2004 BUICK CENTURY maintenance schedule

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
............................................... 1-5
Safety Belts
.............................................. 1-6
Child Restraints
.......................................1-28
Air Bag Systems
......................................1-49
Restraint System Check
............................1-58
Features and Controls..................................... 2-1
Keys
........................................................ 2-2
Doors and Locks
......................................2-10
Windows
.................................................2-15
Theft-Deterrent Systems
............................2-17
Starting and Operating Your Vehicle
...........2-18
Mirrors
....................................................2-31
OnStar
®System
......................................2-33
Storage Areas
.........................................2-34
Sunroof
..................................................2-36
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-2
Climate Controls
......................................3-18
Warning Lights, Gages and Indicators
.........3-27
Audio System(s)
.......................................3-44Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-31
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
...............5-10
Headlamp Aiming
.....................................5-49
Bulb Replacement
....................................5-51
Windshield Wiper Blade Replacement
.........5-56
Tires
......................................................5-57
Appearance Care
.....................................5-88
Vehicle Identication
.................................5-96
Electrical System
......................................5-97
Capacities and Specications
...................5-103
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-10
Index................................................................ 1
2004 Buick Century Owner ManualM

In cold weather, the system will start at reduced fan
speeds to avoid blowing cold air into the vehicle
until warmer air is available. The system will
start out blowing air at the oor but may change
modes automatically as the vehicle warms up
to maintain the chosen temperature setting. The
length of time needed for warm up will depend on
the outside temperature and the length of time
that has elapsed since the vehicle was last driven.
3. Wait for the system to regulate. This may take from
10 to 30 minutes. Then, adjust the temperature, if
necessary.
Do not cover the solar sensor located in the center
of the instrument panel, near the windshield. For
more information on the solar sensor, see
“Solar Sensor” later in this section.
Manual Operation
During daylight hours, the instrument panel brightness
control might need to be adjusted to the highest setting,
in order to see the indicator lights for the various
climate control settings.
OFF:Pressing the OFF button cancels automatic
operation and places the system in manual mode.
Press the AUTO button to return to automatic operation.TEMP (Temperature):To manually adjust the
temperature inside the vehicle, press the up arrow on
the TEMP control to raise the temperature and press the
down arrow to lower the temperature. The display will
show the selection for a few seconds, and then the
outside temperature will be displayed.
When the DUAL light indicator is on, this means the
TEMP control has set the temperature for the driver.
When the DUAL light indicator light is not on, this means
the TEMP control has set the temperature for the
entire cabin.
9FAN:Press the up arrow on the FAN control to
increase fan speed and the down arrow to decrease fan
speed. Pressing the arrows cancels the automatic
operation and places the system in manual mode. Press
the AUTO button to return to automatic operation. If
the airow seems low when the fan is at the highest
setting, the passenger compartment air lter, if
equipped, may need to be replaced. For more
information seePassenger Compartment Air Filter on
page 3-26andScheduled Maintenance on page 6-4.
AIR FLOW:This control has several settings to
control the direction of airow when the system is
not in AUTO.
To access the various modes available, continue to
press the AIR FLOW up or down arrows until the desired
mode, listed below, appears in the display.
3-22

Operation Tips
Clear away any ice, snow or leaves from the air
inlets at the base of the windshield that may
block the ow of air into the vehicle.
Use of non-GM approved hood deectors may
adversely affect the performance of the system.
Keep the path under the front seats clear of objects
to help circulate the air inside of the vehicle more
effectively.
If the vehicle has a passenger compartment air lter
and the airow seems low when the fan is at the
highest setting it may need to be replaced. For more
information, seePassenger Compartment Air
Filter on page 3-26.
Passenger Compartment Air Filter
The passenger compartment air lter is located in
the engine compartment below the air inlet grille, near
the passenger’s side windshield wiper arm.
The lter traps most of the pollen from the air entering
the air conditioning module. Like the engine’s air cleaner
lter, it may need to be changed periodically. For
information on how often to change the passenger
compartment air lter, seeScheduled Maintenance on
page 6-4.To change the passenger compartment air lter, use the
following steps:
1. Put the ignition in ACCESSORY and turn the
windshield wipers on.
2. Turn the ignition to OFF when the windshield
wipers are in the upright position.
3. Raise the hood.
4. Disconnect the windshield washer pump hose from
the fender rail and air inlet grille.
5. Remove the hood weather-strip from the
passenger’s side of the vehicle and peel it back
halfway to the center of the hood.
6. Remove the three air inlet grille retainers.
7. Remove the air inlet grille.
3-26

