light CHEVROLET ASTRO 2004 Repair Manual

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 In¯ation 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
In¯ation - Tire Pressure on page 5-66.
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 Identi®cation
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
Loading
Your Vehicle on page 4-30.
GAWR FRT:Gross Axle Weight Rating for the front
axle, see
Loading Your Vehicle on page 4-30.
GAWR RR:Gross Axle Weight Rating for the rear axle,
see
Loading Your Vehicle on page 4-30.
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.
There are 6.9 kPa's to one psi.
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 In¯ation Pressure:The maximum air
pressure to which a cold tire may be in¯ated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible in¯ation pressure for that tire.
5-64

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 pounds
(68 kg). See
Loading Your Vehicle on page 4-30.
Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of a 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 In¯ation Pressure:Vehicle
manufacturer's recommended tire in¯ation pressure and
shown on the tire placard. See
In¯ation - Tire Pressure
on page 5-66andLoading Your Vehicle on page 4-30.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 ªwear bars,º that show across the tread of a tire
when only 2/32 inch of tread remains. See
When It
Is Time for New Tires on page 5-69.
5-65

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 speci®ed 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 signi®cantly 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 speci®ed 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.
5-71

Vehicle Care/Appearance Materials
See your GM dealer for more information on purchasing
the following products.
Vehicle Care/Appearance Materials
Description Usage
Polishing Cloth
Wax-TreatedInterior and exterior polishing
cloth.
Tar and Road Oil
RemoverRemoves tar, road oil and
asphalt.
Chrome Cleaner and
PolishUse on chrome or stainless
steel.
White Sidewall Tire
CleanerRemoves soil and black
marks from whitewalls.
Vinyl CleanerCleans vinyl tops, upholstery
and convertible tops.
Glass CleanerRemoves dirt, grime, smoke
and ®ngerprints.
Chrome and Wire
Wheel CleanerRemoves dirt and grime from
chrome wheels and wire
wheel covers.
Finish EnhancerRemoves dust, ®ngerprints,
and surface contaminants.
Spray on wipe off.
Vehicle Care/Appearance Materials
(cont'd)
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. See
Part D: Recommended Fluids and
Lubricants on page 6-30.
5-94

Headlamp Wiring
The headlamp wiring is protected by a circuit breaker in
the lamp switch. An electrical overload will cause the
lamps to ¯icker on and off, or in some cases to remain
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, etc., the wiper will stop until the motor cools.
Although the circuit is protected from electrical overload,
overload due to heavy snow, etc., may cause wiper
linkage damage. Always clear ice and heavy snow from
the windshield before using the windshield wipers. If
the overload is caused by some electrical problem and
not snow, etc., be sure to get it ®xed.
Power Windows and Other Power
Options
Circuit breakers in the fuse panel 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.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of ®res caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical
size and rating.
Spare fuses and a fuse puller are located in the
underhood fuse block. You can remove fuses with the
fuse puller. Remember to replace any of the spare fuses
you use, so you will have some if you ever need them
again.
If you ever have a problem on the road and don't have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle
that you can get along without ± like the radio or
cigarette lighter ± and use its fuse, if it is the correct
amperage. Replace it as soon as you can.
There are two fuse blocks in your vehicle: one is inside
the vehicle and one is in the engine compartment.
5-96

Fuse/Circuit
Breaker Usage
3 Courtesy Lamps, Glove Box Lamp,
Dome Reading Lamps, Vanity Mirror
Lamps, Courtesy Lamps
4 Daytime Running Lamps Relay,
Instrument Panel Cluster
5 Rear Defogger
6 Cruise Module, Truck Body Control
Module, Instrument Panel Cluster,
Cruise Control Switch,
Electrochromic Mirror
7 Power Outlets, Subwoofer Ampli®er
8 Crank Circuit Fuse, Park/Neutral
Switch, Starter Enabler Relay
9 License Plate Lamp, Tailamps,
Parking Lamps, Ashtray Lamp,
Panel Lights, Trailer Taillamps, Front
and Rear Sidemarker Lamps, Door
Switch Illumination, Headlamp
Switch Illumination, Rear Seat Audio
Illumination, Truck Body Control
Module
10 Air Bag System
11 Not UsedFuse/Circuit
Breaker Usage
12 Blower Motor, Rear Air Conditioning
Relay Coil, Front Cont. Temp. Door
Motor, HI Blower Relay, Defogger
Timer Coil
13 Cigarette Lighter, Door Lock
Switches, Dutch Door Release
Module
14 Cluster Illumination, Climate
Controls, Chime Module, Radio
Illumination, Rear Heat Switch
Illumination, Rear Wiper/Washer
Switch Illumination, Rear Liftgate
Switch Illumination, Remote
Cassette Illumination, Overhead
Console, Truck Body Control
Illumination
15 Truck Body Module, Headlamp
Relay
16 Front Turn Signals, Rear Turn
Signals, Trailer Turn Signals,
Back-Up Lamps, Brake
Transmission Shift Interlock Solenoid
17 Front Wipers, Front Washer Pump
5-98

