ECU GMC SIERRA 1500 2011 Workshop Manual

Black plate (9,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-9
WARNING (Continued)
.Heavy loads on the roof raise
the vehicle's center of gravity,
making it more likely to roll
over. You can be seriously or
fatally injured if the vehicle
rolls over. Put heavy loads
inside the cargo area, not on
the roof. Keep cargo in the
cargo area as far forward
and low as possible.
There are some important things to
remember about how to load your
vehicle.
.The heaviest things should be
on the floor, forward of the rear
axle. Put heavier items as far
forward as you can.
.Be sure the load is properly
secured, so things are not
tossed around.
You will find other important
information under Vehicle Load
Limits on page 9‑25 andTires on
page 10‑57.
Environmental Concerns
Off-road driving can provide
wholesome and satisfying
recreation. However, it also
raises environmental concerns.
We recognize these concerns
and urge every off-roader to follow
these basic rules for protecting
the environment:
.Always use established trails,
roads, and areas that have been
specially set aside for public
off-road recreational driving and
obey all posted regulations.
.Avoid any driving practice
that could damage shrubs,
flowers, trees, or grasses or
disturb wildlife. This includes
wheel-spinning, breaking down
trees, or unnecessary driving
through streams or over soft
ground.
.Always carry a litter bag and
make sure all refuse is removed
from any campsite before
leaving.
.Take extreme care with open
fires (where permitted), camp
stoves, and lanterns.
.Never park your vehicle over
dry grass or other combustible
materials that could catch fire
from the heat of the vehicle's
exhaust system.

Black plate (29,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-29
Never exceed the GVWR for
your vehicle, or the GAWR for
either the front or rear axle.
The Certification/Tire label also
contains important information
about your Front Axle Reserve
Capacity. See“What is front axle
reserve capacity, and how do I
calculate it?” underAdding a
Snow Plow or Similar Equipment
on page 9‑125.
{WARNING
In the case of a sudden stop
or collision, things carried in
the bed of your truck could
shift forward and come into
the passenger area, injuring
you and others. If you put
things in the bed of your truck,
you should make sure they
are properly secured.
{WARNING
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
This can cause systems to
break and change the way the
vehicle handles. This could
cause loss of control and a
crash. Overloading can also
shorten the life of the vehicle. Notice :
Overloading the
vehicle may cause damage.
Repairs would not be covered
by the vehicle warranty.
Do not overload the vehicle.
Using heavier suspension
components to get added
durability might not change
your weight ratings. Ask your
dealer to help you load your
vehicle the right way.

Black plate (30,1)GMC Sierra Owner Manual - 2011
9-30 Driving and Operating
If you put things inside your
vehicle—like suitcases,
tools, packages, or anything
else —they go as fast as the
vehicle goes. If you have to
stop or turn quickly, or if there
is a crash, they will keep going.
{WARNING
Things you put inside the
vehicle can strike and injure
people in a sudden stop or
turn, or in a crash.
.Put things in the cargo
area of the vehicle. Try to
spread the weight evenly.
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
(Continued)
WARNING (Continued)
.Do not leave an
unsecured child restraint
in the vehicle.
.When you carry something
inside the vehicle, secure
it whenever you can.
.Do not leave a seat folded
down unless you need to.
There is also important loading
information for off-road driving in
this manual. See “Loading Your
Vehicle for Off-Road Driving“
under Off-Road Driving on
page 9‑7. Two-Tiered Loading
Depending on the model of your
pick‐up, an upper load platform
can be created by positioning
three or four 5 cm (2 inches) by
15 cm (6 inches) wooden planks
across the width of the pickup
box. The planks must be
inserted in the pickup box
depressions.
When using this upper load
platform, be sure the load is
securely tied down to prevent it
from shifting. The load's center
of gravity should be positioned
in a zone over the rear axle.
The zone is located in the area
between the front of each wheel
well and the rear of each wheel
well. The center of gravity height
must not extend above the top
of the pickup box flareboard.

