check engine BUICK CENTURY 2005 Owner's Guide

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Maintenance Requirements
Notice:Maintenance intervals, checks, inspections,
replacement parts and recommended uids and
lubricants as prescribed in this manual are necessary
to keep your vehicle in good working condition.
Any damage caused by failure to follow scheduled
maintenance may not be covered by warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance is
important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper uid
levels or the wrong tire ination can increase the level
of emissions from your vehicle. To help protect our
environment, and to keep your vehicle in good condition,
be sure to maintain your vehicle properly.
Using Your Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we do not know
exactly how you will drive it. You may drive very
short distances only a few times a week. Or you may
drive long distances all the time in very hot, dusty
weather. You may use your vehicle in making deliveries.
Or you may drive it to work, to do errands or in many
other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your GM Goodwrench dealer.
6-2

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 Life System on page 5-16for 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 MaintenanceIIand that you
alternate MaintenanceIand MaintenanceIIthereafter.
However, in some cases, MaintenanceIImay 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.
6-4

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-13. Reset oil life system.
SeeEngine Oil Life System on page 5-16.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-18.An Emission Control Service. See footnote †.••
Rotate tires and check ination pressures and wear. SeeTires on page 5-53.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid
as needed.••
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transaxle uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
Inspect throttle system.See footnote (j).•
6-5

(h)Change automatic transaxle uid and lter if
the vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or
delivery service.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-22for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)Check throttle system for interference or binding
and for damaged or missing parts. Replace parts
as needed. Replace any components that have high
effort or excessive wear. Do not lubricate accelerator or
cruise control cables.
(k)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the uid level checked. Add uid if needed.Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability and emission control performance of your
vehicle. Your GM Goodwrench dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-13.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil
if necessary. SeeEngine Oil on page 5-13for
further details.
Notice:It is important to check your oil regularly
and keep it at the proper level. Failure to keep your
engine oil at the proper level can cause damage
to your engine not covered by your warranty.
6-9

Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-22for further details.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the windshield
washer tank and add the proper uid if necessary.
At Least Once a Month
Tire Ination Check
Visually inspect your tires and make sure tires are
inated to the correct pressures. Do not forget to check
your spare tire. SeeTires on page 5-53for further
details. Check to make sure the spare tire is stored
securely. Push, pull and then try to rotate or turn
the spare tire. If it moves, tighten it. SeeChanging a
Flat Tire on page 5-70.
At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-24if necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The starter
should work only in PARK (P) or NEUTRAL (N).
If the starter works in any other position, contact
your GM Goodwrench dealer for service.
6-10

Automatic Transaxle Shift Lock Control
System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a
level surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-24if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the key to the RUN
position, but do not start the engine. Without
applying the regular brake, try to move the shift
lever out of PARK (P) with normal effort. If the
shift lever moves out of PARK (P), contact your
GM Goodwrench dealer for service.Ignition Transaxle Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
The key should turn to LOCK only when the
shift lever is in PARK (P).
The key should come out only in LOCK.
Contact your GM Goodwrench dealer if service
is required.
6-11

Parking Brake and Automatic Transaxle
Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged.
Make sure there is room in front of your
vehicle in case it begins to roll. Be ready to
apply the regular brake at once should the
vehicle begin to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake,
set the parking brake.
To check the parking brake’s holding ability:
With the engine running and transaxle in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Contact your GM Goodwrench dealer if service
is required.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-12

In a crash event, computer systems, such as the Air
Bag Sensing and Diagnostic Module (SDM) in your
vehicle may record information about the condition of
the vehicle and how it was operated, such as data
related to engine speed, brake application, throttle
position, vehicle speed, safety belt usage, air bag
readiness, air bag performance, and the severity of a
collision. This information has been used to improve
vehicle crash performance and may be used to improve
crash performance of future vehicles and driving
safety. Unlike the data recorders on many airplanes,
these on-board systems do not record sounds, such as
conversation of vehicle occupants.
To read this information, special equipment is needed
and access to the vehicle or the SDM is required.
GM will not access information about a crash event or
share it with others other than:
with the consent of the vehicle owner or, if the
vehicle is leased, with the consent of the lessee,
in response to an official request of police or similar
government office,
as part of GM’s defense of litigation through the
discovery process, or
as required by law.In addition, once GM collects or receives data, GM may:
use the data for GM research needs,
make it available for research where appropriate
condentiality is to be maintained and need is
shown, or
share summary data which is not tied to a
specic vehicle with non-GM organizations for
research purposes.
Others, such as law enforcement, may have access to
the special equipment that can read the information
if they have access to the vehicle or SDM.
If your vehicle is equipped with OnStar
®, please check
the OnStar®subscription service agreement or manual
for information on its operations and data collection.
Reporting Safety Defects
Reporting Safety Defects to the
United States Government
If you believe that your vehicle has a defect which could
cause a crash or could cause injury or death, you
should immediately inform the National Highway Traffic
Safety Administration (NHTSA), in addition to notifying
General Motors.
7-10

