weight HUMMER H3 2009 Owner's Manual

Trailer Brake Control Wiring
Harness
The trailer brake control wiring
harness is located under the
instrument panel to the right of the
steering column. The wires are
taped to the harness that goes to
the courtesy light under the
instrument panel. The harness has
the following wires:
Red Wire: AUX B+
Black Wire: Ground
Light Blue Wire: Brake Signal
Dark Blue Wire: Trailer Brakes
Trailer Recommendations
Subtract the hitch loads from the
Cargo Weight Rating (CWR). CWR
is the maximum weight of the
load the vehicle can carry. It does
not include the weight of the people
inside, but you can gure about
150 lbs. (68 kg) for each passenger.
The total cargo load must not be
more than the vehicles CWR.
Weigh the vehicle with the trailer
attached, so the GVWR or GAWR
are not exceeded. If using a
weight-distributing hitch, weigh the
vehicle without the spring bars
in place.
The best performance is obtained
by correctly spreading out the weight
of the load and choosing the
correct hitch and trailer brakes.
For more information seeTowing a
Trailer on page 4-42.
Driving Your Vehicle 4-53

(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) Service Description
:The service description indicates
the load range and speed
rating of a tire. The load index
can range from 1 to 279. Speed
ratings range from A to Z.
Tire Terminology and
Denitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in pounds per square
inch (psi) or kilopascal (kPa).
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.
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 pounds per
square inch (psi) or kilopascals
(kPa) before a tire has built
up heat from driving. See
Inflation - Tire Pressure on
page 5-51.
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.
5-48 Service and Appearance Care

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 Identication
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and date
of production.
GVWR
:Gross Vehicle Weight
Rating. SeeLoading the Vehicle
on page 4-35.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
SeeLoading the Vehicle on
page 4-35.
GAWR RR
:Gross Axle
Weight Rating for the rear axle.
SeeLoading the Vehicle on
page 4-35.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.
Maximum Ination Pressure
:The maximum air pressure
to which a cold tire can be
inated. The maximum air
pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire at the
maximum permissible ination
pressure for that tire.Maximum Loaded Vehicle
Weight
:The sum of curb
weight, accessory weight,
vehicle capacity weight, and
production options weight.
Normal Occupant Weight
:The number of occupants
a vehicle is designed to seat
multiplied by 150 lbs (68 kg).
SeeLoading the Vehicle
on page 4-35.
Occupant Distribution
:Designated seating positions.
Outward Facing Sidewall
:The side of an asymmetrical tire
that has a particular side that
faces outward when mounted on
a vehicle. The side of the tire
that contains a whitewall,
bears white lettering, or bears
manufacturer, brand, and/or
model name molding that
is higher or deeper than the
same moldings on the
other sidewall of the tire.
Service and Appearance Care 5-49

Passenger (P-Metric) Tire:A tire used on passenger cars
and some light duty trucks
and multipurpose vehicles.
Recommended Ination
Pressure
:Vehicle
manufacturer’s recommended
tire ination pressure as
shown on the tire placard.
SeeInflation - Tire Pressure on
page 5-51andLoading the
Vehicle on page 4-35.
Radial Ply Tire
:A pneumatic
tire in which the ply cords that
extend to the beads are laid
at 90 degrees to the centerline
of the tread.
Rim
:A metal support for a tire
and upon which the tire beads
are seated.
Sidewall
:The portion of a tire
between the tread and the bead.
Speed Rating
:An alphanumeric
code assigned to a tire indicating
the maximum speed at which a
tire can operate.Traction
:The friction between
the tire and the road surface.
The amount of grip provided.
Tread
:The portion of a tire that
comes into contact with the road.
Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1/16 inch
(1.6 mm) of tread remains.
SeeWhen It Is Time for New
Tires on page 5-58.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that provides
consumers with ratings for a
tire’s traction, temperature,
and treadwear. Ratings are
determined by tire manufacturers
using government testing
procedures. The ratings are
molded into the sidewall of the
tire. SeeUniform Tire Quality
Grading on page 5-62.Vehicle Capacity Weight
:The number of designated
seating positions multiplied
by 150 lbs (68 kg) plus the rated
cargo load. SeeLoading the
Vehicle on page 4-35.
Vehicle Maximum Load on
the Tire
:Load on an individual
tire due to curb weight,
accessory weight, occupant
weight, and cargo weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the vehicle’s
capacity weight and the
original equipment tire size
and recommended ination
pressure. See “Tire and
Loading Information Label”
underLoading the Vehicle
on page 4-35.
5-50 Service and Appearance Care

Ination - Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
Notice:Do not let anyone tell
you that under-ination or
over-ination is all right. It is
not. If your tires do not have
enough air (under-ination),
you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air
(over-ination), you can get
the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road
hazardsA vehicle specic Tire and
Loading Information label is
attached to your vehicle.
This label shows your vehicle’s
original equipment tires and
the correct ination pressures for
your tires when they are cold.
The recommended cold tire
ination pressure, shown on the
label, is the minimum amount
of air pressure needed to
support your vehicle’s maximum
load carrying capacity.
For additional information
regarding how much weight your
vehicle can carry, and an
example of the Tire and Loading
Information label, seeLoading
the Vehicle on page 4-35.
How you load your vehicle
affects vehicle handling and ride
comfort. Never load your vehicle
with more weight than it was
designed to carry.When to Check
Check your tires once a month
or more. Also check the tire
pressure of the spare tire. If your
vehicle has a compact spare
tire, it should be at 60 psi
(420 kPa). SeeSpare Tire on
page 5-82for additional
information.
How to Check
Use a good quality pocket-type
gage to check tire pressure.
You cannot tell if your tires are
properly inated simply by
looking at them. Radial tires may
look properly inated even
when they are underinated.
Check the tire’s ination
pressure when the tires are
cold. Cold means your vehicle
has been sitting for at least
three hours or driven no more
than 1 mile (1.6 km).
Service and Appearance Care 5-51