2005 BUICK CENTURY warning light

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. Turn the ignition key to RUN with the engine off.
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

Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs rst, if only
DEX-COOL
®extended life coolant is added.
The following explains the cooling system and how to
add coolant when it is low. If there is a problem
with engine overheating or if coolant needs to be added
to the radiator, seeEngine Overheating on page 5-25.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If this coolant mixture is used, nothing
else needs to be added.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
5-22

Engine Overheating
The coolant temperature gage and the engine coolant
temperature warning light on the instrument panel
can indicate an overheated engine condition.
SeeEngine Coolant Temperature Gage on page 3-35
andEngine Coolant Temperature Warning Light on
page 3-35.
If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood.
Stay away from the engine if you see or hear
steam coming from it. Just turn it off and get
everyone away from the vehicle until it cools
down. Wait until there is no sign of steam or
coolant before you open the hood.
CAUTION: (Continued)
CAUTION: (Continued)
If you keep driving when your engine is
overheated, the liquids in it can catch re.
You or others could be badly burned. Stop
your engine if it overheats, and get out of the
vehicle until the engine is cool.
See “Overheated Engine Protection Operating
Mode” underEngine Overheating on page 5-25
for information on driving to a safe place in
an emergency.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not
be covered by your warranty. See “Overheated
Engine Protection Operating Mode” underEngine
Overheating on page 5-25for information on driving
to a safe place in an emergency.
5-25

If No Steam Is Coming From
Your Engine
An overheated engine warning can indicate a
serious problem.
If there is an overheated engine warning and you do not
see or hear any steam, the problem may not be too
serious. Sometimes the engine can get a little too hot
when the vehicle:
Climbs a long hill on a hot day.
Stops after high-speed driving.
Idles for long periods in traffic.
Tows a trailer.
If an overheated engine warning appears with no sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Adjust the heater to the highest temperature and fan
speed settings and open the window as necessary.
If the overheated engine warnings no longer exist,
you can drive. Just to be safe, drive slower for about
10 minutes. If the warnings do not come back on,
you can drive normally.
If the warning continues, and you have not stopped,
pull over, stop, and park the vehicle right away.If there is still no sign of steam, idle the engine for
three minutes while you are parked. If the warning still
exists,turn off the engine and get everyone out of
the vehicleuntil it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
The overheated engine protection operating mode allows
the vehicle to be driven to a safe place in an emergency
situation. If an overheated engine condition exists, this
protection mode alternates ring groups of cylinders to
help prevent engine damage. In this mode, there will be
a signicant loss in power and engine performance.
The engine coolant temperature gage indicator will move
to the red area, and the engine coolant temperature
warning light will come on, showing that an overheated
engine condition exists. Driving extended miles (km)
and/or towing a trailer in the overheated engine protection
mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. SeeEngine Oil on page 5-13.
5-26

Brakes
Brake Fluid
Your brake master cylinder reservoir is lled with DOT-3
brake uid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brake uid level in
the reservoir might go down. The rst is that the
brake uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the uid level goes back up. The other reason is
that uid is leaking out of the brake system. If it is, you
should have your brake system xed, since a leak
means that sooner or later your brakes will not work
well, or will not work at all.
So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you add
uid when your linings are worn, then you will have
too much uid when you get new brake linings.You should add or remove brake uid, as necessary,
only when work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system.
When your brake uid falls to a low level, your brake
warning light will come on. SeeBrake System Warning
Light on page 3-32.
What to Add
When you do need brake uid, use only DOT-3 brake
uid. Use new brake uid from a sealed container
only. SeeRecommended Fluids and Lubricants on
page 6-13.
Always clean the brake uid reservoir cap and the
area around the cap before removing it. This will help
keep dirt from entering the reservoir.
5-36

