
and/or high outside temperatures,
the fan speed increases as the
clutch more fully engages, so an
increase in fan noise may be heard.
This is normal and should not be
mistaken as the transmission
slipping or making extra shifts.
It is merely the cooling system
functioning properly. The fan will
slow down when additional cooling
is not required and the clutch
disengages. This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during
most everyday driving. The fans
may turn off if no cooling is required.
Under heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.
The fans will change to low speed
when additional cooling is no
longer required.

Black plate (103,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-103
Towing
Towing the Vehicle
Notice:To avoid damage,
the disabled vehicle should be
towed with all four wheels off
the ground. Care must be taken
with vehicles that have low
ground clearance and/or special
equipment. Always flatbed on a
car carrier.
Consult your dealer or a
professional towing service if the
disabled vehicle must be towed.
See Roadside Assistance Program
(U.S. and Canada) on page 13‑8
or Roadside Assistance Program
(Mexico) on page 13‑10.
To tow the vehicle behind another
vehicle for recreational purposes,
such as behind a motor home, see
“Recreational Vehicle Towing” in this
section.
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home.
The two most common types of
recreational vehicle towing are
known as dinghy towing and dolly
towing. Dinghy towing is towing the
vehicle with all four wheels on the
ground. Dolly towing is towing the
vehicle with two wheels on the
ground and two wheels up on a
device known as a dolly.
Here are some important things to
consider before recreational vehicle
towing:
.What is the towing capacity
of the towing vehicle?
Be sure to read the tow
vehicle manufacturer's
recommendations.
.What is the distance that will be
travelled? Some vehicles have
restrictions on how far and how
long they can tow.
.Is the proper towing equipment
going to be used? See your
dealer or trailering professional
for additional advice and
equipment recommendations.
.Is the vehicle ready to be
towed? Just as preparing the
vehicle for a long trip, make sure
the vehicle is prepared to be
towed.

Black plate (104,1)GMC Sierra Owner Manual - 2011
10-104 Vehicle Care
Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If the vehicle is
towed with all four wheels
on the ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty. Do not
tow the vehicle with all four
wheels on the ground. Two-wheel-drive vehicles should
not be towed with all four wheels
on the ground. Two-wheel-drive
transmissions have no provisions
for internal lubrication while being
towed.
Four-Wheel-Drive Vehicles
Use the following procedure to
dinghy tow a four-wheel-drive
vehicle:
1. Position the vehicle being towed
behind the tow vehicle and shift
the transmission to P (Park). 2. Turn the engine off and firmly set
the parking brake.
3. Securely attach the vehicle being towed to the tow vehicle.
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
4. Shift the transfer case to N (Neutral). See “Shifting into
Neutral” underFour-Wheel Drive
on page 9‑54 for the proper
procedure to select the Neutral
position for the vehicle.

Black plate (105,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-105
5. Release the parking brake onlyafter the vehicle being towed is
firmly attached to the towing
vehicle.
6. Turn the ignition to LOCK/OFF and remove the key —the
steering wheel will still turn.
After towing, see “Shifting Out of
Neutral” underFour-Wheel Drive on
page 9‑54 for the proper procedure
to take the vehicle out of the Neutral
position.Dolly Towing
Front Towing (Front Wheels Off
the Ground) –Two-Wheel-Drive
Vehicles
Notice: If a two-wheel-drive
vehicle is towed with the rear
wheels on the ground, the transmission could be damaged.
The repairs would not be covered
by the vehicle warranty. Never
tow the vehicle with the rear
wheels on the ground.
Two-wheel-drive vehicles should
not be towed with the rear wheels
on the ground. Two-wheel-drive
transmissions have no provisions
for internal lubrication while being
towed.
To dolly tow a two‐wheel‐drive
vehicle, the vehicle must be towed
with the rear wheels on the dolly.
See
“Rear Towing (Rear Wheels Off
the Ground)” later in this section for
more information.

Black plate (106,1)GMC Sierra Owner Manual - 2011
10-106 Vehicle Care
Front Towing (Front Wheels Off
the Ground)–Four-Wheel-Drive
Vehicles
Use the following procedure to dolly
tow a four-wheel-drive vehicle from
the front:
1. Attach the dolly to the tow
vehicle following the dolly
manufacturer's instructions.
2. Drive the front wheels onto the dolly. 3. Shift the transmission to
P (Park).
4. Firmly set the parking brake.
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
5. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position. 6. Secure the vehicle to the dolly
following the manufacturer's
instructions.
7. Shift the transfer case to N (Neutral). See “Shifting into
Neutral” underFour-Wheel Drive
on page 9‑54 for the proper
procedure to select the neutral
position for the vehicle.
8. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
9. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
Neutral” underFour-Wheel Drive on
page 9‑54.

