2004 CHEVROLET OPTRA check engine light

Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly — and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
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{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 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.
Charging System Light
The charging system light
will come on briefly when
you turn on the ignition,
and the engine is not
running, as a check
to show you it is working.
Then it should go out when the engine is started.
If it stays on, or comes on while you are driving, you
may have a problem with the electrical charging system.
It could indicate that you have a loose generator drive
belt, or another electrical problem. Have it checked right
away. Driving while this light is on could drain your
battery.
If you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the radio
and air conditioner.
3-29

Anti-Lock Brake System Warning
Light
If your vehicle has an
anti-lock brake system, this
light will come on when the
ignition is turned to ON and
may stay on for several
seconds. That is normal.
If the light stays on, turn the ignition to LOCK. Or, if the
light comes on, 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. SeeBrake System Warning
Light on page 3-30.
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.
Speed Sensitive Power Steering
(SSPS) Warning Light
If your vehicle has Speed
Sensitive Power Steering
(SSPS), this warning
light will come on briefly
when you turn the ignition
to ON as a check to
show you it is working.
Then it should go out after a few seconds.
If the warning light does not come on, have it fixed so it
will be able to warn you if there is a problem.
If the warning light stays on, or comes on while you are
driving, the SSPS system may not be working. If this
happens, see your dealer for service.
3-31

Hold Mode Light
If your vehicle has this
feature, this light will come
on when the hold mode
is active.
If the HOLD mode light flashes, have your vehicle
checked. See “Hold Mode” underAutomatic Transaxle
Operation on page 2-23for additional information
on this feature.
Engine Coolant Temperature Gage
Your vehicle has an
engine coolant temperature
gage. With the ignition
turned to ON, this
gage shows the engine
coolant temperature.
If the gage pointer moves into the red area, your engine
is too hot. It 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.
SeeEngine Overheating on page 5-24.
3-32

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.
Notice:Modications made to the engine,
transaxle, exhaust, intake or fuel system of your
vehicle or replacement tires that do not match your
vehicle’s original tires 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.
When the ignition is on, this light should come on and
should go out after a few seconds as a check to
show you it is working. If the light does not come on,
have it repaired.
3-33

Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misfiring, hesitation
on acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to fix any
mechanical or electrical problems that may have
developed.Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the Check
Engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-35

Oil Pressure Light
If you have a low engine
oil pressure problem, this
light will stay on after
you start your engine, or
come on when you
are driving. This indicates
that your engine is not
receiving enough oil.
The engine could be low on oil, or could have some
other oil problem. Have it fixed immediately.
The oil light could also come on in three other situations:
•When the ignition is on but the engine is not
running, the light will come on as a test to show you
it is working. The light will go out when you turn
the ignition on. If it does not come on with the
ignition on, you may have a problem with the fuse
or bulb. Have it fixed right away.
•If you are idling at a stop sign, the light may blink
on and then off.
•If you make a hard stop, the light may come on for
a moment. This is normal.
{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.
3-36

{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.
Then, shut the engine off and close the window almost all
the way to preserve the heat. Start the engine again and
repeat this only when you feel really uncomfortable from
the cold. But do it as little as possible. Preserve the fuel
as long as you can. To help keep warm, you can get out
of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
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