{CAUTION:
With the wrong kind of uid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake uid.
Notice:
Using the wrong uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system parts so
badly that they will have to be replaced. Do not
let someone put in the wrong kind of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged.
Be careful not to spill brake uid on your
vehicle. If you do, wash it off immediately.
SeeAppearance Care on page 5-82.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving, except when you are pushing on the
brake pedal rmly.
{CAUTION:
The brake wear warning sound means that soon
your brakes will not work well. That could lead
to an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
5-37

Fuses Usage
Blank Not Used
R/LAMPS Taillamps, License Plate Lamps
Blank Not Used
Blank Not Used
CRUISE Cruise Control
Blank Not Used
CLSTR Instrument Panel Cluster
LTR Cigarette Lighter
STOP LAMPS Stoplamps
ONSTAR OnStar
®
PRK/LGHT Parking Lamps
Blank Not Used
CRNK SIG,
BCM, CLSTRCrank Signal, Body Control Module,
Cluster, Powertrain Control Module
HVACIgnition Signal, Heating, Ventilation,
and Air Conditioning Control Head
BTSI (REGAL) Not Used
AIR BAG Air Bag
Fuses Usage
BCM PWR Body Control Module
HAZARD Hazard Warning Flashers
LH HTD SEAT Not Used
Blank Not Used
BCM ACCYIgnition Signal: Hot in ACCESSORY
and RUN, Body Control Module
Blank Not Used
LOW BLWR Low Blower
ABS Anti-Lock Brakes
TRN SIG Turn Signals, Cornering Lamps
RADIO, HVAC,
RFA, CLSTR
ALDLRadio, Heating Ventilation and
Air Conditioning Head; Remote
Keyless Entry, Cluster
HI BLWR High Blower
RH HTD SEAT Not Used
STR/WHL/
CNTRLAudio Steering Wheel Controls
WPR Windshield Wipers
5-93

A
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment............................5-90
Air Cleaner/Filter, Engine.................................5-18
Air Conditioning......................................3-18, 3-21
Airbag
Readiness Light..........................................3-31
Airbag Sensing and Diagnostic Module (SDM)......... 7-9
Airbag System................................................1-49
How Does an Airbag Restrain?......................1-55
Servicing Your Airbag-Equipped Vehicle..........1-58
What Makes an Airbag Inate?......................1-55
What Will You See After an
Airbag Inates?........................................1-56
When Should an Airbag Inate?....................1-54
Where Are the Airbags?...............................1-52
Antenna, Fixed Mast.......................................3-66
Anti-Lock Brake System (ABS)........................... 4-7
Anti-Lock Brake, System Warning Light..............3-33
Appearance Care............................................5-82
Aluminum Wheels........................................5-87
Care of Safety Belts....................................5-85
Chemical Paint Spotting...............................5-88
Cleaning Exterior Lamps/Lenses....................5-86
Fabric/Carpet..............................................5-82
Finish Care.................................................5-86
Finish Damage............................................5-88
Glass Surfaces............................................5-85Appearance Care (cont.)
Instrument Panel.........................................5-85
Interior Plastic Components...........................5-85
Leather......................................................5-84
Sheet Metal Damage...................................5-88
Tires..........................................................5-87
Underbody Maintenance...............................5-88
Vehicle Care/Appearance Materials................5-89
Vinyl..........................................................5-84
Washing Your Vehicle...................................5-86
Weatherstrips..............................................5-85
Windshield and Wiper Blades........................5-87
Ashtrays........................................................3-18
Audio System(s).............................................3-44
Audio Steering Wheel Controls......................3-63
Care of Your Cassette Tape Player................3-65
Care of Your CD Player...............................3-66
Care of Your CDs........................................3-66
Chime Level Adjustment...............................3-66
Fixed Mast Antenna.....................................3-66
Radio with Cassette and CD.........................3-53
Radio with CD............................................3-45
Setting the Time..........................................3-44
Theft-Deterrent Feature................................3-63
Understanding Radio Reception.....................3-64
Automatic Transaxle
Fluid..........................................................5-19
Operation...................................................2-21
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