engine BUICK CENTURY 2002 Owner's Guide

2-69
If the light comes on while you are driving, 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 ªTowing Your Vehicleº in
the Index.
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've
pulled off the road and stopped carefully, have
the vehicle towed for service.
When the ignition is on, the brake system warning light
will also come on when you set your parking brake. The
light will stay on if your parking brake doesn't release
fully. If it stays on after your parking brake is fully
released, it means you have a brake problem.
Anti-Lock Brake System Warning Light
United States Canada
The anti
-lock brake system warning light should come
on for a few seconds when you turn the ignition key to
RUN. If the anti
-lock brake system warning light stays
on longer than normal after you've started your engine,
turn the ignition off. Or, if the light comes on and stays
on when you're 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're driving, the anti
-lock brake system needs
service and you don't have anti
-lock brakes.
The anti
-lock brake system warning light should
come on briefly when you turn the ignition key to RUN.
If the light doesn't come on then, have it fixed so it will
be ready to warn you if there is a problem.

2-70 Enhanced Traction System Warning Light
The Enhanced
Traction System
warning light may
come on for the
following reasons:

If you turn the system off by shifting to SECOND (2)
or FIRST (1), the warning light will come on and stay
on. To turn the system back on, shift to THIRD (3) or
AUTOMATIC OVERDRIVE (
). See ªEnhanced
Traction Systemº in the Index.
If the Enhanced Traction System warning light
comes on and stays on for an extended period of
time when the system is turned on, your vehicle
needs service. Adjust your driving accordingly.

The warning light will come on when you set your
parking brake with the engine running, and it will
stay on if your parking brake doesn't release fully.
If the transaxle shift lever is in any position other
than FIRST (1) or SECOND (2) and the warning
light stays on after your parking brake is fully
released, it means there's a problem with the system.

If the traction control system is affected by an
engine
-related problem, the system will turn off
and the warning light will come on.
When this warning light is on, the system will not limit
wheel spin. Adjust your driving accordingly.

2-71 Low Traction Light
If you have the
Enhanced Traction
System, this light will
also come on when the
system is limiting
wheel spin.
You may feel or hear the system working, but this is
normal. Slippery road conditions may exist if the
low traction light comes on, so adjust your driving
accordingly. The light will stay on for a few seconds
after the Enhanced Traction System stops limiting wheel
spin. See ªEnhanced Traction Systemº in the Index.
The low traction light also comes on briefly when you
turn the ignition key to RUN. If the light doesn't come
on then, have it fixed so it will be there to tell you when
the Enhanced Traction System is active.
Engine Coolant Temperature Light
This light tells you that
your engine coolant
has overheated or your
radiator cooling fan is
not working.
The light will come on briefly when your ignition is
turned on to show you that it is working.
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.
See ªEngine Overheatingº in the Index.

2-72 Engine Coolant Temperature Gage
You have a gage that
shows the engine coolant
temperature. If the gage
pointer moves into the red
area, your engine is too hot!
That reading means the same thing as the warning light.
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.
See ªEngine Overheatingº in the Index.
Low Coolant Warning Light
If the LOW COOLANT light comes on, your system
is low on coolant and the engine may overheat. See
ªEngine Coolantº in the Index and have your vehicle
serviced as soon as you can.
The light will come on
briefly when your ignition
is turned on to show you
that it is working properly.

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.