2009 CADILLAC DTS air conditioning

Vehicle Symbol Chart
Here are some additional symbols that may be found on
the vehicle and what they mean. For more information
on the symbol, refer to the index.
9:Airbag Readiness Light
#:Air Conditioning
!:Antilock Brake System (ABS)
g:Audio Steering Wheel Controls or OnStar®
$:Brake System Warning Light
":Charging System
I:Cruise Control
B:Engine Coolant Temperature
O:Exterior Lamps
#:Fog Lamps
.:Fuel Gage
+:Fuses
i:Headlamp High/Low-Beam Changer
j:LATCH System Child Restraints
*:Malfunction Indicator Lamp
::Oil Pressure
g:Outside Power Foldaway Mirrors
}:Power
/:Remote Vehicle Start
>:Safety Belt Reminders
7:Tire Pressure Monitor
F:Traction Control
M:Windshield Washer Fluid
iv

Climate Controls
Dual Climate Control System
The heating, cooling, and ventilation for the vehicle can
be controlled with this system.
A. Fan Control
B. Display
C. Air Delivery Mode
Control
D. Driver and
Passenger
Temperature
ControlsE. Air Conditioning
F. Outside Air or AUX
G. Recirculation
H. PASS (Passenger
Climate Control)
I. Rear Window
Defogger Dual Climate Control System
Dual Climate Control System for Vehicles with
Rear Climate Control
3-40

Automatic Operation
AUTO9(Automatic Fan):When this position is
selected on the fan control, the system adjusts the
fan speed. If the OnStar
®system is activated when
this position is selected, the climate control fan speed
will lower.
AUTO (Automatic Mode):
1. Turn the fan control to the AUTO position.
2. Turn the mode control to the AUTO position.
3. Adjust the temperature to a comfortable setting
between 68°F (21°C) and 78°F (26°C).
Choosing the coldest or warmest temperature
setting will not cause the system to heat or cool
any faster. 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
starts 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 to warm the interior depends on the
outside temperature and temperature of the vehicle.
4. Wait 20 to 30 minutes for the system to stabilize
in order for the system to regulate automatically.
Then adjust the temperature as necessary to
nd your comfort setting.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 “Sensors” later
in this section.
After the vehicle is started, the display shows the
interior temperature settings and the outside
temperature.
If the AUTO position is selected on the fan or mode
control, the system automatically controls the air
conditioning compressor. The A/C compressor will
run automatically even at cool outside temperatures
in order to dehumidify the air. The A/C indicator light
is lit when the system is operating automatically, even
at near freezing outside temperatures. Press
#on the
fan control to turn off the A/C. For improved window
clearing performance in defog or defrost modes, the
A/C compressor runs automatically.
h(AUTO RECIRCULATION):If the AUTO position is
selected on either the fan or mode control, the system
automatically controls the air inlet to supply fresh outside
air or recirculate the interior air to cool the car faster.
The light on the recirculation button will come on when
the system changes to recirculation. Outside air can be
forced by pressing
hwhen the light is lit. For vehicles
without rear climate controls, press
:to force outside
air. The next time AUTO fan or mode is selected, the air
inlet will reset back to AUTO operation.
3-41

Manual Operation
9(Off):Turns the entire climate control system off.
Outside air still enters the vehicle and is directed to
the oor. The airow direction and temperature can
be adjusted, as indicated below.
If the temperature is adjusted while the system is off,
the display will light to show the current settings.
wx(Driver’s Temperature Controls):Press the
up or down buttons next to the fan control to manually
increase or decrease the temperature inside the vehicle.
wx(Passenger’s Temperature Controls):
Press the up or down buttons next to the air delivery
mode control to manually increase or decrease the
temperature for the front passenger. If the passenger
climate control system is off, pressing one of these
buttons turns it on.
9(Fan Control):Turn clockwise or counterclockwise
to increase or decrease the fan speed. Turning this
control completely counterclockwise will turn on the
automatic fan operation. If the airow seems low
when the fan speed is at the highest setting, the
passenger compartment air lter may need to be
replaced. SeePassenger Compartment Air Filter
on page 3-48.Air Delivery Mode Control:Turn clockwise or
counterclockwise to change the current airow mode.
Select one of the following:
AUTO:Turns on the automatic delivery mode operation.
F(Vent):Air is directed to the instrument panel
outlets.
*(Bi-Level):Air is divided between the instrument
panel and the oor outlets. In automatic operation,
cooler air is directed to the upper outlets and warmer
air to the oor outlets.
7(Floor):Air is directed to the oor outlets with some
air directed to the side window outlets and the windshield.
If recirculation is selected, it only stays on for
three minutes to reduce windshield fogging.
W(Floor/Defog):This mode clears the windows of fog
or moisture. Air is directed to the oor outlets, with some
air going to the side window outlets and windshield.
When selected, the system turns off recirculation and
runs the air conditioning compressor unless the outside
temperature is at or below freezing. The recirculation
mode cannot be selected while in the oor/defog mode.
3-42

