2011 GMC SIERRA towing

Black plate (64,1)GMC Sierra Owner Manual - 2011
9-64 Driving and Operating
AUTO (Automatic Four-Wheel
Drive):This setting is ideal for
use when road surface traction
conditions are variable. When
driving the vehicle in AUTO,
the front axle is engaged, but the
vehicle's power is sent only to the
front and rear wheels automatically
based on driving conditions. Driving
in this mode results in slightly lower
fuel economy than Two-Wheel
Drive High.
4
m(Four-Wheel Drive High): Use
the Four-Wheel Drive High position
when extra traction is needed, such
as on snowy or icy roads or in most
off-road situations. This setting also
engages the front axle to help drive
the vehicle. This is the best setting
to use when plowing snow. 4
n(Four-Wheel Drive Low):
This
setting also engages the front axle
and delivers extra torque. You may
never need this setting. It sends
maximum power to all four wheels.
You might choose Four-Wheel Drive
Low if you are driving off-road in
deep sand, deep mud, deep snow,
and while climbing or descending
steep hills.
If the vehicle has StabiliTrak
®,
shifting into Four-Wheel Drive
Low will turn Traction Control and
StabiliTrak off. See StabiliTrak
®
System on page 9‑70.
{WARNING
Shifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission
is in P (Park). You or someone
else could be seriously injured.
Be sure to set the parking brake
before placing the transfer case in
N (Neutral). SeeParking Brake on
page 9‑69. N (Neutral):
Shift the vehicle's
transfer case to N (Neutral)
only when towing the vehicle.
See Recreational Vehicle Towing on
page 10‑103 orTowing the Vehicle
on page 10‑103 for more
information.
If the SERVICE 4 WHEEL DRIVE
message stays on, you should
take the vehicle to your dealer for
service. See “SERVICE 4 WHEEL
DRIVE message” under
Transmission Messages on
page 5‑50.
Shifting Into Four-Wheel Drive
High or AUTO (Automatic
Four-Wheel Drive)
Turn the knob to the Four-Wheel
Drive High or AUTO position. This
can be done at any speed, except
when shifting from Four-Wheel
Drive Low. The indicator light will
flash while shifting. It will remain
on when the shift is completed.

Black plate (69,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-69
Braking in Emergencies
ABS allows the driver to steer and
brake at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
Set the parking brake by holding
the regular brake pedal down, then
pushing down the parking brake
pedal.If the ignition is on, the brake
system warning light will come on.
See
Brake System Warning Light on
page 5‑27.
Notice: Driving with the parking
brake on can overheat the brake
system and cause premature
wear or damage to brake system
parts. Make sure that the parking
brake is fully released and the
brake warning light is off before
driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will flash and a
chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and
are parking on a hill, see Driving
Characteristics and Towing Tips on
page 9‑91.
Brake Assist (Except
With 4.3L V6 Engine)
If this vehicle has StabiliTrak®, it
also has a Brake Assist feature
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement
the power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle.
The stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.

Black plate (90,1)GMC Sierra Owner Manual - 2011
9-90 Driving and Operating
Filling a Portable Fuel
Container
{WARNING
Never fill a portable fuel container
while it is in the vehicle. Static
electricity discharge from the
container can ignite the fuel
vapor. You can be badly burned
and the vehicle damaged if this
occurs. To help avoid injury to
you and others:
.Dispense fuel only into
approved containers.
.Do not fill a container while
it is inside a vehicle, in a
vehicle's trunk, pickup bed,
or on any surface other than
the ground.(Continued)
WARNING (Continued)
.Bring the fill nozzle in contact
with the inside of the fill
opening before operating
the nozzle. Contact should
be maintained until the filling
is complete.
.Do not smoke while
pumping fuel.
.Do not use a cellular phone
while pumping fuel.
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.
See the following trailer towing
information in this section:
.For information on driving
while towing a trailer, see
“Driving Characteristics and
Towing Tips.”
.For maximum vehicle and trailer
weights, see“Trailer Towing.”
.For information on equipment
to tow a trailer, see “Towing
Equipment.”

