2011 GMC SIERRA service

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.

Black plate (120,1)GMC Sierra Owner Manual - 2011
9-120 Driving and Operating
The Trailer Brake Display Page can
be displayed by performing any of
the following actions:
.Scrolling through the DIC menu
pages using the odometer
trip stem or the DIC Vehicle
Information button (if equipped).
.Pressing a Trailer Gain
button—If the Trailer Brake
Display Page is not currently
displayed, pressing a Trailer
Gain button will first recall the
current Trailer Gain setting.
After the Trailer Brake Display
Page is displayed, each press
and release of the gain buttons
will then cause the Trailer Gain
setting to change.
.Activating the Manual Trailer
Brake Apply lever.
.Connecting a trailer equipped
with electric trailer brakes.All DIC warning and service
messages must first be
acknowledged by the driver
by pressing the odometer trip stem
or the DIC Vehicle Information
button (if equipped) before the
Trailer Brake Display Page can
be displayed and Trailer Gain
can be adjusted.
TRAILER GAIN: This setting is
displayed any time the Trailer Brake
Display Page is active. This setting
can be adjusted from 0.0 to 10.0
with either a trailer connected or
disconnected. To adjust the Trailer
Gain, press one of the Trailer Gain
adjustment buttons located on the
Trailer Brake Control Panel. Press
and hold a gain button to cause the
Trailer Gain to continuously adjust.
To turn the output to the trailer off,
adjust the Trailer Gain setting to
0.0 (zero).
0.0 (zero) gain is the factory default
setting. To properly adjust trailer
gain, see
“Trailer Gain Adjustment
Procedure” later in this section.
TRAILER OUTPUT: This is
displayed any time a trailer with
electric brakes is connected.
Output to the electric brakes is
based on the amount of vehicle
braking present and relative to
the Trailer Gain setting. Output
is displayed from 0 to 10 bars for
each gain setting.
On vehicles with Trailer Sway
Control (TSC) or Hill Start Assist
(HSA), output to the electric trailer
brakes may be displayed when the
systems are active. See Trailer
Sway Control (TSC) on page 9‑124
and Hill Start Assist (HSA) on
page 9‑70.

Black plate (121,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-121
The Trailer Output will indicate
“- - - - - -”on the Trailer Brake
Display Page whenever the
following occur:
.No trailer is connected
.A trailer without electric brakes
is connected (no DIC message
is displayed)
.A trailer with electric brakes
has become disconnected
(a CHECK TRAILER WIRING
message will also be displayed
on the DIC)
.There is a fault present in the
wiring to the electric trailer
brakes (a CHECK TRAILER
WIRING message will also be
displayed on the DIC)
.There is a fault in the ITBC
system (a SERVICE TRAILER
BRAKE SYSTEM message will
also be displayed in the DIC) Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is located on the Trailer
Brake Control Panel and is used
to apply the trailer
’s electric brakes
independent of the vehicle’s brakes.
This lever is used in the Trailer Gain
Adjustment Procedure to properly
adjust the power output to the trailer
brakes. Sliding the lever to the left
will apply only the trailer brakes.
The power output to the trailer is
indicated in the Trailer Brake
Display Page on the DIC. If the
vehicle’s service brakes are applied
while using the Manual Trailer Brake
Apply Lever, the trailer output power
will be the greater of the two.
The trailer's and the vehicle's brake
lamps will come on when either
vehicle braking or manual trailer
brakes are applied. Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and
must be adjusted any time vehicle
loading, trailer loading, or road
surface conditions change.
Setting the Trailer Gain properly
is needed for the best trailer
stopping performance. A trailer
that is over-gained may result in
locked trailer brakes. A trailer that
is under-gained may result in not
enough trailer braking. Both of
these conditions may result in
poorer stopping and stability of
the vehicle and trailer.

Black plate (124,1)GMC Sierra Owner Manual - 2011
9-124 Driving and Operating
SERVICE TRAILER BRAKE
SYSTEM: This message will be
displayed when there is a problem
with the ITBC system. If this
message persists over multiple
ignition cycles, there is a problem
with the ITBC system. Take the
vehicle to an authorized GM dealer
to have the ITBC system diagnosed
and repaired.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message is
displayed while driving the vehicle,
power is no longer available
to the trailer brakes. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.An authorized GM dealer may
be able to diagnose and repair
problems with the trailer. However,
any diagnosis and repair of the
trailer is not covered under the
vehicle warranty. Please contact
your trailer dealer for assistance
with trailer repairs and trailer
warranty information.
Trailer Sway
Control (TSC)
Trailer Sway Control (TSC)
2500 and 3500 series vehicles with
StabiliTrak have a Trailer Sway
Control (TSC) feature. If the vehicle
is towing a trailer and the system
detects that the trailer is swaying,
the vehicle's brakes are applied
without the driver pressing the brake
pedal. If the vehicle is equipped with
the Integrated Trailer Brake Control
(ITBC) system, StabiliTrak may also
apply the trailer brakes. The TCS/
StabiliTrak warning light will flash on
the instrument panel cluster to notify
the driver to reduce speed. If the
trailer continues to sway, StabiliTrak
will reduce engine torque to help
slow the vehicle.
Adding non‐dealer accessories can
affect the vehicle's performance.
See
Accessories and Modifications
on page 10‑3 for more information.

