2011 GMC SIERRA service

Black plate (71,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-71
When the vehicle is started
and begins to move, the system
performs several diagnostic checks
to insure there are no problems.
The system may be heard or
felt while it is working. This is
normal and does not mean there
is a problem with the vehicle.
The system should initialize
before the vehicle reaches 32 km/h
(20 mph). In some cases, it may
take approximately 3.2 km (2 mi) of
driving before the system initializes.
If cruise control is being used when
StabiliTrak activates, the cruise
control automatically disengages.
The cruise control can be
re-engaged when road conditions
allow. SeeCruise Control on
page 9‑73 for more information.
If the system fails to turn on or
activate, the StabiliTrak light
along with one of the following
messages will be displayed
on the Driver Information
Center (DIC): TRACTION CONTROL OFF, SERVICE
TRACTION CONTROL,
STABILITRAK OFF, SERVICE
STABILITRAK. If these DIC
messages appear, make sure the
StabiliTrak system has not been
turned off using the StabiliTrak
on/off button. Then turn the vehicle
off, wait 15 seconds, and turn it
back on again to reset the system.
If any of these messages still
appear on the DIC, the vehicle
should be taken in for service.
For more information on the DIC
messages, see
Ride Control
System Messages on page 5‑47.
The StabiliTrak light will flash on the
instrument panel cluster when the
system is both on and activated. The system may be heard or felt
while it is working; this is normal.
The traction control disable button
is located on the instrument panel
below the climate controls.
The Traction Control System (TCS)
part of StabiliTrak can be turned
off by pressing and releasing the
StabiliTrak button. To disable both
TCS and StabiliTrak, press and
hold
5untilFilluminates and the
appropriate DIC message displays.
TCS and StabiliTrak can be turned
on by pressing and releasing the
StabiliTrak button if they are not
automatically shut off for any other
reason.

Black plate (73,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-73
The traction control system may
activate on dry or rough roads
or under conditions such as
heavy acceleration while turning
or abrupt upshifts/downshifts of the
transmission. When this happens,
a reduction in acceleration may be
noticed, or a noise or vibration may
be heard. This is normal.
If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control will
automatically disengage. Cruise
control may be reengaged when
road conditions allow. SeeCruise
Control on page 9‑73.
StabiliTrak may also turn off
automatically if it determines that
a problem exists with the system.
If the problem does not clear itself
after restarting the vehicle, see your
dealer for service. 2500 and 3500 series vehicles
with StabiliTrak have a Trailer Sway
Control (TSC) feature. See
Trailer
Sway Control (TSC) on page 9‑124.
2500 and 3500 series vehicles
with StabiliTrak have a Hill Start
Assist (HSA) feature. See Hill Start
Assist (HSA) on page 9‑70.
Adding non‐dealer accessories can
affect the vehicle's performance.
See Accessories and Modifications
on page 10‑3.
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.
Cruise Control
{WARNING
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. So, do not use
the cruise control on winding
roads or in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
For vehicles with cruise control, a
speed of about 40 km/h (25 mph)
or more can be maintained
without keeping your foot on the
accelerator. Cruise control does
not work at speeds below about
40 km/h (25 mph).

Black plate (77,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-77
How the System Works
URPA comes on automatically
when the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by audible
beeps. The interval between the
beeps becomes shorter as the
vehicle gets closer to the obstacle.
When the distance is less than
30 cm (12 in) the beeps are
continuous.
To be detected, objects must be at
least 25.4 cm (10 in) off the ground
and below tailgate level. Objects
must also be within 2.5 m (8 ft) from
the rear bumper. This distance may
be less during warmer or humid
weather.
The system can be disabled by
pressing the rear park aid disable
button located next to the radio.
The indicator light comes on and
PARK ASSIST OFF displays on the
Driver Information Center (DIC) to
indicate that URPA is off; seeObject
Detection System Messages on
page 5‑46.
Notice: If you use URPA while
the tailgate is lowered, it may
not detect an object behind your
vehicle, and you might back into
the object and damage your
vehicle. Always verify the tailgate
is closed when using URPA or
turn off URPA when driving with
the tailgate lowered.
When the System Does Not
Seem to Work Properly
The following messages may be
displayed on the DIC:
SERVICE PARK ASSIST: If this
message occurs, take the vehicle to
your dealer to repair the system.
PARK ASSIST OFF: This message
occurs if the driver disables the
system.
PARK ASST BLOCKED SEE
OWNERS MANUAL: This
message can occur under the
following conditions:
.The ultrasonic sensors are not
clean. Keep the vehicle's rear
bumper free of mud, dirt, snow,
ice, and slush. For cleaning
instructions, see “Washing the
Vehicle” underExterior Care on
page 10‑108.

