2005 BUICK CENTURY heating

After initially moving the shift lever out of and back into
PARK (P), each additional shift cycle will advance
the programming from the current mode to the next
operating mode. If cycled beyond Mode 4, the vehicle
will enter operating Mode 1.
Disconnecting the vehicle’s battery for up to a year will
not affect the programmed mode.
Lockout Protection
The power door locks will not work if the key is in the
ignition and a door is open. You can override this feature
by holding the driver’s side power door lock switch for
more than three seconds.
Leaving Your Vehicle
If you are leaving the vehicle, take your key, open your
door and set the locks from inside or with the remote
keyless entry transmitter. Then get out and close
the door.
Trunk
{CAUTION:
It can be dangerous to drive with the trunk lid
open because carbon monoxide (CO) gas can
come into your vehicle. You can not see or
smell CO. It can cause unconsciousness and
even death. If you must drive with the trunk lid
open or if electrical wiring or other cable
connections must pass through the seal
between the body and the trunk lid:
Make sure all other windows are shut.Turn the fan on your heating or cooling
system to its highest speed and select the
control setting that will force outside air
into your vehicle. See Climate Control
System in the Index.
If you have air outlets on or under the
instrument panel, open them all the way.
SeeEngine Exhaust on page 2-27.
2-12

Ashtrays and Cigarette Lighter
The center front ashtray is located below the instrument
panel comfort controls.
To remove the ashtray, open the storage door.
Then open the ashtray lid, lift up and pull it out.
Notice:Holding a cigarette lighter in while it is
heating will not allow the lighter to back away from
the heating element when it is hot. Damage from
overheating may occur to the lighter or heating
element, or a fuse could be blown. Do not hold a
cigarette lighter in while it is heating.
Push the lighter to use it. When the heating element is
hot, the lighter will pop back out by itself.
Notice:If you put papers or other ammable items
in the ashtray, hot cigarettes or other smoking
materials could ignite them and possibly damage
your vehicle. Never put ammable items in
the ashtray.
Climate Controls
Dual Climate Control System
Your vehicle may have this climate control system.
The heating, cooling, and ventilation for the vehicle can
be controlled with it.
Manual Operation
To change the current mode, select one of the following
settings on the right knob.
MAX (Maximum Air-Conditioning):This mode
recirculates much of the air inside the vehicle and sends it
through the instrument panel outlets. The air-conditioning
compressor will run automatically in this setting unless
the outside temperature is below 40°F (4°C).
3-18

Dual Automatic Climate
Control System
Your vehicle may have this climate control system.
The heating, cooling and ventilation can be controlled
with it.
Automatic Operation
AUTO (Automatic):Press the AUTO button for
automatic control of the inside temperature, the air
delivery mode and the fan speed. There might be a
delay of two to three minutes before the fan comes on
when the automatic operation is used in cold weather.
For the automatic system to function, the temperature
must be set between 61°F (16°C) and 89°F (31°C).1. Adjust the temperature to a comfortable setting.
2. Press the AUTO button.
Choosing the coldest or warmest temperature
setting will not cause the system to heat or cool
any faster.
If the system is set at the warmest temperature
setting, 90°F (32°C), hot air will be directed to the
oor, the fan will increase to the highest speed, and
the system will remain in manual mode at that
temperature. The system will not return to automatic
until the temperature setting is lowered.
If the system is set at the coldest temperature
setting, 60°F (15°C), cold interior air will be
recirculated through the air panel outlets, and the
fan will increase to the highest speed. The system
will not return to automatic until the temperature
is raised.
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.
3-21

Engine Coolant Temperature
Warning Light
This light indicates that
the engine coolant has
overheated or the radiator
cooling fan is not working.
The light will come on briey when the ignition is turned
on to show that it is working.
If the vehicle has been operating under normal driving
conditions, pull off the road, stop the vehicle and turn off
the engine as soon as possible. SeeEngine Overheating
on page 5-25.
Engine Coolant Temperature Gage
The vehicle has a gage
that shows the engine
coolant temperature. If the
gage pointer moves into
the red area, the engine
is too hot.
This reading indicates the same thing as the warning
light. It means that the engine coolant has overheated.
If the vehicle has been operating under normal
driving conditions, pull off the road, stop the vehicle and
turn off the engine as soon as possible. SeeEngine
Overheating on page 5-25.
3-35

Turn Signals When Towing a Trailer
When towing a trailer, the vehicle may need a different
turn signal asher and/or extra wiring. Check with your
dealer. The arrows on the instrument panel will ash
whenever signaling a turn or lane change. Properly
hooked up, the trailer lamps will also ash, telling other
drivers you are about to turn, change lanes or stop.
When towing a trailer, the arrows on the instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. You may think drivers behind you
are seeing your signal when they are not. It is important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long hill or steep downgrade. If the vehicle is not
shifted down, the brakes might have to be used so much
that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of engine and transaxle overheating.
If towing a trailer, you may want to drive in THIRD (3)
instead of AUTOMATIC OVERDRIVE (
X). Shift to
a lower gear as needed.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if the rig ever has to be parked on a hill, here is
how to do it:
1. Apply the regular brakes, but do not shift into
PARK (P) yet.
2. Have someone place chocks under the
trailer’s wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply the parking
brake, and shift to PARK (P).
5. Release the regular brakes.
4-43

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. SeeScheduled 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.
4-44

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-24
Engine Overheating.......................................5-25
Overheated Engine Protection
Operating Mode........................................5-26
Cooling System............................................5-27Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
Headlamp Aiming...........................................5-45
Bulb Replacement..........................................5-47
Halogen Bulbs..............................................5-47
Headlamps..................................................5-47
Front Turn Signal and Parking Lamps................5-48
Center High-Mounted Stoplamp (CHMSL).........5-49
Taillamps, Turn Signal, and Stoplamps............5-50
Back-Up Lamps............................................5-51
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-53
Tire Sidewall Labelling...................................5-54
Tire Terminology and Denitions.....................5-57
Ination - Tire Pressure.................................5-60
Tire Pressure Monitor System.........................5-61
Tire Inspection and Rotation...........................5-63
When It Is Time for New Tires.......................5-64
Buying New Tires.........................................5-64
Uniform Tire Quality Grading..........................5-65
Wheel Alignment and Tire Balance..................5-67
Section 5 Service and Appearance Care
5-1

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