Black plate (107,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-107
Rear Towing (Rear Wheels
Off the Ground)
Two‐Wheel‐Drive Vehicles
Use the following procedure to dolly
tow a two-wheel-drive vehicle from
the rear:
1. Attach the dolly to the towvehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly. 3. Firmly set the parking brake.
See Parking Brake on
page 9‑69.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.
6. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.
7. Turn the ignition to LOCK/OFF. Four‐Wheel‐Drive Vehicles
Use the following procedure to dolly
tow a four-wheel-drive vehicle from
the rear:
1. Attach the dolly to the tow
vehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. See Parking Brake on
page 9‑69.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.

Black plate (108,1)GMC Sierra Owner Manual - 2011
10-108 Vehicle Care
6. Use an adequate clampingdevice designed for towing to
ensure that the front wheels are
locked into the straight position.
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
7. Shift the transfer case to N (Neutral). See “Shifting into
Neutral” underFour-Wheel Drive
on page 9‑54 for the proper
procedure to select the neutral
position for the vehicle.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
Neutral” underFour-Wheel Drive on
page 9‑54.
Appearance Care
Exterior Care
Silicone grease on weatherstrips
will make them last longer, seal
better, and not stick or squeak.
Apply silicone grease with a clean
cloth. During very cold, damp
weather frequent application may
be required. See Recommended
Fluids and Lubricants on page 11‑8.
Washing the Vehicle
The best way to preserve the
vehicle's finish is to keep it clean
by washing it often.
Notice: Certain cleaners contain
chemicals that can damage the
emblems or nameplates on the
vehicle. Check the cleaning
product label. If it states that it
should not be used on plastic
parts, do not use it on the vehicle
or damage may occur and it
would not be covered by the
warranty. Do not wash the vehicle in direct
sunlight. Use a car washing soap.
Do not use cleaning agents that
are petroleum based or that contain
acid or abrasives, as they can
damage the paint, metal or plastic
on the vehicle. Approved cleaning
products can be obtained from your
dealer. Follow all manufacturers'
directions regarding correct
product usage, necessary safety
precautions and appropriate
disposal of any vehicle care
product.
Rinse the vehicle well, before
washing and after to remove all
cleaning agents completely. If they
are allowed to dry on the surface,
they could stain.
Dry the finish with a soft, clean
chamois or an all-cotton towel to
avoid surface scratches and water
spotting.

Black plate (6,1)GMC Sierra Owner Manual - 2011
11-6 Service and Maintenance
First Engine Oil Change After
Every 40 000 km/25,000 Miles
.Four‐wheel drive only: Transfer
case fluid change (extreme duty
service) for vehicles mainly
driven off‐road in four‐wheel
drive. Vehicles used for farming,
mining, forestry, Department of
Natural Resources (DNR), and
snow plowing occupations meet
this definition. Check vent hose
at transfer case for kinks and
proper installation. Check to be
sure vent hose is unobstructed,
clear, and free of debris. During
any maintenance, if a power
washer is used to clean mud
and dirt from the underbody,
care should be taken to not
directly spray the transfer case
output seals. High pressure
water can overcome the seals
and contaminate the transfer
case fluid. Contaminated fluid
will decrease the life of the
transfer case and should be
replaced.First Engine Oil Change After
Every 80 000 km/50,000 Miles.Engine air cleaner filter
replacement. See
Engine Air
Cleaner/Filter on page 10‑19.
.Automatic transmission fluid
change (severe service) for
vehicles with Gross Vehicle
Weight Rating (GVWR) over
3 901 kg (8,600 lbs) or mainly
driven in heavy city traffic in hot
weather, in hilly or mountainous
terrain, when frequently towing
a trailer, or used for taxi,
police, or delivery service.
See Automatic Transmission
Fluid (4-Speed Transmission) on
page 10‑13 orAutomatic
Transmission Fluid (6-Speed
Transmission) on page 10‑16.
.Four‐wheel drive only: Transfer
case fluid change (severe
service) for vehicles mainly
driven when frequently towing
a trailer, or used for taxi, police,
or delivery service. Check
vent hose at transfer case for
kinks and proper installation.
Check to be sure vent hose is
unobstructed, clear, and free of
debris. During any maintenance,
if a power washer is used to
clean mud and dirt from the
underbody, care should be taken
to not directly spray the transfer
case output seals. High pressure
water can overcome the seals
and contaminate the transfer
case fluid. Contaminated fluid
will decrease the life of the
transfer case and should be
replaced.