2004 CHEVROLET CORVETTE service

Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows a deployed air bag symbol.
The system checks the air bag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the air bag
modules, the wiring and the diagnostic module. For
more information on the air bag system, seeAir
Bag System on page 1-40.
This light will come on
when you start your
vehicle, and it will flash for
a few seconds. Then the
light should go out. This
means the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to ON. If the
light does not come on then, have it fixed so it will
be ready to warn you if there is a problem.
3-35

{CAUTION:
If the air bag readiness light ever comes on
when you have turned off the air bag, it means
that something may be wrong with the air bag
system. The passenger’s air bag could inate
even though the switch is off. If this ever
happens, don’t let anyone whom the national
government has identied as a member of a
passenger air bag risk group sit in the
passenger’s position (for example, don’t
secure a rear-facing child restraint in your
vehicle) until you have your vehicle serviced.
See “Air Bag Off Switch” in the Index.
Voltmeter Gage
When the key is in ON
with the engine not
running, the voltmeter
shows the voltage output
of your battery. When
the engine is running, it
shows the voltage
output of the
charging system.
The reading will change as the rate of charge changes
(with engine speed, for example), but if the voltmeter
reads at 9 volts or below, your instrument panel cluster
and other systems may shut down. The Driver
Information Center (DIC) will read LOW VOLTAGE
when your vehicle is at 10 volts or below. Have
it checked right away. Driving with the voltmeter reading
at 10 volts or below could drain your battery and
disable your vehicle.
3-37

Brake System Warning Light
Your vehicle’s hydraulic brake system is divided into two
parts. If one part is not working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
This light should come on
when you turn the ignition
key to START. If it
does not come on then,
have it fixed so it will
be ready to warn you if
there is a problem.
If this warning light stays on after you start the engine,
the parking brake may still be set or there could be
a brake problem. Refer toParking Brake on page 2-31
to see if it is set. If the parking brake is not set, have
your brake system inspected right away.If the light comes on while you are driving and you have
a LOW BRAKE FLUID message showing on the DIC,
pull off the road and stop carefully. You may notice that
the pedal is harder to push. Or, the pedal may go
closer to the floor. It may take longer to stop. If the light
is still on, have the vehicle towed for service. See
Towing Your Vehicle on page 4-33.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you have pulled off the road and
stopped carefully, have the vehicle towed
for service.
3-38

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, the light will come
on when your engine is
started and may stay on for
several seconds. That is
normal.
If the light stays on, turn the ignition to OFF. Or, if the
light comes on when you are driving, stop as soon
as possible and turn the ignition off. Then start
the engine again to reset the system. If the light still
stays on, or comes on again while you are driving, your
vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but you do
not have anti-lock brakes. If the regular brake system
warning light is also on, you do not have anti-lock brakes
and there is a problem with your regular brakes. See
Brake System Warning Light on page 3-38. Also
see “Service ABS” underDIC Warnings and Messages
on page 3-58.
The anti-lock brake system warning light will come on
briefly when you turn the ignition key to ON. This is
normal. If the light does not come on then, have it fixed
so it will be ready to warn you if there is a problem.
Traction Control System (TCS)
Warning Light
This light should come on
briefly as you start the
engine. If the light does not
come on then, have it
fixed so it will be ready to
warn you if there is a
problem.
If it stays on, or comes on and the DIC shows a
SERVICE TRACTION SYSTEM message when you are
driving, there is a problem with your TCS system and
your vehicle needs service. When this light is on,
the system will not limit wheel spin. Adjust your driving
accordingly. If the driver turns off the Traction Control
System by pressing the button on the console, the TCS
system light will come on and the TRACTION SYSTEM
OFF message will show on the DIC.
3-39

Active Handling System Light
The Active Handling System light will come on briefly as
you start the engine. If the light does not come on
then, have it fixed so it will be ready to warn you if there
is a problem. The light will also come on while the
system warms up and the ACT HNDLING WARMING
UP message will be displayed in the Driver Information
Center (DIC).
If the light stays on or
comes on while you are
driving, a chime sounds
and a SERVICE ACTIVE
HNDLG message appears
on the DIC, there is a
problem with your Active
Handling System and
your vehicle needs service.The driver can acknowledge this message by pressing
the RESET button. When the SERVICE ACTIVE
HNDLG message is displayed, the Active Handling
System will not assist you in controlling the vehicle. You
should have the system serviced as soon as possible.
Adjust your driving accordingly.
When the system is working, you will see the ACTIVE
HANDLING message displayed in the DIC. You may also
feel or hear the system working. This is normal.
If the driver turns off the Active Handling System by
pressing the button on the console, the Active Handling
System light will come on, a chime will sound, and
the TRAC/ACT HNDLG OFF message will be displayed
in the DIC. The Traction Control System will also be
turned off. SeeDIC Warnings and Messages on
page 3-58for more information.
If the Active Handling System and the Traction Control
System are off, pressing the console button momentarily
will turn both systems on. The DIC will display the
TRAC/ACT HNDLG ON message, the instrument cluster
light will be off, and a chime will sound. SeeDIC
Warnings and Messages on page 3-58for more
information.
3-40

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the shaded area, your
engine is too hot.
This means that your engine coolant has overheated. If
you have been operating your vehicle under normal
driving conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
(The larger tic marks are in increments of 30° below
220°F (104°C) and in increments of 10° above
220°F (104°C).)
SeeEngine Overheating on page 5-26for more
information.
Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The CHECK ENGINE light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after a while, your emission controls
may not work as well, your fuel economy may not
be as good and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty. United States
Canada
3-41

Notice:Modications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
•Light Flashing— A misfire condition has been
detected. A misfire increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
•Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
•Reducing vehicle speed.
•Avoiding hard accelerations.
•Avoiding steep uphill grades.
If the light stops flashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to flash, when it is safe to do so,
stop the vehicle.Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
flashing, follow the previous steps, and see your dealer
for service as soon as possible.
3-42

The engine oil pressure can also be displayed using the
GAGES button on the Driver Information Center (DIC).
SeeDriver Information Center (DIC) on page 3-48.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
Security Light
This light comes on to
remind you to arm your
theft-deterrent system. If it
comes on and stays on
when your ignition is
on, there may be a
problem with your
theft-deterrent system.
SeeTheft-Deterrent System on page 2-16and
PASS-Key
®on page 2-18.
3-45