check engine light CHEVROLET SILVERADO 2003 1.G User Guide

Supplemental Brake Assist System
If your vehicle has vacuum assist power brakes, it is also
equipped with a supplemental brake assist system
that supplies additional vacuum to the vacuum brake
booster if engine vacuum is reduced. Under certain
conditions, the supplemental brake assist system may
run brie¯y after starting your vehicle or when you
apply and release the brake pedal and it may continue
to run even after you have removed your foot from
the brake pedal. When the supplemental brake assist
system is operating, you may hear a motor running
or feel a slight vibration in the steering wheel or brake
pedal. This indicates that the supplemental brake
assist system is working to supply additional vacuum for
your vacuum assist power brakes. This is a normal
operation of your brake system and does not require that
the brake system be serviced.Each time you start your vehicle and accelerate to
10 mph, the supplemental brake assist system
will perform a self-diagnostic check of the system and
you may hear or feel the supplemental brake assist
motor run brie¯y. While you are driving your vehicle, the
supplemental brake assist system monitors itself to
ensure that it is operating properly. If there is a problem
with the supplemental brake assist system, the
SERVICE BRAKE BOOSTER message will be displayed
on the Driver Information Center. See
DIC Warnings
and Messages on page 3-65.
If your supplemental brake assist system runs every
time you apply and release the brake pedal or you notice
that the brake pedal has suddenly become much
harder to push and the vehicle takes longer to stop, you
should have your vehicle serviced as soon as possible.
4-9

·Put on extra clothing or wrap a blanket around you.
If you have no blankets or extra clothing, make
body insulators from newspapers, burlap bags, rags,
¯oor mats ± anything you can wrap around
yourself or tuck under your clothing to keep warm.
You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can not see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
4-51

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ¯ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ¯ash, telling other drivers
you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ¯ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It's
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
If you have an automatic transmission, you can tow in
DRIVE (D). You may want to shift the transmission
to lower gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See
Tow/Haul Mode
Light on page 3-53.If you have a 5-speed manual transmission and you are
towing a trailer, it's better not to use FIFTH (5) gear.
Just drive in FOURTH (4) gear (or, as you need
to, a lower gear).
If you have a 6-speed manual transmission and you are
towing a trailer, it's better not to use SIXTH (6) gear.
Drive in FIFTH (5) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) (or
the manual transmission out of gear and the parking
brake applied) for a few minutes before turning the
engine off. If you do get the overheat warning,
see
Engine Overheating on page 5-33.
4-87

CAUTION: (Continued)
·
Be sure to use the proper nuts, bolts and
other fasteners. ªEnglishº and ªmetricº
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the air¯ow around it. This may cause wind
noise and affect windshield washer performance. Check
with your dealer before adding equipment to the
outside of your vehicle.
Fuel
If your vehicle has a diesel engine, see ªDiesel Fuel
Requirements and Fuel Systemº in the Diesel Engine
Supplement.
For vehicles with gasoline engines, please read this.
Gasoline Octane
For all except the Silverado SS model, use regular
unleaded gasoline with a posted octane of 87 or higher.
If the octane is less than 87, you may get a heavy
knocking noise when you drive. If this occurs, use a
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine. A
little pinging noise when you accelerate or drive
uphill is considered normal. This does not indicate a
problem exists or that a higher-octane fuel is necessary.
If you are using 87 octane or higher-octane fuel and
hear heavy knocking, your engine needs service.
If you have the Silverado SS model, use premium
unleaded gasoline with a posted octane of 91 or higher
for best performance. You may also use middle
grade or regular unleaded gasoline rated at 87 octane
or higher, but your vehicle's acceleration may be slightly
reduced. If the octane is less than 87, you may get a
heavy knocking noise when you drive. If this occurs, use
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
5-4

Engine Oil
If your vehicle has a diesel engine, see ªEngine Oilº in
the Diesel Engine Supplement.
If the CHECK OIL LEVEL light appears on the
instrument cluster, it means you need to check your
engine oil level right away.
For more information, see
Driver Information Center
(DIC) on page 3-54.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.The engine oil dipstick has
a yellow ring handle and is
located in the engine
compartment on the
passenger's side of the
vehicle. See
Engine
Compartment Overview on
page 5-10
for more
information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
All Other Engines
5-16

As in the chart shown previously, SAE 5W-30 is the
only viscosity grade recommended for your vehicle. You
should look for and use only oils which have the API
Starburst symbol and which are also identi®ed as
SAE 5W-30. If you cannot ®nd such SAE 5W-30 oils,
you can use an SAE 10W-30 oil which has the API
Starburst symbol, if it's going to be 0ÉF (-18ÉC)
or above. Do not use other viscosity grade oils, such as
SAE 10W-40 or SAE 20W-50 under any conditions.
Notice:Use only engine oil with the American
Petroleum Institute Certi®ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
žoil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below-20ÉF (-29ÉC), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil
(GM Oil Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil and ®lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL light will come on.
Change your oil as soon as possible within the next
two times you stop for fuel. It is possible that, if you are
driving under the best conditions, the oil life system
may not indicate that an oil change is necessary for over
a year. However, your engine oil and ®lter must be
changed at least once a year and at this time the system
must be reset. Your dealer has GM-trained service
people who will perform this work using genuine GM
parts and reset the system. It is also important to check
your oil regularly and keep it at the proper level.
If the system is ever reset accidentally, you must change
your oil at 3,000 miles (5 000 km) since your last oil
change. Remember to reset the oil life system whenever
the oil is changed.
5-19

