2004 BUICK CENTURY service reset

Anti-Lock Brake System Warning
LightIf the vehicle has anti-lock brakes, this warning light will
come on for a few seconds when the ignition key is
turned to RUN. If the anti-lock brake system warning
light stays on longer than normal after the engine
has been started, turn the ignition off. Or, if the light
comes on and stays on while the vehicle is being driven,
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 driving,
the anti-lock brake system needs service. If the light is
on and the regular brake system warning light is not
on, the vehicle still has brakes, but it does not have
anti-lock brakes.
The anti-lock brake system warning light will come on
briey when the ignition key is turned to RUN. This
is normal. If the light does not come on then, have it
xed so it will be ready to warn you if there is a problem. United States
Canada
3-33

Tire Pressure Light
The vehicle may have a
tire pressure monitor that
indicates a large change
in the pressure in one tire.
The system stores the tire pressures of the vehicle’s
properly inated tires. The LOW TIRE light will come on
if the pressure in one tire becomes 12 psi (83 kPa)
lower than the other three tires. The LOW TIRE light will
not come on if the pressure in more than one tire is
low, if the system is not yet calibrated, or if the vehicle
is moving faster than 70 mph (110 km/h).
When the LOW TIRE light comes on, stop as soon as
possible and check all the tires for damage. If a tire
is at, seeIf a Tire Goes Flat on page 5-74. Also check
the tire pressure in all four tires as soon as possible.
SeeInation - Tire Pressure on page 5-64.
The light will stay on, while the ignition is on, until the
system is reset. SeeTire Pressure Monitor System
on page 5-65.
Malfunction Indicator Lamp
Service Engine Soon 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 SERVICE ENGINE SOON light
comes on and a chime will sound 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.
3-36

Change Engine Oil Light
The CHANGE OIL SOON
light should come on
briey as a bulb check
when the engine is started.
If the light does not
come on, have it serviced.
If the CHANGE OIL SOON light comes on and stays on
after the engine is started, have the oil changed.
For additional information, see “When to Change Engine
Oil (GM Oil Life System)” underEngine Oil on
page 5-13. To reset the CHANGE OIL SOON light, see
“How to Reset the System” underEngine Oil on
page 5-13.
Security Light
The SECURITY light will
come on when the key is
turned to START, and
will stay on until the
vehicle starts.
It will also ash if the ignition key is too dirty or wet for
the PASS-Key
®II system to read the resistor pellet.
SeePASS-Key®II on page 2-17.
If the resistor pellet is damaged or missing, the light will
come on.
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For best results, use a scrubbing action, non-abrasive
cleaning cassette with pads which scrub the tape
head as the hubs of the cleaner cassette turn. The
recommended cleaning cassette is available through
your dealership.
The cut tape detection feature of your cassette tape
player may identify the cleaning cassette tape as
a damaged tape, in error. If the cleaning cassette ejects,
insert the cassette at least three times to ensure
thorough cleaning.
You may also choose a non-scrubbing action, wet-type
cleaner which uses a cassette with a fabric belt to
clean the tape head. This type of cleaning cassette will
not eject on its own. A non-scrubbing action cleaner
may not clean as thoroughly as the scrubbing type
cleaner. The use of a non-scrubbing action, dry-type
cleaning cassette is not recommended.
After you clean the player, press and hold the eject
button for ve seconds to reset the CLEAN PLAYER
indicator. The radio will display --- to show the indicator
was reset.
Cassettes are subject to wear and the sound quality
may degrade over time. Always make sure the cassette
tape is in good condition before you have your tape
player serviced.Care of Your CDs
Handle CDs carefully. Store them in their original cases
or other protective cases and away from direct
sunlight and dust. If the surface of a CD is soiled,
dampen a clean, soft cloth in a mild, neutral detergent
solution and clean it, wiping from the center to the edge.
Be sure never to touch the side without writing when
handling CDs. Pick up CDs by grasping the outer edges
or the edge of the hole and the outer edge.
Care of Your CD Player
The use of CD lens cleaners for CDs is not advised,
due to the risk of contaminating the lens of the CD optics
with lubricants internal to the CD mechanism.
Fixed Mast Antenna
The xed mast antenna can withstand most car washes
without being damaged. If the mast should ever
become slightly bent, you can straighten it out by hand.
If the mast is badly bent, you should replace it.
Check occasionally to be sure the mast is still tightened
to the fender. If tightening is required, tighten by
hand, then with a wrench one quarter turn.
3-64