Black plate (33,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-33
Here is an example of proper
truck and camper match:
A.Camper Center of Gravity
B.Recommended Center of
Gravity Location ZoneWhen the truck is used to carry
a slide‐in camper, the total cargo
load of the truck consists of the
manufacturer's camper weight
figure, the weight of installed
additional camper equipment not
included in the manufacturer's
camper weight figure, the weight
of camper cargo, and the weight
of passengers in the camper.
The total cargo load should
not exceed the truck's cargo
weight rating, and the camper's
center of gravity (A) should fall
within the truck's recommended
center of gravity zone (B) when
installed.
Any accessories or other
equipment that are added to
the vehicle must be weighed.
Then, subtract this extra weight
from the CWR. This extra weight
may shorten the center of
gravity zone of the vehicle.
If the slide-in camper and its
load weighs less than the CWR,
the center of gravity zone for
your vehicle may be larger.
Secure loose items to prevent
weight shifts that could affect
the balance of the vehicle.

Black plate (40,1)GMC Sierra Owner Manual - 2011
9-40 Driving and Operating
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.
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.
(Continued)

Black plate (82,1)GMC Sierra Owner Manual - 2011
9-82 Driving and Operating
Disconnecting the Rear Vision
Camera
The rear vision camera must be
disconnected if the tailgate needs
to be removed.
To disconnect the camera:
1. Remove the license plate.
2. Disconnect the cameraconnectors from the chassis
harness, located behind the
license plate, by pressing on the
release tab on each connector.
A. Chassis harness connector
B. Release tab
C. Camera connector
3. Plug the two exposed chassis harness connectors together to
prevent contamination.A. Chassis harness connector
B. Release tab
4. Feed the wiring harness through the pickup box, then plug the
camera connectors together
to prevent contamination.
5. Remove the tailgate. See Tailgate on page 2‑10
for more information.
6. Reinstall the license plate.
Reverse this procedure to reinstall
the rear vision camera and make
sure the grommet and connection
are secure.

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 (110,1)GMC Sierra Owner Manual - 2011
9-110 Driving and Operating
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices.
SeeCustomer Assistance Offices
(U.S. and Canada) on page 13‑5
or Customer Assistance Offices
(Mexico) on page 13‑5 for more
information.
Weight of the Trailer Tongue
The tongue load (A) of any
trailer is very important because
it is also part of the vehicle weight.
The Gross Vehicle Weight (GVW)
includes the curb weight of the vehicle, any cargo carried in it, and
the people who will be riding in the
vehicle as well as trailer tongue
weight. Vehicle options, equipment,
passengers and cargo in the vehicle
reduce the amount of tongue weight
the vehicle can carry, which will also
reduce the trailer weight the vehicle
can tow. See
“Vehicle Load Limits”
for more information about the
vehicle's maximum load capacity.
Trailer tongue weight (A) should be
10 to 15 percent and fifth-wheel or
gooseneck kingpin weight should be
15 to 25 percent of the loaded trailer
weight up to the maximums for
vehicle series and hitch type
shown here:

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 (126,1)GMC Sierra Owner Manual - 2011
9-126 Driving and Operating
Say, for example, you have a 318 kg
(700 lb) snow plow. The total weight
of all occupants and cargo inside
the cab should not exceed 135 kg
(300 lb). This means that you may
only be able to carry one passenger.
But, even this may be too much
if you have got other equipment
already adding to the weight of
the vehicle.
Here are some guidelines for safely
carrying a snow plow on the vehicle:
.Make sure the weight on the
front and rear axles does not
exceed the axle rating for each.
.For the front axle, if more cargo
or passengers must be carried,
appropriate counter ballast must
be installed rear of the rear axle.
Counter ballast must be properly
secured so it will not move
during driving.
.Follow the snow
plow manufacturer's
recommendations regarding
rear ballast. Rear ballast may
be required to ensure a proper
front and rear weight distribution
ratio, even though the actual
weight at the front axle may be
less than the front axle rating.
.The snow plow manufacturer
or installer can assist you in
determining the amount of rear
ballast required, to help make
sure the snowplow/vehicle
combination does not exceed
the GVW rating, the front and
rear axle ratings, and the front
and rear weight distribution ratio.
.The total vehicle must not
exceed the GVW rating.
Front axle reserve capacity is the
difference between the Gross Axle
Weight Rating (GAWR) and the front
axle weight of the vehicle with full fuel and passengers. Basically,
it is the amount of weight that can
be added to the front axle before
reaching the front GAWR.
The front axle reserve capacity
for the vehicle can be found
in the lower right corner of the
Certification/Tire label, as shown.
United States