check engine light Oldsmobile Alero 2004 Owner's Manuals

•When an objectionable odor outside the vehicle is
encountered, use the recirculation mode, with the
temperature knob at a comfortable setting to prevent
the odor from entering the vehicle through the
ventilation system. This can be helpful when driving
through a long tunnel with poor ventilation.
However, extended usage of this mode in cold or
cool weather can cause window fogging.
Warning Lights, Gages and
Indicators
This part describes the warning lights and gages that may
be on your vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.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 are 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 is 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 are a big help.
3-23

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 doesn’t 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 when you
turn on the ignition, but the
engine is not running, as
a check to show you it
is working.
When the engine is running, the light should go out.
If it stays on, or comes on while you are driving and you
hear a chime, 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.
3-27

Low Coolant Warning Light
This light comes on
briefly when you turn your
ignition on.
If this light comes on and stays on and you hear a
chime, the coolant level in your vehicle is low.
SeeEngine Coolant on page 5-23. If the light is on
along with an overheat warning, you may have a serious
overheating problem. SeeEngine Coolant Temperature
Gage on page 3-31listed previously.
Notice:If you operate the engine without coolant
or fail to maintain the cooling system properly,
you could damage the engine. The repairs would not
be covered by your warranty. Always follow the
maintenance schedule in this manual for
maintaining your cooling system. SeeCooling
System on page 5-29for more information.
SeeEngine Overheating on page 5-26for information
on what to do. Your vehicle should be serviced as soon
as possible.
Malfunction Indicator Lamp
Service Engine Soon Light in the
United States or Check Engine Light in
Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.
United StatesCanada
3-32

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 SERVICE ENGINE SOON or 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 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 you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
3-33

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.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling Your Tank on page 5-6. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
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 5-4. 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.
3-34

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 in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON or 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.
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 and you will hear
a chime 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.
3-35

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,
but the light will go out when the engine is running. If
it doesn’t come on with the ignition on, you may have a
problem with the bulb. Have it fixed right away.
{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.
Change Engine Oil Light
The CHANGE OIL light
should come on briefly as
a bulb check when you
start the engine. If the light
doesn’t come on, have it
serviced.
If the CHANGE OIL light comes on and stays on after
you start the engine, have the oil changed.
To reset the CHANGE OIL light, seeEngine Oil on
page 5-15.
3-36

Anti-lock Brake System (ABS)
Your vehicle may have anti-lock brakes. ABS is an
advanced electronic braking system that will help
prevent a braking skid.
If your vehicle has anti-lock brakes, this warning light on
the instrument panel will come on briefly when you
start your vehicle.
When you start your engine, or when you begin to drive
away, your anti-lock brake system will check itself.
You may hear a momentary motor or clicking noise while
this test is going on, and you may even notice that
your brake pedal moves or pulses a little. This is normal.Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels. United States
Canada
4-7

Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), 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
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M 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 filter. 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 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 filter 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.
5-18

Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12for
more information on location.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at every oil change and
replace at the first oil change after
25,000 miles (40 000 km).
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake filter to release loose dust
and dirt. If the filter remains “caked” with dirt, a new
filter is required.
To inspect or replace the engine air cleaner/filter, do the
following:
1. Remove the screws that hold the cover on.
2. Lift off the cover.
3. Check or replace the engine air cleaner/filter.
4. Put the cover back on tightly.
Refer to the Maintenance Schedule to determine when
to replace the air filter.
SeeScheduled Maintenance on page 6-4. 2.2L L4 ECOTEC™ Engine shown, 3400 V6 Engine
similar
5-20