2005 BUICK CENTURY Owner's Manual

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.
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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 may
need to be replaced. For more information see
Passenger Compartment Air Filter on page 3-26and
Scheduled 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.
WINDSHIELD/FLOOR:This setting directs some of the
air to the oor outlets and some to the defroster and
side window outlets. The air-conditioning compressor will
run automatically in this setting unless the outside
temperature is below 40°F (4°C).
MID/FLOOR:This mode directs airow through both
the oor and the instrument panel outlets. A small
amount of air is directed to the windshield and the side
window outlets.
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MID (Instrument Panel):This mode directs air through
the instrument panel outlets.
FLOOR:This setting sends most of the air through the
outlets near the oor. The rest comes out of the
defroster and side window outlets.
VENT:Press this button to turn the air-conditioning
compressor on or off. The indicator light on the VENT
mode is lit when the compressor is turned off. The
interior brightness control might have to be adjusted to
the highest setting during the day in order to see
the indicator lamp.
VENT does not operate in the FRONT defrost mode.
RECIRC (Recirculation):Press this button to turn this
mode on or off. RECIRC limits the amount of outside
air coming into the vehicle and recirculates most of the
air inside your vehicle. It can be used to prevent
outside air and odors from entering the vehicle or to
quickly heat or cool the air inside the vehicle. When this
button is pressed an indicator light will come on. The
interior brightness control might have to be adjusted to
the highest setting during the day in order to see the
indicator lamp.This setting will not operate in FRONT defrost mode
and is only operational in WINDSHIELD/FLOOR mode if
the compressor is turned on.
On hot days, open the windows to let hot air inside
escape; then close them. This helps to reduce the time
it takes for the vehicle to cool down. It also helps the
system to operate more efficiently.
For quick cool down on hot days, press the AUTO
button. The system will automatically enter the
recirculation mode where the temperature will be at the
full cold position for maximum cooling.
The air-conditioning system removes moisture from the
air, so a small amount of water dripping underneath
the vehicle while it is idling or after the engine is turned
off is normal.
Operating the climate control system in the RECIRC
mode may cause fogging of the vehicle’s windows when
the weather is cold and damp. To clear the fog, select
either WINDSHIELD/FLOOR or defrost mode and
increase the speed.
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Sensors
The solar sensor on the vehicle monitors the solar heat
and the air inside of the vehicle. This information is
used to maintain the selected temperature by regulating
adjustments to the temperature, the fan speed, and
the air delivery system. The system may also supply
cooler air to the side of the vehicle facing the sun. The
recirculation mode will also be activated, as necessary.
Do not cover the solar sensor located in the center
of the instrument panel, near the windshield, or
the system will not work properly.
Passenger Control
The arrow buttons to control the temperature on the
passenger side of the vehicle are located to the right of
the PASSENGER CONTROL window. Press the
DUAL button so that the indicator light is on. Press the
right arrow to raise the temperature and press the
left arrow to lower the temperature on the passenger
side of the vehicle.
If the indicator light below the arrows is amber this
indicates that the passenger side temperature is
set the same as the driver’s side.
If the indicator light below the arrows is red, this
indicates that the passenger side temperature is
set warmer than that of the driver’s side.
If the indicator light below the arrows is blue this
indicates that the passenger side temperature is
set cooler than that of the driver’s side.
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Defogging and Defrosting
Fog on the outside of the windows is a result of high
humidity causing moisture to form and condense on the
cool window glass. This can be minimized if the climate
control system is used properly. There are two modes to
clear fog or frost from the windshield and side windows.
Use the WINDSHIELD/FLOOR mode to clear the
windows of fog or moisture and warm the passengers.
Use the defrost mode to remove fog or frost from the
windshield more quickly. For best results, clear all snow
and ice from the windshield before defrosting.
1FRONT (Defrost):This setting brings in outside air
and directs most of the air through the defrost outlet.
Some of the air also goes to the oor vents and the side
window outlets. The indicator light on the button will
come on and WINDSHIELD will be seen on the display.
To defrost the windows quickly, press the FRONT
button, set the temperature to 90°F (32°C), select a
high fan speed, and turn the DUAL button off.
To warm passengers while keeping the window
clear, push the AIR FLOW button to select
WINDSHIELD/FLOOR which will appear on the
display. Select a fan speed.The air-conditioning compressor will run automatically in
this setting unless the outside temperature is below
40°F (4°C).
Do not drive the vehicle until all windows are clear.
Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog or frost from the rear window.
=REAR:Press this button to turn the rear window
defogger on or off. It will initially turn off after about
15 minutes. If it is turned on again, it will only run for
about seven and one half minutes before turning off.
Do not drive the vehicle until all the windows are clear.
Notice:Using a razor blade or sharp object to
clear the inside rear window may damage the rear
window defogger. Repairs would not be covered
by your warranty. Do not clear the inside of the
rear window with sharp objects.
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Outlet Adjustment
Use the louvers located on the air outlets to change the
direction of the airow.
Operation Tips

Clear away any ice, snow or leaves from the air
inlets at the base of the vehicle that may block
the ow of air into your 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 your vehicle
more effectively.
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. Turn the ignition to 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.
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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.8. Replace the old air
lter by pulling up
on its tab.
9. Install a new passenger compartment air lter.
SeeNormal Maintenance Replacement Parts on
page 6-14for the type of lter to use. Make sure it
slides under the compartment retainers.
10. Reverse Steps 1 through 7.
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Warning Lights, Gages,
and Indicators
This part describes the warning lights and gages that
may be on the vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
the warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be or is a
problem with one of the vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briey when you start the
engine just to let you know they are working. If you are
familiar with this section, you should not be alarmed
when this happens.Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there is a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages
shows there may be a problem, check the section
that tells you what to do about it. Please follow this
manual’s advice. Waiting to do repairs can be
costly – and even dangerous. So please get to know
the warning lights and gages. They are a big help.
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