When to Check and What to Use
The clutch master cylinder
reservoir is located in the
rear of the engine
compartment on the
driver's side of the vehicle.
See
Engine Compartment
Overview on page 5-10
for more information
on location.
Refer to the Maintenance Schedule to determine how
often you should check the ¯uid level in your clutch
master cylinder reservoir and for the proper ¯uid. See
Part B: Owner Checks and Services on page 6-12andPart D: Recommended Fluids and Lubricants on
page 6-19.
How to Check and Add Fluid
The proper ¯uid should be added if the level does not
reach the bottom of the diaphragm when it's in place in
the reservoir. See the instructions on the reservoir cap.
Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add only
DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-33.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
5-30

On V6 engines the remote negative (-) terminal is
located on a tab attached to the engine accessory
drive bracket where it is marked ªGND.²
See
Engine Compartment Overview on page 5-10for more information on location.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
¯ashlight if you need more light.
Be sure the battery has enough water. You do
not need to add water to the ACDelco
žbattery
installed in your new vehicle. But if a battery
has ®ller caps, be sure the right amount of
¯uid is there. If it is low, add water to take care
of that ®rst. If you do not, explosive gas could
be present.
Battery ¯uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ¯ush the place
with water and get medical help immediately.
{CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
6. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or a remote positive terminal (+) if the
vehicle has one. Negative (-) will go to a heavy,
unpainted metal engine part or a remote
negative (-) terminal if the vehicle has one.
Don't connect positive (+) to negative (-) or you'll
get a short that would damage the battery and
maybe other parts too. And don't connect the
negative (-) cable to the negative (-) terminal on
the dead battery because this can cause sparks.
On vehicles equipped with dual batteries, make all
battery connections to the remote positive (+)
and remote negative (-) terminals.
5-50

Bulb Replacement (cont.)
Taillamps....................................................5-65
Buying New Tires...........................................5-74
C
California Fuel.................................................. 5-5
Canada ± Customer Assistance.......................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-6
Capacities and Speci®cations..........................5-118
Car Washes for QUADRASTEERŸ Equipped
Vehicles.....................................................4-18
Carbon Monoxide...................4-48, 4-68, 2-13, 2-51
Care of........................................................5-103
Safety Belts..............................................5-103
Your Cassette Tape Player..........................3-123
Your CD and DVD Player...........................3-124
Your CDs and DVDs..................................3-124
CARGO LAMP ON.........................................3-65
Cargo Lamp...................................................3-17
Cassette Tape Messages.................................3-94
Cassette Tape Player Service...........................6-12
CD Adapter Kits.............................................3-95
Center Console Storage Area...........................2-65
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp...............................................5-63
Center Instrument Panel Fuse Block................5-112
Center Passenger Position, Safety Belts.............1-24Chains, Tires..................................................5-78
CHANGE ENGINE OIL....................................3-66
Check Engine Light.........................................3-49
CHECK OIL LEVEL.........................................3-66
CHECK WASHER FLUID.................................3-66
Checking Brake Fluid......................................5-45
Checking Coolant............................................5-32
Checking Engine Oil........................................5-16
Checking Things Under the Hood....................... 5-8
Checking Your Restraint Systems......................1-81
Check...........................................................3-49
Engine Light...............................................3-49
Chemical Paint Spotting.................................5-106
Child Restraints..............................................1-38
Child Restraint Systems...............................1-38
Infants and Young Children...........................1-34
Lower Anchorages and Top Tethers for
Children (LATCH System)..........................1-47
Older Children.............................................1-31
Securing a Child Restraint Designed for the
LATCH System........................................1-49
Securing a Child Restraint in a Center Rear
Seat Position...........................................1-52
Securing a Child Restraint in a Rear Outside
Seat Position...........................................1-50
Securing a Child Restraint in the Center Front
Seat Position...........................................1-55
Securing a Child Restraint in the Right Front
Seat Position...................................1-55, 1-58
Top Strap Anchor Location............................1-44
3

Electrical System (cont.)
Power Windows and Other Power Options....5-109
Windshield Wiper Fuses.............................5-109
Electrochromic Mirror Operation................2-54, 2-57
Electronic Transfer Case..................................2-41
Emissions Inspection and Maintenance
Programs...................................................3-51
ENGINE COOLANT HOT.................................3-66
Engine Coolant Level Check.............................6-12
Engine Hour Meter Display...............................3-35
Engine Oil Additives........................................5-19
Engine Oil and Chassis Lubrication Scheduled
Maintenance................................................. 6-5
Engine Oil Level Check...................................6-12
ENGINE OVERHEATED..................................3-66
Engine..........................................................5-21
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-47
Check and Service Engine Soon Light............3-49
Compartment Overview................................5-10
Coolant Heater............................................2-24
Coolant Temperature Gage...........................3-47
Coolant......................................................5-30
Cooling System Inspection............................6-17
Exhaust.....................................................2-51
Fan Noise..................................................5-41
Oil .............................................................5-16
Overheating................................................5-33Engine (cont.)
Starting......................................................2-22
Entertainment System....................................3-125
Cleaning the Video Screen..........................3-125
DVD Distortion..........................................3-122
Entry Lighting.................................................3-18
Environmental Concerns..................................4-25
Exit Lighting...................................................3-18
Express Down Windows..................................2-16
Extended Cab and Crew Cab...........................1-50
Extended Cab................................................1-53
Extender, Safety Belt.......................................1-31
Exterior Lamps...............................................3-14
F
Filter.............................................................5-21
Engine Air Cleaner......................................5-21
Finding a PTY Station
(RDS and XMŸ).......................3-78, 3-88, 3-101
Finding a Station....................3-73, 3-76, 3-86, 3-99
Finish Care..................................................5-104
Finish Damage.............................................5-106
Five-Speed (VORTECŸ 4300 V6 and
4800 V8 Engines)........................................2-30
Five-Speed (VORTECŸ 6000 V8 Engine)...........2-29
Fixed Mast Antenna.......................................3-125
6