Oil Pressure Light
If the vehicle has a an oil
problem, this light may
stay on after the engine is
started, or come on
while you are driving.
This light indicates that oil is not going through the
engine quickly enough to keep it lubricated. The engine
could be low on oil or could have some other oil
problem. Have it xed right away.
The oil light could also come on in the following
situations:
The light will come on briey when the ignition is
turned on to show that it is working properly. If it
does not come on with the ignition on, there may be
a problem with the fuse or bulb. Have it xed
right away.
Sometimes when the engine is idling at a stop, the
light may blink on and off. This is normal.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
3-40

When You Are Ready to Leave After
Parking on a Hill
1. Apply the regular brakes and hold the pedal down
while you:
Start the engine.
Shift into a gear.
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle will need service more often when it pulls a
trailer. See.Scheduled Maintenance on page 6-4for
more information. Things that are especially important in
trailer operation are automatic transaxle uid; which
should not be overlled; engine oil, drive belt, cooling
system, and brake system. Each of these is covered
in this manual, and the Index will help you nd
them quickly. If trailering, it is a good idea to review this
information before starting on a trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-25.
4-45

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it helps to
stop ame if the engine backres. If it is not
there and the engine backres, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
Automatic Transaxle Fluid
When to Check and Change
A good time to check the automatic transaxle uid level
is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83 000 km) 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.
If the vehicle is not used under any of these conditions,
change the uid and lter at 100,000 miles
(166 000 km).
SeeScheduled Maintenance on page 6-4.
5-19

The automatic transaxle
uid dipstick handle is the
black loop located
toward the rear of the
engine. SeeEngine
Compartment Overview on
page 5-12for more
information on location.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
3. Check both sides of the dipstick, and read the
lower level. The uid level must be in the
crosshatched area.4. If the uid level is in the acceptable range, push the
dipstick back in all the way.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transaxle uid to use. SeeScheduled
Maintenance on page 6-4.
If the uid level is low, add only enough of the proper
uid to bring the level into the crosshatched area on
the dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than
one pint (0.5 L).Don’t overll.
Notice:Use of automatic transaxle uid labeled
other than DEXRON
®-III may damage your vehicle,
and the damages may not be covered by your
warranty. Always use DEXRON
®-III labeled automatic
transaxle uid.
3. After adding uid, recheck the uid level as
described under “How to Check,” earlier in
this section.
4. When the correct uid level is obtained, push the
dipstick back in all the way.
5-21

Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking each time maintenance is performed.
SeeScheduled Maintenance on page 6-4.
1. Turn on the wipers to LO.
2. Turn off the ignition while the wipers are at the
outer positions of the wiper pattern. The blades
are more accessible for removal or replacement
while in this position.
3. Pull the windshield wiper arm 3 to 4 inches
(7.5 to 10 cm) away from the windshield.
4. While holding the wiper arm away from the glass,
push the release clip from under the windshield
wiper arm connecting point and slide the blade
assembly down toward the glass to remove it from
the wiper arm.
5. Slide the new wiper blade securely on the wiper
arm until you hear the release clip click into
place. SeeNormal Maintenance Replacement Parts
on page 6-13for the type of windshield wiper
blades to use.
5-56