
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.

Black plate (64,1)GMC Sierra Owner Manual - 2011
10-64 Vehicle Care
Maximum Inflation Pressure:
The maximum air pressure to
which a cold tire can be inflated.
The maximum air pressure is
molded onto the sidewall.
Maximum Load Rating
:
The load rating for a tire at the
maximum permissible inflation
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 68 kg (150 lbs). See Vehicle
Load Limits on page 9‑25. 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.
Passenger (P-Metric) Tire
:
A tire used on passenger cars
and some light duty trucks and
multipurpose vehicles.
Recommended Inflation
Pressure
:Vehicle
manufacturer's recommended
tire inflation pressure as
shown on the tire placard.
See Tire Pressure on
page 10‑66 andVehicle
Load Limits on page 9‑25.
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.

Black plate (69,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-69
When the malfunction indicator
is illuminated, the system may
not be able to detect or signal low
tire pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow
the TPMS to continue to function
properly.
SeeTire Pressure Monitor
Operation on page 10‑69 for
additional information.Federal Communications
Commission (FCC) and
Industry Canada
See Radio Frequency Statement on
page 13‑19 for information
regarding Part 15 of the Federal
Communications Commission
(FCC) rules and Industry Canada
Standards RSS-210/220/310.
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure
in the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. See Vehicle
Load Limits on page 9‑25.
A message to check the pressure
in a specific tire displays in the
Driver Information Center (DIC).
The low tire pressure warning
light and the DIC warning message
come on at each ignition cycle
until the tires are inflated to the
correct inflation pressure. If the
vehicle has DIC buttons, tire
pressure levels can be viewed.

Black plate (70,1)GMC Sierra Owner Manual - 2011
10-70 Vehicle Care
For additional information and
details about the DIC operation and
displays, seeDriver Information
Center (DIC) on page 5‑33 and
Tire Messages on page 5‑49.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven.
This could be an early indicator that
the air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information
label shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See Vehicle Load
Limits on page 9‑25, for an example
of the Tire and Loading Information
label and its location. Also see
Tire Pressure on page 10‑66. The TPMS can warn about a
low tire pressure condition but
it does not replace normal tire
maintenance. See
Tire Inspection
on page 10‑73, Tire Rotation on
page 10‑73 andTires on
page 10‑57.
Notice: Tire sealant materials are
not all the same. A non-approved
tire sealant could damage the
TPMS sensors. TPMS sensor
damage caused by using
an incorrect tire sealant is
not covered by the vehicle
warranty. Always use only
the GM-approved tire sealant
available through your dealer
or included in the vehicle.TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When
the system detects a malfunction,
the low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
.One of the road tires has been
replaced with the spare tire.
The spare tire does not have a
TPMS sensor. The malfunction
light and the DIC message
should go off after the road
tire is replaced and the sensor
matching process is performed
successfully. See "TPMS Sensor
Matching Process" later in this
section.

Black plate (71,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-71
.The TPMS sensor matching
process was not done or
not completed successfully
after rotating the tires. The
malfunction light and the DIC
message should go off after
successfully completing the
sensor matching process.
See "TPMS Sensor Matching
Process" later in this section.
.One or more TPMS sensors
are missing or damaged.
The malfunction light and
the DIC message should go
off when the TPMS sensors
are installed and the sensor
matching process is performed
successfully. See your dealer
for service.
.Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels
other than those recommended
could prevent the TPMS from
functioning properly. SeeBuying
New Tires on page 10‑77.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly, it cannot detect or signal a
low tire condition. See your dealer
for service if the TPMS malfunction
light and DIC message come on
and stay on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a
new tire/wheel position after rotating
the vehicle’ s tires or replacing
one or more of the TPMS sensors.
Also, the TPMS sensor matching
process should be performed after
replacing a spare tire with a road
tire containing the TPMS sensor.
The malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions,
using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool.

Black plate (75,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-75
{WARNING
Rust or dirt on a wheel, or on
the parts to which it is fastened,
can make wheel nuts become
loose after time. The wheel could
come off and cause an accident.
When changing a wheel, remove
any rust or dirt from places where
the wheel attaches to the vehicle.
In an emergency, use a cloth or a
paper towel to do this; but be sure
to use a scraper or wire brush
later, if needed, to get all the rust
or dirt off. SeeIf a Tire Goes Flat
on page 10‑84.
Lightly coat the center of the
wheel hub with wheel bearing
grease after a wheel change or
tire rotation to prevent corrosion
or rust build-up. Do not get
grease on the flat wheel
mounting surface or on
the wheel nuts or bolts.
If your vehicle has a Tire
Pressure Monitor System
(TPMS), reset the TPMS
sensors after rotating the tires.
See Tire Pressure Monitor
Operation on page 10‑69. Make sure the spare tire, if your
vehicle has one, is stored
securely. Push, pull, and then
try to rotate or turn the tire.
If it moves, tighten the cable.
See
“Storing a Flat or Spare
Tire and Tools” underTire
Changing on page 10‑86.
Dual Tire Rotation
When the vehicle is new,
or whenever a wheel, wheel
bolt or wheel nut is replaced,
check the wheel nut torque
after 160, 1 600 and 10 000 km
(100, 1,000 and 6,000 miles) of
driving. For proper torque and
wheel nut tightening information,
see “Removing the Spare Tire and
Tools” underTire Changing on
page 10‑86.

Black plate (77,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-77
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be
free of grease, gasoline or other
substances that can deteriorate
rubber.
Parking for an extended period
can cause flat spots on the tires
that may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires
or raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle.
The original equipment tires
installed on the vehicle, when
it was new, were designed to meet
General Motors Tire Performance
Criteria Specification (TPC Spec)
system rating. If you need
replacement tires, GM strongly
recommends that you get tires
with the same TPC Spec rating.
This way, the vehicle will continue
to have tires that are designed to
give the same performance and
vehicle safety, during normal use,
as the original tires.GM's exclusive TPC Spec system
considers over a dozen critical
specifications that impact the
overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire pressure
monitoring performance. GM's TPC
Spec number is molded onto the
tire's sidewall near the tire size.
If the tires have an all‐season
tread design, the TPC spec
number will be followed by an
MS for mud and snow. See
Tire
Sidewall Labeling on page 10‑58
for additional information.