Black plate (1,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-7
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid (4-Speed
Transmission) . . . . . . . . . . . . . 10-13
Automatic Transmission Fluid (6-Speed
Transmission) . . . . . . . . . . . . . 10-16
Engine Air Cleaner/Filter . . . . 10-19
Cooling System . . . . . . . . . . . . 10-20
Engine Coolant . . . . . . . . . . . . . 10-22 Engine Overheating . . . . . . . . 10-25
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-28
Engine Fan . . . . . . . . . . . . . . . . . 10-28
Power Steering Fluid . . . . . . . 10-29
Washer Fluid . . . . . . . . . . . . . . . 10-29
Brakes . . . . . . . . . . . . . . . . . . . . . 10-30
Brake Fluid . . . . . . . . . . . . . . . . . 10-32
Battery . . . . . . . . . . . . . . . . . . . . . 10-34
Four-Wheel Drive . . . . . . . . . . . 10-34
Front Axle . . . . . . . . . . . . . . . . . . 10-36
Rear Axle . . . . . . . . . . . . . . . . . . 10-37
Noise Control System . . . . . . 10-38
Starter Switch Check . . . . . . . 10-39
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-40
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-40
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-40
Wiper Blade Replacement . . . . . . . . . . . . . . 10-41
Glass Replacement . . . . . . . . 10-41
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-42
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-44
Halogen Bulbs . . . . . . . . . . . . . . 10-44
Headlamps . . . . . . . . . . . . . . . . . 10-44
Pick-Up Box Identification and Fender Marker
Lamps . . . . . . . . . . . . . . . . . . . . 10-45
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-46
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-46
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-47
License Plate Lamp . . . . . . . . 10-48
Replacement Bulbs . . . . . . . . . 10-48
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-49
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-50
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-50
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-54

Black plate (2,1)GMC Sierra Owner Manual - 2011
10-2 Vehicle Care
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-57
Tire Sidewall Labeling . . . . . . 10-58
Tire Designations . . . . . . . . . . . 10-61
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-62
Tire Pressure . . . . . . . . . . . . . . . 10-66
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-67
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-68
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-69
Tire Inspection . . . . . . . . . . . . . . 10-73
Tire Rotation . . . . . . . . . . . . . . . 10-73
Dual Tire Rotation . . . . . . . . . . 10-75
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-76
Buying New Tires . . . . . . . . . . . 10-77
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-79 Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . 10-80
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-81
Wheel Replacement . . . . . . . . 10-82
Tire Chains . . . . . . . . . . . . . . . . . 10-83
If a Tire Goes Flat . . . . . . . . . . 10-84
Tire Changing . . . . . . . . . . . . . . 10-86
Full-Size Spare Tire . . . . . . . . 10-97
Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-98
Towing
Towing the Vehicle . . . . . . . . 10-103
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . 10-103
Appearance Care
Exterior Care . . . . . . . . . . . . . . 10-108
Interior Care . . . . . . . . . . . . . . . 10-112
Floor Mats . . . . . . . . . . . . . . . . . 10-116
General Information
For service and parts needs,
visit your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:

Black plate (3,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-3
California Proposition
65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to
cause cancer and birth defects or
other reproductive harm. Engine
exhaust, many parts and systems,
many fluids, and some component
wear by-products contain and/or
emit these chemicals.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer accessories
to the vehicle can affect vehicle
performance and safety, including
such things as airbags, braking,
stability, ride and handling,
emissions systems, aerodynamics,
durability, and electronic systems
like antilock brakes, traction control,
and stability control. Some of these
accessories could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from the installation or use
of non‐GM certified parts, including
control module modifications, is notcovered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. Your GM
dealer can accessorize the vehicle
using genuine GM Accessories.
When you go to your GM dealer
and ask for GM Accessories,
you will know that GM-trained and
supported service technicians will
perform the work using genuine
GM Accessories.
Also, see
Adding Equipment to
the Airbag-Equipped Vehicle on
page 3‑46.