2011 GMC SIERRA service

Black plate (59,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-59
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet
or exceed all federal safety
guidelines.
(C) DOT (Department
of Transportation)
:The
Department of Transportation
(DOT) code indicates that
the tire is in compliance
with the U.S. Department of
Transportation Motor Vehicle
Safety Standards.
(D) Tire Identification Number
(TIN)
:The letters and numbers
following DOT code are the Tire
Identification Number (TIN). The
TIN shows the manufacturer and
plant code, tire size, and date
the tire was manufactured. The TIN is molded onto both
sides of the tire, although only
one side may have the date of
manufacture.
(E) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.
(F) Uniform Tire Quality
Grading (UTQG)
:Tire
manufacturers are required
to grade tires based on three
performance factors: treadwear,
traction, and temperature
resistance. For more
information, see Uniform Tire
Quality Grading on page 10‑80.
(G) Maximum Cold Inflation
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed
to support that load. For
information on recommended
tire pressure see Tire Pressure
on page 10‑66 andVehicle
Load Limits on page 9‑25.
Light Truck (LT-Metric) Tire
(A) Tire Size:The tire size
code is a combination of letters
and numbers used to define
a particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustration later in this
section for more detail.

Black plate (61,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-61
Tire Designations
Tire Size
The following examples show
the different parts of a tire size.
Passenger (P‐Metric) Tire
(A) Passenger (P‐Metric) Tire:
The United States version of
a metric tire sizing system.
The letter P as the first
character in the tire size
means a passenger vehicle
tire engineered to standards
set by the U.S. Tire and Rim
Association.
(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 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
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Light Truck (LT‐Metric) Tire
(A) Light Truck (LT‐Metric)
Tire
:The United States version
of a metric tire sizing system.
The letters LT as the first two
characters in the tire size means
a light truck tire engineered to
standards set by the U.S. Tire
and Rim Association.

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 (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 (78,1)GMC Sierra Owner Manual - 2011
10-78 Vehicle Care
GM recommends replacing tires in
sets of four. This is because uniform
tread depth on all tires will help
keep the vehicle performing most
like it did when the tires were new.
Replacing less than a full set of
tires can affect the braking and
handling performance of the vehicle.
SeeTire Inspection on page 10‑73
and Tire Rotation on page 10‑73 for
information on proper tire rotation.
{WARNING
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
dealer or authorized tire service
center should mount or dismount
the tires.
{WARNING
Mixing tires could cause you
to lose control while driving.
If you mix tires of different sizes,
brands, or types (radial and
bias-belted tires), the vehicle
might not handle properly, and
you could have a crash. Using
tires of different sizes, brands,
or types could also cause
damage to the vehicle. Be sure
to use the same size, brand,
and type of tires on all wheels.
This vehicle may have a different
size spare than the road tires
(those originally installed on the
vehicle). When new, the vehicle
included a spare tire and wheel
assembly with a similar overall
diameter as the vehicle's road
tires and wheels, so it is all right
to drive on it. Because this spare
was developed for use on the
vehicle, it will not affect vehicle
handling.
{WARNING
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If you must replace the vehicle's
tires with those that do not have
a TPC Spec number, make sure
they are the same size, load range,
speed rating, and construction type
(radial and bias‐belted tires) as the
vehicle's original tires.

Black plate (80,1)GMC Sierra Owner Manual - 2011
10-80 Vehicle Care
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance.
This applies only to vehicles
sold in the United States.
The grades are molded on the
sidewalls of most passenger car
tires. The Uniform Tire QualityGrading (UTQG) system
does not apply to deep
tread, winter-type snow tires,
space-saver, or temporary use
spare tires, tires with nominal
rim diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
General Motors passenger
cars and light trucks may vary
with respect to these grades,
they must also conform to
federal safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based
on the wear rate of the tire
when tested under controlled
conditions on a specified
government test course.
For example, a tire graded
150 would wear one and a
half (1½) times as well on
the government course as
a tire graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart significantly from the
norm due to variations in
driving habits, service practices
and differences in road
characteristics and climate.

Black plate (84,1)GMC Sierra Owner Manual - 2011
10-84 Vehicle Care
If a Tire Goes Flat
It is unusual for a tire to blowout
while you are driving, especially if
you maintain your vehicle's tires
properly. If air goes out of a tire,
it is much more likely to leak out
slowly. But if you should ever have
a blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot
off the accelerator pedal and grip
the steering wheel firmly. Steer to
maintain lane position, and then
gently brake to a stop, well off the
road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and
may require the same correction
you would use in a skid. In any rear
blowout remove your foot from theaccelerator pedal. Get the vehicle
under control by steering the way
you want the vehicle to go. It may
be very bumpy and noisy, but you
can still steer. Gently brake to a
stop, well off the road, if possible.
{WARNING
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has
been driven on while severely
underinflated or flat may cause
a blowout and a serious crash.
Never attempt to re-inflate a tire
that has been driven on while
severely underinflated or flat.
Have your dealer or an authorized
tire service center repair or
replace the flat tire as soon
as possible.
{WARNING
Lifting a vehicle and getting
under it to do maintenance or
repairs is dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.
If a tire goes flat, the next part
shows how to use the jacking
equipment to change a flat tire
safely.

Black plate (93,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-93
{WARNING
If wheel studs are damaged, they
can break. If all the studs on a
wheel broke, the wheel could
come off and cause a crash.
If any stud is damaged because
of a loose-running wheel, it could
be that all of the studs are
damaged. To be sure, replace all
studs on the wheel. If the stud
holes in a wheel have become
larger, the wheel could collapse in
operation. Replace any wheel if
its stud holes have become larger
or distorted in any way. Inspect
hubs and hub‐piloted wheels
for damage. Because of loose
running wheels, piloting pad
damage may occur and require
replacement of the entire hub, for
proper centering of the wheels.
When replacing studs, hubs,
wheel nuts or wheels, be sure to
use GM original equipment parts.
{WARNING
Wheel nuts that are improperly or
incorrectly tightened can cause
the wheels to become loose or
come off. The wheel nuts should
be tightened with a torque wrench
to the proper torque specification
after replacing. Follow the torque
specification supplied by the
aftermarket manufacturer when
using accessory locking wheel
nuts. SeeCapacities and
Specifications on page 12‑2 for
original equipment wheel nut
torque specifications.
Notice: Improperly tightened
wheel nuts can lead to brake
pulsation and rotor damage.
To avoid expensive brake repairs,
evenly tighten the wheel nuts
in the proper sequence and to
the proper torque specification.
See Capacities and Specifications
on page 12‑2 for the wheel nut
torque specification.
13. Tighten the nuts firmly in a crisscross sequence as shown
by turning the wheel wrench
clockwise.
For vehicles with dual wheels, have
a technician check the wheel nut
tightness of all wheels with a torque
wrench after the first 100 miles
(160 km) and then 1,000 miles
(1600 km) after that. Repeat
this service whenever you have
a tire removed or serviced. See
Capacities and Specifications on
page 12‑2 for more information.