Fuse/Circuit
BreakerUsage
A/C COMPAir Conditioning Enable Relay and
Compressor
RR HTR/AC Rear Heater and Air Conditioning
ATC Active Transfer Case-L Van
FRT HVAC Front Heater and Air Conditioning
ENG-IOxygen Sensors, Camshaft Position
Sensor, Mass Air Flow Sensor,
Evaporative Emission Canister Vent
Solenoid
IGN-E Air Conditioning Enable Relay Coil
ECM-IFuel Injectors 1±6, Crankshaft
Position Sensot, VCM, Coil Driver
Module (EST), Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
Blank Not Used
Blank Not UsedFuse/Circuit
BreakerUsage
DIODE-1 Air Conditioning
Blank Not Used
Blank Not Used
Blank Not Used
LIGHTINGCourtesy Fuse, Power Adjust
Mirrors Fuse, Truck Body Control
Battery Fuse
BATTPower Accessory Circuit Breaker,
Stop/Hazard Fuse, Auxiliary Power
Fuse, Cigarette Lighter Fuse, Radio
Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABSElectronic Brake
Control Module
Blank Not Used
RAP Radio Accessory, Power Windows
HTD MIR/RR
DEFOGRear Window Defogger,Climate
Control Head
5-101

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals speci®ed to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any ¯uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in Part D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel ®ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOLž
coolant mixture if necessary. SeeEngine Coolant
on page 5-24for further details.
Windshield Washer Fluid Level Check
Check the windshield washer ¯uid level in the
windshield washer tank and add the proper ¯uid if
necessary. See
Windshield Washer Fluid on page 5-35for further details.
At Least Once a Month
Tire In¯ation Check
Visually inspect your tires and make sure tires are
in¯ated to the correct pressures. Do not forget to check
your spare tire. See
Tires on page 5-52for further details.
At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its job,
have it repaired. Have any torn or frayed safety belts
replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
6-24

A
Accessory Power Outlets.................................3-16
Activating the Theft-Deterrent Feature................3-48
Adding Equipment to Your Air Bag-Equipped
Vehicle.......................................................1-70
Adding Washer Fluid.......................................5-38
Additional Program Information........................... 7-8
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment............................5-95
Add-On Equipment..........................................4-35
Adjusting the Speakers (Balance/Fade)......3-40, 3-43
Air Bag
Readiness Light..........................................3-26
Air Bag System..............................................1-63
Adding Equipment to Your Air
Bag-Equipped Vehicle...............................1-70
How Does an Air Bag Restrain?....................1-67
Servicing Your Air Bag-Equipped Vehicle.........1-69
What Makes an Air Bag In¯ate?....................1-67
What Will You See After an Air
Bag In¯ates?...........................................1-68
When Should an Air Bag In¯ate?...................1-67
Where Are the Air Bags?..............................1-65
Air Cleaner/Filter, Engine.................................5-21
Airbag Sensing and Diagnostic Module (SDM)...... 7-9
All-Wheel Drive...............................................5-47All-Wheel Drive (AWD) System.........................2-24
All-Wheel-Drive Service Light............................3-35
AM ...............................................................3-50
AM-FM Radio.................................................3-39
Antenna, Fixed Mast.......................................3-50
Anti-lock Brake System..................................... 4-7
Anti-Lock Brake, System Warning Light..............3-29
Appearance Care............................................5-86
Care of Safety Belts....................................5-89
Chemical Paint Spotting...............................5-93
Cleaning the Inside of Your Vehicle................5-87
Cleaning the Outside of Your Vehicle..............5-90
Finish Damage............................................5-93
Sheet Metal Damage...................................5-92
Underbody Maintenance...............................5-93
Vehicle Care/Appearance Materials................5-94
Weatherstrips..............................................5-89
Ashtrays........................................................3-17
Audio System(s).............................................3-38
AM-FM Radio.............................................3-39
Care of Your CD Player...............................3-50
Care of Your CDs........................................3-50
Fixed Mast Antenna.....................................3-50
Radio with CD............................................3-41
Rear Seat Audio (RSA)................................3-46
1

Audio System(s) (cont.)
Setting the Time for Radios with HR and
MN Buttons.............................................3-38
Setting the Time for Radios with the
Set Button..............................................3-38
Theft-Deterrent Feature................................3-47
Understanding Radio Reception.....................3-50
Automatic Headlamp System............................3-13
Automatic Transmission
Fluid..........................................................5-22
Operation...................................................2-21
Automatic Transmission Check..........................6-25
Automatic Transmission Shift Lock Control
System Check.............................................6-26
B
Backing Up....................................................4-42
Battery..........................................................5-42
Battery Replacement......................................... 2-5
Battery Run-Down Protection............................3-16
Before Leaving on a Long Trip.........................4-21
Bench Seat............................................1-11, 1-58
Body Lubrication Service..................................6-25
Brake
Parking......................................................2-24Brake (cont.)
System Inspection.......................................6-29
System Warning Light..................................3-28
Brake Adjustment............................................5-41
Brake Fluid....................................................5-39
Brake Pedal Travel.........................................5-41
Brake Wear...................................................5-41
Brakes..........................................................5-39
Braking........................................................... 4-6
Braking in Emergencies..................................... 4-9
Break-In, New Vehicle.....................................2-17
Bucket Seats, Rear.........................................1-12
Bulb Replacement...........................................5-49
Front Turn Signal Lamps..............................5-53
Halogen Bulbs............................................5-49
Headlamps.................................................5-50
Replacement Bulbs......................................5-55
Taillamps....................................................5-54
Buying New Tires...........................................5-70
C
California Fuel.................................................. 5-5
Canada ± Customer Assistance.......................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-7
2