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 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 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.
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How to Reset the CHANGE OIL SOON
Light
The GM Oil Life System calculates when to change
your engine oil and lter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE OIL SOON light being turned on, reset
the system.
After changing the engine oil, reset the system by
performing the following steps:
1. With the engine off, turn the ignition key to RUN.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds.
If the CHANGE OIL SOON light ashes, the system
is resetting.
3. Turn the key to OFF, then start the vehicle. The oil
life will change to 100 percent.
If the CHANGE OIL SOON light comes back on
when you start your vehicle, the engine oil life
system has not reset. Repeat the procedure.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
5-17

The system normally takes 15 to 20 minutes of driving
time in each of three speed ranges to determine
tire pressures. The speed ranges are 15 to 40 mph
(25 to 65 km/h), 40 to 65 mph (65 to 105 km/h)
and above 65 mph (105 km/h). When the storage of the
tire ination information is complete, the LOW TIRE
light will come on the instrument panel after two
to eight minutes if one tire is inated 12 psi (83 kPa)
less than the other three tires. Detection thresholds
may be higher and detection times may be longer on
rough roads, curves and at high speeds. The system is
not capable of ination differences at speeds greater
than 70 mph (110 km/h).
The tire ination monitor system will not alert you if the
pressure in more than one tire is low, if the system
is not properly calibrated, or if the vehicle is moving
faster than 70 mph (110 km/h).
The LOW TIRE light will stay on while the ignition is on,
until the system is resetDo not reset the tire ination monitor system without
rst correcting the cause of the problem and checking
and adjusting the pressure in all four tires. If the
system is reset when the tire pressures are incorrect, it
will not function properly and may not alert you when
a tire is low.
Any time a tire’s pressure is adjusted, the tires are
rotated, or one or more tires is repaired or replaced, the
tire ination monitor system will need to be reset. The
system also needs to be reset when new tires are
purchased and if the vehicle’s battery has been
disconnected.
To reset the system:
1. Turn the ignition to RUN.
2. Remove the passenger’s side instrument panel
cover to get to the fuse block.
3. Press and hold the RESET button in the fuse block
for about ve seconds.
4. The LOW TIRE light will come on and ash
three times. Then it will go off. If the light does
not go off, see your dealer for service.
5-66

Scheduled Maintenance
When the CHANGE OIL SOON light comes on, it
means that service is required for your vehicle. Have
your vehicle serviced as soon as possible within the
next 600 miles (1 000 km). It is possible that, if you
are driving under the best conditions, the engine oil
life system may not indicate that vehicle service
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 GM
Goodwrench dealer has GM-trained service technicians
who will perform this work using genuine GM parts
and reset the system.
If the engine oil life system is ever reset accidentally,
you must service your vehicle within 3,000 miles
(5 000 km) since your last service. Remember to reset
the oil life system whenever the oil is changed. See
Engine Oil on page 5-13for information on the Engine
Oil Life System and resetting the system.When the CHANGE OIL SOON light appears,
certain services, checks and inspections are required.
Required services are described in the following for
“MaintenanceI” and “MaintenanceII.” Generally,
it is recommended that your rst service be
MaintenanceI, your second service be MaintenanceII
and that you alternate MaintenanceIand MaintenanceII
thereafter. However, in some cases, MaintenanceII
may be required more often.
MaintenanceI— Use MaintenanceIif the light comes
on within ten months since vehicle was purchased or
MaintenanceIIwas performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the light comes on ten months
or more since the last service or if the light has not
come on at all for one year.
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