B
Battery..........................................................5-39
Run-Down Protection...................................3-17
Before Leaving on a Long Trip.........................4-22
Brake
Anti-Lock Brake System (ABS)........................ 4-7
Emergencies................................................ 4-9
Parking......................................................2-24
System Warning Light..................................3-32
Brakes..........................................................5-36
Braking........................................................... 4-6
Braking in Emergencies..................................... 4-9
Break-In, New Vehicle.....................................2-17
Bulb Replacement...........................................5-47
Back-Up Lamps...........................................5-51
Center High-Mounted Stoplamp (CHMSL)........5-49
Front Turn Signal and Parking Lamps.............5-48
Halogen Bulbs............................................5-47
Headlamp Aiming........................................5-45
Headlamps.................................................5-47
Replacement Bulbs......................................5-51
Taillamps, Turn Signal, and Stoplamps............5-50
Buying New Tires...........................................5-64
C
California Fuel.................................................. 5-6
Canadian Owners................................................ ii
Capacities and Specications............................5-96Carbon Monoxide...................2-12, 2-27, 4-26, 4-38
Care of
Safety Belts................................................5-85
Your Cassette Tape Player............................3-65
Your CD Player...........................................3-66
Your CDs ...................................................3-66
Center High-Mounted Stoplamp (CHMSL)...........5-49
Center Passenger Position, Safety Belts.............1-20
Chains, Tire...................................................5-68
Charging System Light....................................3-32
Check
Engine Light...............................................3-36
Checking Things Under the Hood......................5-10
Chemical Paint Spotting...................................5-88
Child Restraints
Child Restraint Systems...............................1-33
Infants and Young Children...........................1-30
Lower Anchorages and Top Tethers for
Children (LATCH System)..........................1-40
Older Children.............................................1-27
Securing a Child Restraint Designed for
the LATCH System...................................1-42
Securing a Child Restraint in a Center
Rear Seat Position...................................1-44
Securing a Child Restraint in a Rear
Outside Seat Position...............................1-42
Securing a Child Restraint in the Right
Front Seat Position...................................1-46
Top Strap...................................................1-37
2

D
Daytime Running Lamps/Automatic
Headlamp System.......................................3-14
Defensive Driving............................................. 4-2
Delayed Entry Lighting.....................................3-16
Delayed Exit Lighting.......................................3-17
Delayed Headlamps........................................3-13
Doing Your Own Service Work........................... 5-4
Dome Lamp...................................................3-16
Door
Locks........................................................2-10
Power Door Locks.......................................2-11
Programmable Automatic Door Locks.............2-11
Trunk Ajar Warning Light..............................3-42
Driver
Position, Safety Belt.....................................1-12
Driving
At Night.....................................................4-16
City...........................................................4-20
Defensive..................................................... 4-2
Drunken....................................................... 4-3
Freeway.....................................................4-21
Hill and Mountain Roads..............................4-24
In Rain and on Wet Roads...........................4-17
Rocking Your Vehicle to Get it Out.................4-31
Winter........................................................4-26
Dual Automatic Climate Control System.............3-21
Dual Climate Control System............................3-18
E
Electrical System
Add-On Equipment......................................5-90
Fuses and Circuit Breakers...........................5-91
Headlamp Wiring.........................................5-91
Instrument Panel Fuse Block.........................5-91
Power Windows and Other Power Options......5-91
Underhood Fuse Block.................................5-94
Windshield Wiper Fuses...............................5-91
Engine
Air Cleaner/Filter.........................................5-18
Battery.......................................................5-39
Change Engine Oil Light...............................3-40
Check and Service Engine Soon Light............3-36
Coolant......................................................5-22
Coolant Heater............................................2-20
Coolant Temperature Gage...........................3-35
Coolant Temperature Warning Light................3-35
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-27
Oil .............................................................5-13
Overheated Protection Operating Mode...........5-26
Overheating................................................5-25
Starting......................................................2-19
Enhanced Traction System (ETS)........................ 4-9
Warning Light.............................................3-34
Entry Lighting.................................................3-16
4