Black plate (117,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-117
If the vehicle is equipped with an
Integrated Trailer Brake Control
(ITBC) System, the blunt cuts
exist, but are not connected further
in the harness. If an aftermarket
trailer brake controller is installed,
the ITBC must be disconnected.
Do not power both ITBC and
aftermarket controllers to control
the trailer brakes at the same time.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
panel cluster comes on when the
Tow/Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. SeeTow/Haul
Mode on page 9‑51 for more
information.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing on page 9‑95.
Tow/Haul is most useful under
the following driving conditions:
.When pulling a heavy trailer or
a large or heavy load through
rolling terrain.
.When pulling a heavy trailer
or a large or heavy load in
stop-and-go traffic.
.When pulling a heavy trailer
or a large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no
trailer at all will not cause damage.
However, there is no benefit to
the selection of Tow/Haul when
the vehicle is unloaded. Such a
selection when unloaded may
result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large
or heavy load.
Black plate (125,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-125
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice:Do not add anything
electrical to the vehicle unless
you check with your dealer first.
Some electrical equipment can
damage the vehicle and the
damage would not be covered
by the vehicle's warranty. Some
add-on electrical equipment can
keep other components from
working as they should.
Add-on equipment can drain the
vehicle battery, even if the vehicle
is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle on page 3‑46 andAdding
Equipment to the Airbag-Equipped
Vehicle on page 3‑46.
Adding a Snow Plow or
Similar Equipment
Before installing a snow plow on the
vehicle, here are some things you
need to know:
Notice: If your vehicle does
not have the snow plow prep
package, adding a plow can
damage your vehicle, and the
repairs would not be covered by
warranty. Unless your vehicle was
built to carry a snow plow, do not
add one to your vehicle. If your
vehicle has the snow plow prep
package, called RPO VYU, then
the payload your vehicle can
carry will be reduced when a
snow plow is installed. Your
vehicle can be damaged if either
the front or rear axle ratings or
the Gross Vehicle Weight (GVW)
are exceeded. Some vehicles are built with a
special snow plow prep package,
called RPO VYU. If your vehicle
has this option, you can add a
plow to it, provided certain weights,
such as the weights on the vehicle's
axles and the Gross Vehicle
Weight (GVW), are not exceeded.
The plow the vehicle can carry
depends on many things, such as:
.The options the vehicle came
with, and the weight of those
options.
.The weight and number of
passengers you intend to carry.
.The weight of items added to
the vehicle, like a tool box or
truck cap.
.The total weight of any
additional cargo you intend
to carry.
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
Black plate (127,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-127
Canada
In order to calculate the amount of
weight any front accessory, such as
a snow plow, is adding to the front
axle, use the following formula:(W x (A + W.B.)) /W.B.= Weight
the accessory is adding to the
front axle.
Where: W = Weight of added accessory
A = Distance that the accessory
is in front of the front axle
W.B. = Vehicle Wheelbase For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lbs) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheel base is
305 cm (10 ft), then:
W = 318 kg (700 lb)
A = 122 cm (4 ft)
W.B. = 305 cm (10 ft)
(W x (A + W.B.))/W.B. =
(700 x (4 + 10))/10 = 445 kg (980 lbs)
So, if the front axle reserve capacity
is more than 445 kg (980 lbs), you
could add the snow plow without
exceeding the front GAWR.
You can add heavier equipment
on the front of the vehicle if you
compensate for it by carrying fewer
passengers, less cargo, or by
positioning cargo toward the rear.
Black plate (128,1)GMC Sierra Owner Manual - 2011
9-128 Driving and Operating
This has the effect of reducing the
load on the front. However, the front
GAWR, rear GAWR, and the Gross
Vehicle Weight Rating (GVWR) must
never be exceeded.
{WARNING
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front gross axle weight rating
(GAWR) but not have enough
weight on the rear axle to have
proper braking performance.
If your brakes can not work
properly, you could have a crash.
To help your brakes work properly
when a snow plow is installed,(Continued)
WARNING (Continued)
always follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio, even
though the actual front weight
may be less than the front
GAWR, and the total vehicle
weight is less than the gross
vehicle weight rating (GVWR).
Maintaining a proper front and
rear weight distribution ratio is
necessary to provide proper
braking performance. Total vehicle reserve capacity is the
difference between the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount of
weight that can be added to the
vehicle before reaching the GVWR.
Keep in mind that reserve capacity
numbers are intended as a guide
when selecting the amount of
equipment or cargo the truck can
carry. If unsure of the vehicle's front,
rear, or total weight, go to a weigh
station and weigh the vehicle.
Your dealer can also help with this.
The total vehicle reserve capacity
for the vehicle can be found
in the lower right corner of the
Certification/Tire label as shown
previously.
See your dealer for additional
advice and information about
using a snow plow on the vehicle.
Also, see
Vehicle Load Limits on
page 9‑25.
Black plate (38,1)GMC Sierra Owner Manual - 2011
10-38 Vehicle Care
.For all 6.0 L and 6.2 L 1500
Series applications, the proper
level is from 15 mm to 40 mm
(0.6 in to 1.6 in) below the
bottom of the fill plug hole,
located on the rear axle.
Add only enough fluid to
reach the proper level.
.For all 6.0 L 2500HD Series
applications, the proper level is
from 0 mm to 13 mm (0 to 0.5 in)
below the bottom of the fill plug
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
.For all 6.6 L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer toRecommended Fluids
and Lubricants on page 11‑8 to
determine what kind of lubricant
to use.
Noise Control System
The following information relates
to compliance with federal noise
emission standards for vehicles
with a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lbs). The Scheduled
Maintenance on page 11‑2 provides
information on maintaining the
noise control system to minimize
degradation of the noise emission
control system during the life of your
vehicle. The noise control system
warranty is given in your warranty
booklet. These standards apply only to
vehicles sold in the United States.
Federal law prohibits the following
acts or the causing thereof:
1. The removal or rendering
inoperative by any person,
other than for purposes
of maintenance, repair or
replacement, of any device or
element of design incorporated
into any new vehicle for the
purpose of noise control, prior to
its sale or delivery to the ultimate
purchaser or while it is in use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Black plate (62,1)GMC Sierra Owner Manual - 2011
10-62 Vehicle Care
(B) Tire Width:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the light truck
(LT‐Metric) tire illustration,
it would mean that the tire's
sidewall is 75 percent as high
as it is wide.
(D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or
bias ply construction; and the
letter B means belted‐bias ply
construction. (E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Load Range
:Load Range.
(G) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating
is the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount
of air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal). Accessory Weight
:This
means the combined weight
of optional accessories.
Some examples of optional
accessories are, automatic
transmission, power steering,
power brakes, power windows,
power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or
other reinforcing materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Black plate (63,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-63
Bias Ply Tire:A pneumatic
tire in which the plies are laid
at alternate angles less than
90 degrees to the centerline
of the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire Pressure
on page 10‑66.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including
the maximum capacity of fuel,
oil, and coolant, but without
passengers and cargo. DOT Markings
:A code
molded into the sidewall of
a tire signifying that the tire
is in compliance with the U.S.
Department of Transportation
(DOT) motor vehicle safety
standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
on page 9‑25.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
See Vehicle Load Limits on
page 9‑25. GAWR RR
:Gross Axle
Weight Rating for the rear axle.
See Vehicle Load Limits on
page 9‑25.
Intended Outboard Sidewall
:
The side of an asymmetrical tire,
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric
unit for air pressure.
Light Truck (LT‐Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.
Load Index
:An assigned
number ranging from 1 to 279
that corresponds to the load
carrying capacity of a tire.