2008 CHEVROLET SILVERADO service

Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:

Removal of the noise shields or any underhood
insulation.
Engine:

Removal or rendering engine speed governor, if the
vehicle has one, inoperative so as to allow engine
speed to exceed manufacturer specications.
Fan and Drive:

Removal of fan clutch, if the vehicle has one, or
rendering clutch inoperative.
Removal of the fan shroud, if the vehicle has one.
Air Intake:

Removal of the air cleaner silencer.
Modication of the air cleaner.
Exhaust:

Removal of the muffler and/or resonator.
Removal of the exhaust pipes and exhaust pipe
clamps.
Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been preset at
the factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, the aim
of the headlamps can be affected and adjustment
can be necessary.
If oncoming vehicles ash their high beams at you, this
can mean the vertical aim of your headlamps needs
to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to be
adjusted. It is possible however, to re-aim the
headlamps as described.
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Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your vehicle Warranty
booklet for details.
{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much exing. You could have an air-out
and a serious accident. SeeLoading
Your Vehicle on page 4-36.
Underinated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your vehicle’s tires are cold. See
Inflation - Tire Pressure on page 5-76.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to
be cut, punctured, or broken by a
sudden impact — such as when you
hit a pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents.
If the tire’s tread is badly worn,
or if your vehicle’s tires have been
damaged, replace them.
20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use.
The low-prole, wide tread design is not
recommended for “off-road” driving or commercial
uses such as snow plowing. SeeOff-Road
Driving on page 4-12andAdding a Snow Plow or
Similar Equipment on page 4-43for additional
information.
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Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples
of a typical P-Metric and a LT-Metric tire sidewall.(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene 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.
(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications 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 Identication Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identication 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.
Passenger (P-Metric) Tire
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(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, seeUniform Tire Quality
Grading on page 5-89.
(G) Maximum Cold Ination Load Limit
:Maximum load that can be carried and the
maximum pressure needed to support that load.
For information on recommended tire pressure
seeInflation - Tire Pressure on page 5-76
andLoading Your Vehicle on page 4-36.
(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene 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.
Light Truck (LT-Metric) Tire
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Tire Size
The following examples show the different parts of
a tire size.
(A) Passenger (P-Metric) Tire
:The United States
version of a metric tire sizing system. The letter P
as the rst character in the tire size means a
passenger vehicle tire engineered to standards set
by the U.S. Tire and Rim Association.(A) Light Truck (LT-Metric) Tire
:The United
States version of a metric tire sizing system.
The letters LT as the rst two characters in the
tire size means a light truck 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 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.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
5-72

Federal Communications
Commission (FCC) and Industry and
Science Canada
The Tire Pressure Monitor System (TPMS) operates on
a radio frequency and complies with Part 15 of the
FCC Rules. Operation is subject to the following
two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
The TPMS operates on a radio frequency and complies
with RSS-210 of Industry and Science Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS), if your
vehicle has this feature, 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 vehicle’s tires
and transmits the tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure
condition is detected, the
TPMS will illuminate the
low tire pressure warning
symbol located on the
instrument panel cluster.
5-79

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 warning light
ashes for about one minute and then stays on for
the remainder of the ignition cycle. A DIC warning
message is also displayed. The low tire warning light
and DIC warning message come on at each ignition
cycle until the problem is corrected. Some of the
conditions that can cause the malfunction light and
DIC message 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 TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle’s tires. The DIC message
and TPMS malfunction light should go off once
the TPMS sensor matching process is performed
successfully. See “TPMS Sensor Matching Process”
later in this section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels.
Tires and wheels other than those recommended
for your vehicle could prevent the TPMS from
functioning properly. SeeBuying New Tires on
page 5-86.
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 it cannot detect or signal
a low tire condition. See your dealer/retailer for service
if the TPMS malfunction light and DIC message comes
on and stays on.
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TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes
will need to be matched to the new tire/wheel position.
The sensors are matched to the tire/wheel positions
in the following order: driver side front tire, passenger
side front tire, passenger side rear tire, and driver
side rear tire using a TPMS diagnostic tool. See your
dealer/retailer for service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do
not exceed the maximum ination pressure indicated on
the tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all
four tire/wheel positions. If it takes longer than
two minutes, to match the rst tire and wheel, or more
than ve minutes to match all four tire and wheel
positions the matching process stops and you need to
start over.The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
LOCK and UNLOCK buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode and
TIRE LEARNING ACTIVE message displays on the
DIC screen.
If your vehicle does not have RKE, press the Driver
Information Center (DIC) vehicle information
button until the PRESS
VTO RELEARN TIRE
POSITIONS message displays. The horn sounds
twice to signal the receiver is in relearn mode
and TIRE LEARNING ACTIVE message displays on
the DIC screen.
If your vehicle does not have RKE or DIC buttons,
press the trip odometer reset stem located on
the instrument panel cluster until the PRESS
VTO
RELEARN TIRE POSITIONS message displays.
The horn sounds twice to signal the receiver
is in relearn mode and TIRE LEARNING ACTIVE
message displays on the DIC screen.
4. Start with the driver side front tire.
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