2003 CHEVROLET CORVETTE check engine

Gasoline Speci®cations
It is recommended that gasoline meet speci®cations
which were developed by the American Automobile
Manufacturers Association and endorsed by the
Canadian Vehicle Manufacturers Association for better
vehicle performance and engine protection. Gasoline
meeting these speci®cations could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
ªAuto Makers' Choiceº
label on the pump.
California Fuel
If your vehicle is certi®ed to meet California Emission
Standards (see the underhood emission control label), it
is designed to operate on fuels that meet California
speci®cations. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
speci®cations, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see
Malfunction Indicator Lamp on page 3-38)
and your vehicle may fail a smog-check test. If this
occurs, return to your authorized GM dealer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs may not be covered
by your warranty.
Canada Only
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Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines may be
available in your area to contribute to clean air.
General Motors recommends that you use these
gasolines, particularly if they comply with the
speci®cations described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Don't use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage wouldn't be covered under your
warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to ®nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel wouldn't be
covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you'll be driving.
5-6

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing and tools away
from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a ®re. These include liquids like fuel,
oil, coolant, brake ¯uid, windshield washer and
other ¯uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

A. Coolant Surge Tank and Pressure Cap
B. Battery
C. Engine Oil Dipstick
D. Engine Oil Fill Cap
E. Engine Air Cleaner/Filter
F. Power Steering Fluid Reservoir
G. Brake Fluid Reservoir
H. Clutch Master Cylinder Reservoir
I. Windshield Washer Fluid Reservoir
Engine Oil
If the LOW OIL LEVEL message on the Driver
Information Center comes on, it means you need to
check your engine oil level right away. For more
information, see
Driver Information Center (DIC) on
page 3-44.
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 level 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
handle is a yellow ring
located near the coolant
surge tank. See
Engine
Compartment Overview on
page 5-12
for more
information on location.
Turn off the engine and give the oil a few 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 a
cloth, then push it back in all the way. Remove it
again, keeping the tip down.
5-13

Substitute Engine Oil:When adding oil to maintain
engine oil level, oil meeting GM Standard GM4718M
may not be available. You can add substitute oil
designated SAE 5W-30 with the starburst symbol at all
temperatures. If temperatures are above 0ÉF (-18ÉC),
you may substitute SAE 10W-30 with the starburst
symbol. Substitute oil not meeting GM Standard
GM4718M should not be used for an oil change.
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 that lets you know when to
change your 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 OIL SOON message 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.
5-16

Automatic Transmission Fluid
How to Check
It is not necessary to check the transmission ¯uid level.
A transmission ¯uid leak is the only reason for ¯uid
loss. If a leak occurs, take the vehicle to your dealer
service department and have it repaired as soon
as possible.
There is a special procedure for checking and changing
the transmission ¯uid. Because this procedure is
difficult, you should have this done at your dealer service
department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, see
Service
Publications Ordering Information on page 7-10.
Notice:We recommend you use only ¯uid labeled
DEXRONž-III, because ¯uid with that label is
made especially for your automatic transmission.
Damage caused by ¯uid other than DEXRON
ž-III is
not covered by your new vehicle warranty.Change both the ¯uid and ®lter every 50,000 miles
(80 000 km) if the vehicle is mainly driven under one of
these conditions:
·In heavy city traffic where the outside temperature
regularly reaches 90ÉF (32ÉC) or higher.
·In hilly or mountainous terrain.
·High performance operation.
If you do not use your vehicle under one of these
conditions, change the ¯uid and ®lter every
100,000 miles (166 000 km).
See
Scheduled Maintenance on page 6-4for the proper
service intervals for the transmission ¯uid and ®lter.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the ¯uid in your manual transmission
doesn't require changing.
5-20

How to Check
Because this operation can be difficult, you may choose
to have this done at your dealership service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading.
Notice:Too much or too little ¯uid can damage
your transmission. Too much can mean that some
of the ¯uid could come out and fall on hot engine
part or exhaust system parts, starting a ®re.
Too little ¯uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission ¯uid.
Check the ¯uid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your ®ngers on the
transmission case.Then, follow these steps:
1. Remove the ®ller plug.
2. Check that the lubricant level is up to the bottom of
the ®ller plug hole.
3. If the ¯uid level is good, install the plug and be sure
it is fully seated. If the ¯uid level is low, add more
¯uid as described in the next steps.
5-21

How to Add Fluid
Here's how to add ¯uid. Refer to the Maintenance
Schedule to determine what kind of ¯uid to use. See
Part D: Recommended Fluids and Lubricants on
page 6-14.
1. Remove the ®ller plug.
2. Add ¯uid at the ®ller plug hole. Add only enough
¯uid to bring the ¯uid level up to the bottom of the
®ller plug hole.
3. Install the ®ller plug. Be sure the plug is fully
seated.
4. Tighten the plug to 20 lb ft (27Y).
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is
self-adjusting. The master cylinder reservoir is ®lled with
hydraulic ¯uid.
It is not necessary to regularly check the ¯uid unless
you suspect there is a leak in the system. Adding ¯uid
won't correct a leak.
A ¯uid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
The clutch master cylinder reservoir is located at the
rear of the engine compartment on the driver's side. See
Engine Compartment Overview on page 5-12for
more information on location.
Refer to the Maintenance Schedule to determine how
often you should check the ¯uid level in your master
cylinder reservoir and for the proper ¯uid. See
Part B:
Owner Checks and Services on page 6-8andPart
D: Recommended Fluids and Lubricants on page 6-14.
5-22