2000 BUICK CENTURY check engine light

2-16
PASS-Key
II
Your vehicle is equipped
with the PASS
-Key II
(Personalized Automotive
Security System)
theft
-deterrent system.
PASS
-Key II is a passive
theft
-deterrent system. It
works when you insert
or remove the key from
the ignition.
PASS
-Key II uses a resistor pellet in the ignition key
that matches a decoder in your vehicle.When the PASS
-Key II system senses that someone is
using the wrong key, it shuts down the vehicle's starter
and fuel systems. For about three minutes, the starter
won't work and fuel won't go to the engine. If someone
tries to start your vehicle again or uses another key
during this time, the vehicle will not start. This
discourages someone from randomly trying different
keys with different resistor pellets in an attempt to make
a match.
The ignition key must be clean and dry before it's
inserted in the ignition or the engine may not start.
If the engine does not start and the SECURITY light
is flashing, the key may be dirty or wet. Turn the
ignition off.
Clean and dry the key. Wait about three minutes and try
again. If the starter still won't work, and the key appears
to be clean and dry, wait about three minutes and try
another ignition key. At this time, you may also want to
check the fuse (see ªFuses and Circuit Breakersº in the
Index). If the starter won't work with the other key, your
vehicle needs service. If your vehicle does start, the first
ignition key may be faulty. See your dealer or a
locksmith who can service the PASS
-Key II.

2-60 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.
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 until you turn off the ignition or
reset the system. See ªLow Tire Inflation Monitor
Systemº in the Index.

2-62
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.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.

2-63
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.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.

2-64 Low Oil Pressure Warning 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 is 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.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 you 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.

2-65 Low Oil Level Light
Your 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.
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 Oil Life Monitor,
see ªEngine Oil Life Monitorº in the Index.

4-7
Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic. This is a
mistake. Your brakes may not have time to cool between
hard stops. Your brakes will wear out much faster if you
do a lot of heavy braking. If you keep pace with the
traffic and allow realistic following distances, you will
eliminate a lot of unnecessary braking. That means
better braking and longer brake life.
If your engine ever stops while you're driving, brake
normally but don't pump your brakes. If you do, the
pedal may get harder to push down. If your engine
stops, you will still have some power brake assist. But
you will use it when you brake. Once the power assist is
used up, it may take longer to stop and the brake pedal
will be harder to push.
Anti-Lock Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent a braking skid.
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.
United States Canada
If there's a problem with the anti
-lock brake system,
this warning light will stay on. See ªAnti
-Lock Brake
System Warning Lightº in the Index.

4-30
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't 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
doesn't collect there.
Open a window just a little on the side of the
vehicle that's 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.
Recreational Vehicle Towing
Your vehicle was not designed to be towed with all four
wheels on the ground. If your vehicle must be towed,
see ªTowing Your Vehicleº in the Index.
NOTICE:
Towing your vehicle with all four wheels on the
ground will damage drivetrain components.