2002 BUICK CENTURY Owner's Manual

2-73 Low Tire Light
The low tire inflation
monitor system can
alert you to a large
change in the pressure
in one tire.
After the system has ªlearnedº tire pressures with
properly inflated 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 inflation
monitor system won't alert you 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, you should stop
as soon as you can and check all your tires for damage.
(If a tire is flat, see ªIf a Tire Goes Flatº in the Index.)
Also check the tire pressure in all four tires as soon as
you can. See ªInflation
- Tire Pressureº in the Index.
The light will stay on (while the ignition is on) until you
reset (calibrate) the system. See ªLow Tire Inflation
Monitor Systemº in the Index.
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.

2-74
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:
Modifications 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 the SERVICE ENGINE SOON
light to come on. Modifications 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 doesn't 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. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center 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.

2-75
If the light stops flashing and remains on steady,
see ªIf the Light Is On Steadyº 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 ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
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. See ªFilling Your Tankº in the Index.
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.Are you low on fuel?
As your engine starts to run out of fuel, your engine
may not run as efficiently as designed since small
amounts of air are sucked into the fuel line causing a
misfire. The system can detect this. Adding fuel should
correct this condition. Make sure to install the fuel cap
properly. See ªFilling Your Tankº in the Index. It will
take a few driving trips to turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
ªFuelº in the Index. 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,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that may have developed.

2-76
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 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, see your dealer or qualified service center to
prepare the vehicle for inspection.
Oil Pressure Light
If you have a problem with
your oil, this light may stay
on after you start your
engine, or come on when
you are driving.
This indicates that oil is not going through your engine
quickly enough to keep it lubricated. The engine could
be low on oil or could have some other oil problem.
Have it fixed right away.
The oil light could also come on in the
following situations:

The light will come on briefly when you turn on
the ignition to show you that it is working properly.
(If it doesn't come on with the ignition on, you may
have a problem with the fuse or bulb. Have it fixed
right away.)

Sometimes when the engine is idling at a stop, the
light may blink on and off. This is normal.

2-77
CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have your
vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Low Oil Level Light
The engine is equipped
with an oil level
monitoring system. When
the ignition key is turned
on, the LOW OIL light
will come on briefly.
If the light does not come on briefly, have it fixed so it
will be ready to warn you if there's a problem.
If the light stays on, stop the vehicle on a level surface
and turn the engine off. Check the oil level using the
engine oil dipstick. (See ªEngine Oilº in the Index.)
If the light does not come on briefly, have the low oil
level sensor system repaired so it will be ready to warn
you if there's a problem.
The oil level monitoring system only checks oil level
during the brief period between key on and engine
crank. It does not monitor engine oil level when the
engine is running. Additionally, an oil level check is
only performed if the engine has been turned off for
a considerable period of time, allowing the oil normally
in circulation to drain back into the oil pan.

2-78 Change Oil Soon Light
The CHANGE OIL SOON
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 SOON light comes on and stays
on after you start the engine, have the oil changed.
For additional information, see ªEngine Oil, When to
Changeº in the Index. To reset the CHANGE OIL
SOON light, see ªOil Life Systemº in the Index.
Security Light
The SECURITY light will
come on when you turn the
key to START and stay on
until the vehicle starts.
It will also flash if your ignition key is too dirty or wet
for the PASS
-Key
II system to read the resistor pellet.
See ªPASS
-Key IIº in the Index.
If the resistor pellet is damaged or missing, the light
will come on.

2-79 Cruise Light
The CRUISE light comes
on whenever you set your
cruise control. See ªCruise
Controlº in the Index.
Service Vehicle Soon Light
The SERVICE VEHICLE
SOON light will come on
if you have certain
non
-emission related
vehicle problems.
These problems may not be obvious and may affect
vehicle performance or durability. Consult a qualified
dealership for necessary repairs to maintain top vehicle
performance. The light will come on briefly when your
ignition is turned on to show that it is working properly.
Low Washer Fluid Warning Light
The LOW WASH light
will come on when your
windshield washers are
working and the fluid
container is low.
The light will also come on briefly when your ignition is
turned on to show that it is working properly.
Door/Trunk Ajar Warning Light
The DOOR/TRUNK light
will come on if your trunk
or any door is not
completely closed.

2-80 Fuel Gage
United States Canada
Your fuel gage tells you about how much fuel you have left
when the ignition is on. When the indicator nears empty, you
still have a little fuel left, but you should get more soon.
Here are four things that some owners ask about. All
these things are normal and do not indicate that anything
is wrong with the fuel gage:

At the gas station, the pump shuts off before the gage
reads full.

It takes more (or less) fuel to fill up than the gage
reads. For example, the gage reads half full, but it took
more (or less) than half of the tank's capacity to fill it.
The gage pointer may move while cornering, braking
or speeding up.

The gage may not indicate empty when the ignition
is turned off.
Low Fuel Light
United States Canada
If your fuel is low, a circular light on your instrument
panel cluster will come on and stay on and a chime will
sound periodically until you add fuel.
It will also come on for a few seconds when you first
turn on the ignition as a check to show you it's working.
If it doesn't come on then, have it fixed.