2011 GMC SIERRA 1500 brake

Black plate (78,1)GMC Sierra Owner Manual - 2011
9-78 Driving and Operating
.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 a bicycle or an object
was hanging out of the tailgate
during the last drive cycle. Once
the attached object is removed
and the tailgate is raised, URPA
will return to normal operation.
.A tow bar is attached to the
vehicle.
.The vehicle's bumper is
damaged. Take the vehicle to
your dealer to repair the system.
.Other conditions are affecting
system performance. Examples
of this are vibrations from a
jackhammer or the compression
of air brakes on a very large
truck.
Rear Vision
Camera (RVC)
This vehicle may have a Rear
Vision Camera (RVC) system. Read
this entire section before using it.
{WARNING
The Rear Vision Camera (RVC)
system does not replace driver
vision. RVC does not:
.Detect objects that are
outside the camera's field
of view, below the bumper,
or underneath the vehicle.
.Detect children, pedestrians,
bicyclists, or pets.
Do not back the vehicle by only
looking at the RVC screen, or use
the screen during longer, higher (Continued)
WARNING (Continued)
speed backing maneuvers or
where there could be cross-traffic.
Your judged distances using the
screen will differ from actual
distances.
If you do not use proper care
before backing up, you could
hit a vehicle, child, pedestrian,
bicyclist, or pet, resulting in
vehicle damage, injury, or death.
Even though the vehicle has
the RVC system, always check
carefully before backing up by
checking behind and around the
vehicle.

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 (94,1)GMC Sierra Owner Manual - 2011
9-94 Driving and Operating
To avoid this, let the engine
run while parked, preferably on
level ground, with the automatic
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating on
page 10‑25.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but
do not shift into P (Park) yet.
Turn the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. If the vehicle is four-wheel-drive, be sure the transfer case is in a
drive gear and not in N (Neutral).
6. Release the brake pedal.
{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 the engine has been left
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when on fairly
level ground, use the steps that
follow.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set.
If the transfer case on a
four-wheel-drive vehicle is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
case is in a drive gear —not in
N (Neutral).

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 (114,1)GMC Sierra Owner Manual - 2011
9-114 Driving and Operating
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lbs) needs to
have its own brake system that
is adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted, and
maintained properly.
If the vehicle is equipped with
StabiliTrak, the trailer cannot tap
into the vehicle's hydraulic brake
system.
The trailer brake system can tap
into the vehicle's hydraulic brake
system only if:
.The trailer parts can withstand
20 650 kPa (3,000 psi) of
pressure.
.The trailer's brake system
will use less than 0.3 cc
(0.02 cubic inch) of fluid from
the vehicle's master cylinder.
Otherwise, both braking systems
will not work well or at all.If everything checks out this far,
make the brake tap at the port on
the master cylinder that sends the
fluid to the rear brakes. Use only
steel brake tubing to make the tap.
Auxiliary Battery
The auxiliary battery provision can
be used to supply electrical power
to additional equipment that may be
added, such as a slide-in camper.
If the vehicle has this provision,
this relay will be located on the
driver side of the vehicle, next to
the underhood electrical center.
Be sure to follow the proper
installation instructions included
with any electrical equipment that
is installed.
Notice:
Leaving electrical
equipment on for extended
periods will drain the battery.
Always turn off electrical
equipment when not in use
and do not use equipment that
exceeds the maximum amperage
rating for the auxiliary battery
provision.
Trailer Wiring Harness
The vehicle is equipped with one of
the following wiring harnesses for
towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew
cab pickups have a seven‐wire
trailer towing harness.
For vehicles not equipped with
heavy duty trailering, the harness
is secured to the vehicle's frame
behind the spare tire mount.
The harness requires the installation
of a trailer connector, which is
available through your dealer.
If towing a light‐duty trailer with
a standard four‐way round pin
connector, an adapter is available
from your dealer.

Black plate (115,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-115
Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy
duty trailering, the harness is
connected to a bracket on the hitch
platform. The seven-wire harness
contains the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits
are installed in the underhood
electrical center, but the wires are
not connected. They should be
connected by your dealer or a
qualified service center. The fuse
and wire for the ITBC is factory
installed and connected if the
vehicle is equipped with an ITBC.
The fuse for the battery feed is
not required if the vehicle has an
auxiliary battery. If the vehicle does
not have an auxiliary battery, have
your dealer or authorized service
center install the required fuse. If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, located at
the end of the shift lever. This will
boost the vehicle system voltage
and properly charge the battery.
If the trailer is too light for Tow/
Haul Mode, or the vehicle is not
equipped with Tow/Haul, turn on
the headlamps as a second way
to boost the vehicle system and
charge the battery.

Black plate (116,1)GMC Sierra Owner Manual - 2011
9-116 Driving and Operating
Camper/Fifth-Wheel Trailer Wiring
Package
The seven-wire camper harness
is located under the front edge of
the pickup box on the driver side
of the vehicle, attached to the
frame bracket. A connector must
be added to the wiring harness
which connects to the camper.
The harness contains the following
camper/trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed
.Dark Blue: Trailer Brake
If the vehicle is equipped with the
“Heavy-Duty Trailering”option,
please refer to “Heavy-Duty Trailer
Wiring Package” earlier in this
section.
When the camper-wiring harness
is ordered without the heavy-duty
trailering package, an eight-wire
harness with a seven-pin connector
is located at the rear of the vehicle
and is tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part
of the trailer wiring package. These
provisions are for an electric brake
controller. The instrument panel
contains blunt cut wires behind the
steering column for the trailer brake
controller. The harness contains the
following wires:
.Dark Blue: Brake Signal to
Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
The harness should be installed by
your dealer or a qualified service
center.