Black plate (81,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-81
Rear Vision Camera Error
Messages
Service Rear Vision Camera
System:This message can display
when the system is not receiving
information it requires from other
vehicle systems.
If any other problem occurs or if a
problem persists, see your dealer.
Rear Vision Camera Location
The rear vision camera is located in
the bezel for the tailgate handle. The camera uses a special lens.
The distance of the image that
appears on the screen differs from
the actual distance. The area
displayed by the camera is limited.
The camera does not display
objects which are close to either
corner of the bumper or under the
bumper. The area displayed on
the screen can vary according
to vehicle orientation or road
conditions.
The following illustration shows
the field of view that the camera
provides.
A. View displayed by the camera
B. Corner of the rear bumper

Black plate (84,1)GMC Sierra Owner Manual - 2011
9-84 Driving and Operating
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines”in the
Duramax Diesel Supplement.
For Vehicles with gasoline engines,
please read this.
Gasoline
Use of the recommended fuel
is an important part of the proper
maintenance of this vehicle. To help
keep the engine clean and maintain
optimum vehicle performance, we
recommend the use of gasoline
advertised as TOP TIER Detergent
Gasoline.
Look for the TOP TIER label on the
fuel pump to ensure gasoline meets
enhanced detergency standards
developed by auto companies. A list
of marketers providing TOP TIER
Detergent Gasoline can be found
at www.toptiergas.com.
The eighth digit of the Vehicle
Identification Number (VIN) shows
the code letter or number that
identifies the vehicle's engine.
The VIN is at the top left of the
instrument panel. See Vehicle
Identification Number (VIN) on
page 12‑1.
Vehicles that have a FlexFuel badge
and a yellow fuel cap can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). See
Fuel E85 (85% Ethanol) on
page 9‑87. For all other vehicles,
use only the unleaded gasoline
described under Recommended
Fuel on page 9‑84.
Recommended Fuel
For all vehicles except those with
the 6.2L V8 engine (VIN Code 2),
use regular unleaded gasoline
with a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving.
If this occurs, use a gasoline rated
at 87 octane or higher as soon
as possible. If heavy knocking is
heard when using gasoline rated
at 87 octane or higher, the engine
needs service.

Black plate (85,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-85
If the vehicle has the 6.2L V8 engine
(VIN Code 2), use premium
unleaded gasoline with a posted
octane rating of 91 or higher.
You can also use regular unleaded
gasoline rated at 87 octane or
higher, but the vehicle's acceleration
could be slightly reduced, and
a slight audible knocking noise,
commonly referred to as spark
knock, might be heard. If the octane
is less than 87, you might notice
a heavy knocking noise when you
drive. If this occurs, use a gasoline
rated at 87 octane or higher as soon
as possible. Otherwise, you could
damage the engine. If heavy
knocking is heard when using
gasoline rated at 87 octane or
higher, the engine needs service.Gasoline Specifications
(U.S. and Canada Only)
At a minimum, gasoline should
meet ASTM specification
D 4814 in the United States
or CAN/CGSB‐3.5 or 3.511 in
Canada. Some gasolines contain
an octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. SeeFuel Additives
on page 9‑86 for additional
information.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards,
it is designed to operate on fuels
that meet California specifications.
See the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog‐check test.
See Malfunction Indicator Lamp on
page 5‑25. If this occurs, return to
your authorized dealer for diagnosis.
If it is determined that the condition
is caused by the type of fuel used,
repairs might not be covered by the
vehicle warranty.

Black plate (87,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-87
Some gasolines that are
not reformulated for low
emissions can contain an
octane-enhancing additive
called methylcyclopentadienyl
manganese tricarbonyl (MMT);
ask the attendant where you buy
gasoline whether the fuel contains
MMT. We recommend against
the use of such gasolines. Fuels
containing MMT can reduce
spark plug life and affect emission
control system performance.
The malfunction indicator lamp
might turn on. If this occurs,
return to your dealer for service.
Fuel E85 (85% Ethanol)
Vehicles that have a FlexFuel badge
and a yellow fuel cap can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85).
For all other vehicles, use only the
unleaded gasoline described under
Recommended Fuel on page 9‑84.We encourage the use of E85 in
vehicles that are designed to use it.
The ethanol in E85 is a
“renewable”
fuel, meaning it is made from
renewable sources such as corn
and other crops.
Many service stations will not have
an 85% ethanol fuel (E85) pump
available. The U.S. Department
of Energy has an alternative fuels
website (www.afdc.energy.gov/afdc/
locator/stations/) that can help you
find E85 fuel. Those stations that
do have E85 should have a label
indicating ethanol content. Do not
use the fuel if the ethanol content is
greater than 85%.
At a minimum, E85 should meet
ASTM Specification D 5798.
By definition, this means that fuel
labeled E85 will have an ethanol
content between 70% and 85%.
Filling the fuel tank with fuel
mixtures that do not meet ASTM
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on. To ensure quick starts in the
wintertime, the E85 fuel must be
formulated properly for your climate
according to ASTM specification
D 5798. If you have trouble starting
on E85, it could be because the
E85 fuel is not properly formulated
for your climate. If this happens,
switching to gasoline or adding
gasoline to the fuel tank can
improve starting. For good starting
and heater efficiency below 0°C
(32°F), the fuel mix in the fuel tank
should contain no more than 70%
ethanol. It is best not to alternate
repeatedly between gasoline and
E85. If you do switch fuels, it is
recommended that you add as
much fuel as possible
—do not
add less than 11 L (3 gal) when
refueling. You should drive the
vehicle immediately after refueling
for at least 11 km (7 mi) to allow
the vehicle to adapt to the change
in ethanol concentration.

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.