2004 GMC ENVOY XL service

(A) Tire Size Code: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 Code” illustration
later in this section for more detail.
(B) Tire Performance Criteria Specication
(TPC Spec):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) Department of Transportation (DOT):
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.(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 5-68.
(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 seeInation - Tire
Pressure on page 5-64andLoading Your Vehicle
on page 4-49.
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(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) Tire Performance Criteria Specication
(TPC Spec):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) Dual Tire Maximum Load:Maximum load that
can be carried and the maximum pressure needed to
support that load when used in a dual conguration.
For information on recommended tire pressure see
Ination - Tire Pressure on page 5-64andLoading
Your Vehicle on page 4-49.
(D) Department of Transportation (DOT):
The Department of Transportation (DOT) code indicates
that the tire is in compliance with the U.S. Department
of Transportation Motor Vehicle Safety Standards.
LT-Metric Tire
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(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 illustration, it would mean that the tire’s sidewall
is 75% 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”.(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter “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 illustration, it would mean that the tire’s sidewall
is 75% as high as it is wide.Light Truck (LT-Metric) Tire
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(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”. The light truck tire size example
above shows dual or single tire congurations.
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 Ination 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. SeeInation - Tire Pressure on page 5-64.
Curb Weight:This means 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 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.
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Buying New Tires
To nd out what kind and size of tires you need, look
at the Certication/Tire label or the Tire and Loading
Information label. For examples of these labels and their
location on your vehicle, seeLoading Your Vehicle
on page 4-49.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specication (TPC Spec)
number on each tire’s sidewall. When you get new tires,
General Motors recommends that you get tires with
that same TPC Spec number. That way your vehicle will
continue to have tires that are designed to give proper
endurance, handling, speed rating, load range, traction,
ride and other things during normal service on your
vehicle. If your tires have an all-season tread design,
the TPC number will be followed by an “MS”
(for mud and snow).
If you ever replace your tires with those not having
a TPC Spec number, make sure they are the same
size, load range, speed rating and construction
type (bias, bias-belted or radial) as your original tires.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different
sizes or types (radial and bias-belted tires)
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires
on all wheels.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
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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, 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 Quality Grading
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.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specied government test course.
For example, a tire graded 150 would wear one and
a half (1.5) 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 signicantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on specied government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
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Description Usage
Swirl Remover PolishRemoves swirl marks, ne
scratches and other light
surface contamination.
Cleaner WaxRemoves light scratches
and protects nish.
Foaming Tire Shine
Low GlossCleans, shines and
protects in one easy step,
no wiping necessary.
Wash Wax ConcentrateMedium foaming
shampoo. Cleans and
lightly waxes.
Biodegradable and
phosphate free.
Spot LifterQuickly and easily
removes spots and stains
from carpets, vinyl and
cloth upholstery.
Odor EliminatorOdorless spray odor
eliminator used on fabrics,
vinyl, leather and carpet.
See your General Motors parts department for these
products. SeeRecommended Fluids and Lubricants
on page 6-13.Vehicle Identication
Vehicle Identication Number (VIN)
This is the legal identier for your vehicle. It appears on
a plate in the front corner of the instrument panel, on
the driver’s side. You can see it if you look through the
windshield from outside your vehicle. The VIN also
appears on the Vehicle Certication and Service Parts
labels and the certicates of title and registration.
Engine Identication
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specications
and replacement parts.
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Service Parts Identication Label
You’ll nd this label on the inside of the glove box.
It’s very helpful if you ever need to order parts.
On this label is:
your VIN,
the model designation,
paint information and
a list of all production options and special
equipment.
Be sure that this label is not removed from the vehicle.
Electrical System
Add-On Electrical Equipment
Notice:Don’t add anything electrical to your
vehicle unless you check with your dealer rst.
Some electrical equipment can damage your vehicle
and the damage wouldn’t be covered by your
warranty. Some add-on electrical equipment can
keep other components from working as they should.
Your vehicle has an air bag system. Before attempting
to add anything electrical to your vehicle, seeServicing
Your Air Bag-Equipped Vehicle on page 1-59.
Headlamps
The headlamp wiring is protected by four fuses.
An electrical overload will cause a lamp to go on and
off. If this happens, have your headlamp wiring checked
right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by a circuit
breaker and a fuse. If the motor overheats due to heavy
snow or ice, the wiper will stop until the motor cools.
If the overload is caused by some electrical problem,
be sure to get it xed.
Power Windows and Other Power
Options
Circuit breakers protect the power windows and other
power accessories. When the current load is too heavy,
the circuit breaker opens and closes, protecting the
circuit until the problem is xed or goes away.
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