Black plate (91,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-91
For information on towing a disabled
vehicle, seeTowing the Vehicle on
page 10‑103. For information on
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing on
page 10‑103.
Driving Characteristics
and Towing Tips
Pulling a Trailer
Important points for pulling a trailer:
.There are many different laws,
including speed limit restrictions,
having to do with trailering.
Make sure the rig will be legal,
not only where you live but
also where you will be driving.
A good source for this
information can be state
or provincial police.
.Consider using a sway control.
See “Hitches” underTowing
Equipment on page 9‑112.
.Do not tow a trailer at all during
the first 800 km (500 miles)
the new vehicle is driven.
The engine, axle, or other
parts could be damaged.
.During the first 800 km
(500 miles) that a trailer is
towed, do not drive over
80 km/h (50 mph) and do
not make starts at full throttle.
This helps the engine and other
parts of the vehicle wear in at
the heavier loads.
.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.
Important considerations that have
to do with weight:
.Weight of the trailer
.Weight of the trailer tongue
.Weight on the vehicle's tires
.Weight of the trailering
combination

Black plate (92,1)GMC Sierra Owner Manual - 2011
9-92 Driving and Operating
Driving with a Trailer
{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.
Engine exhaust contains Carbon
Monoxide (CO) which cannot be
seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing
a trailer:
.Have the exhaust system
inspected for leaks and make
necessary repairs before
starting a trip.
.Never 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.
.Adjust the Climate Control
system to a setting that
brings in only outside air
and set the fan speed to the
highest setting. See Climate
Control System in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9‑44.
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
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.

Black plate (93,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-93
Passing
More passing distance is
needed when towing a trailer.
The combination will not accelerate
as quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand
to the left. To move the trailer to
the right, move your hand to the
right. Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with
the vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer,
make wider turns than normal.
Do this so the trailer will not strike
soft shoulders, curbs, road signs,
trees, or other objects. Avoid jerky
or sudden maneuvers. Signal well
in advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
panel will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a
lower gear beforestarting down
a long or steep downgrade. If the
transmission is not shifted down,
the brakes might get hot and no
longer work well.
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.
The Tow/Haul Mode may be used
if the transmission shifts too often.
See Tow/Haul Mode on page 9‑51.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil
at a lower temperature than at
normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show
signs similar to engine overheating.

Black plate (95,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-95
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer isclear of the chocks.
7. Stop and have someone pick up
and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See this
manual's Maintenance Schedule
or Index for more information.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system,
and brake system. It is a good
idea to inspect these before
and during the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
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.
Do not tow a trailer during break‐in.
See New Vehicle Break-In on
page 9‑34 for more information.
{WARNING
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly.
For example, if the trailer is too
heavy, the brakes may not work
well or even at all. The driver and
passengers could be seriously
injured. The vehicle may also be
damaged; the resulting repairs
would not be covered by the
(Continued)
WARNING (Continued)
vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
Notice: Pulling a trailer
improperly can damage the
vehicle and result in costly
repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” later in this
section.

Black plate (112,1)GMC Sierra Owner Manual - 2011
9-112 Driving and Operating
Weight of the Trailering
Combination
It is important that the combination
of the tow vehicle and trailer
does not exceed any of its weight
ratings—GCWR, GVWR, RGAWR,
Trailer Weight Rating, or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings
is to weigh the tow vehicle and
trailer combination, fully loaded for
the trip, getting individual weights
for each of these items.
Towing Equipment
Hitches
The correct hitch equipment helps
maintain combination control.
Most small-to-medium trailers can
be towed with a weight-carrying
hitch which simply features a
coupler latched to the hitch ball. Larger trailers may require a
weight-distributing hitch that
uses spring bars to distribute
the trailer tongue weight among
the two vehicle and trailer axles.
Fifth-wheel and gooseneck hitches
may also be used. See
“Weight of
the Trailer Tongue” underTrailer
Towing on page 9‑95 for rating
limits with various hitch types.
If a step-bumper hitch will be used,
the bumper could be damaged
in sharp turns. Make sure there
is ample room when turning to
avoid contact between the trailer
and the bumper.
Consider using sway controls
with any trailer. Ask a trailering
professional about sway controls
or refer to the trailer manufacturer's
recommendations and instructions.
Weight‐Distributing Hitch
Adjustment
A. Body to Ground Distance
B. Front of Vehicle
When using a weight-distributing
hitch, the spring bars should be
adjusted so the distance (A) is the
same after coupling the trailer to the
tow vehicle and adjusting the hitch.