0(Defrost):This mode clears the windshield of
fog or frost more quickly. Air is directed to the windshield
and side window outlets. When selected, the system
automatically turns off recirculation and runs the air
conditioning compressor, unless the outside temperature
is at or below freezing. Recirculation cannot be selected
while in the defrost mode. Do not drive the vehicle until
all the windows are clear.
For professional vehicles, air will be allowed to ow
through the rear outlets. For quicker defrost, press the
AUX button on the front climate control system so that
the light is not lit.
#(Air Conditioning):Press to turn the air
conditioning system on or off and override the automatic
system. When in AUTO, the air conditioning compressor
comes on automatically, as necessary. To avoid window
fogging on rainy and humid days at temperatures above
freezing, run the air conditioning.
The air conditioning system removes moisture from the
air, so a small amount of water may drip under the vehicle
while idling or after turning off the engine. This is normal.
:(Outside Air):Press to turn the outside air mode
on or off. An indicator light comes on to show it is on.
Air is pulled from outside the vehicle. Pressing
?will
cancel this mode.
?(Recirculation):Press to turn the recirculation
mode on or off. An indicator light below the button
comes on to show that this mode is on. This mode
recirculates and helps to quickly cool the air inside the
vehicle. It can be used to prevent outside air and odors
from entering the vehicle. This mode cannot be selected
while in the defog or defrost modes. If you try to select the
recirculation mode, the indicator light ashes three times
and turns off.
Operation in this mode during periods of high humidity
and cool outside temperatures may result in increased
window fogging. If window fogging is experienced, select
the defrost mode.
AUX:For vehicles with a rear climate control system,
press to turn the rear climate control fan on for automatic
operation. After the AUX button is pressed, the indicator
light comes on. Press the button again to turn the
auxiliary fan off. SeeRear Climate Control System
on page 3-46.
PASS (Passenger Climate Control):Press to turn the
passenger climate control systems on or off. When the
passenger climate control system is on, the passenger
temperature setting is displayed. The temperature
selected by the front passenger also controls the rear
system air temperature unless the rear seat passengers
select their own comfort setting.
If the PASS button is pressed to turn the passenger
temperature setting off, the driver’s temperature knob
will control the temperature for the entire vehicle.
3-43

ENGINE HOT – A/C
(Air Conditioning) OFF
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-60.
To avoid added strain on a hot engine, the air
conditioning compressor automatically turns off.
When the coolant temperature returns to normal,
the air conditioning compressor turns back on.
You can continue to drive your vehicle.
If this message continues to appear, have the system
repaired by your dealer/retailer as soon as possible
to avoid damage to the engine.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon as
possible. Do not increase the engine speed above
normal idling speed. SeeEngine Overheating
on page 5-28for more information.This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle
to idle until it cools down. SeeEngine Coolant
Temperature Warning Light on page 3-59.
SeeOverheated Engine Protection Operating Mode on
page 5-30for information on driving to a safe place
in an emergency.
ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. SeeEngine Overheating on page 5-28
for more information.
This message displays when the engine has overheated.
Immediately look for a safe place to pull your vehicle
over and turn the engine off right away to avoid severe
engine damage. SeeEngine Overheating on page 5-28
andOverheated Engine Protection Operating Mode
on page 5-30. A chime also sounds when this message
is displayed.
3-75

SERVICE A/C SYSTEM
This message displays when the air delivery mode door
or the electronic sensors that control the air conditioning
and heating systems are no longer working. Have the
climate control system serviced by your dealer/retailer
if you notice a drop in heating and air conditioning
efficiency.
SERVICE BATTERY CHARGING
SYSTEM
This message displays when a problem with the
charging system has been detected. The charging
system light also displays on the instrument panel
cluster. SeeCharging System Light on page 3-56
for more information. Have your vehicle serviced by
your dealer/retailer.
SERVICE BRAKE ASSIST
This message displays if there is a problem with the
brake system. The brake system warning light and
the antilock brake system warning light may also be
displayed on the instrument panel cluster. SeeBrake
System Warning Light on page 3-56andAntilock BrakeSystem (ABS) Warning Light on page 3-57for more
information. If this happens, stop as soon as possible and
turn off the vehicle. Restart the vehicle and check for the
message on the DIC display. If the message is displayed
or appears again when you begin driving, the brake
system needs service. See your dealer/retailer as soon
as possible. SeeBrakes on page 5-33for more
information.
SERVICE BRAKE SYSTEM
This message displays if the ignition is on to inform the
driver that the brake uid level is low. Have the brake
system serviced by your dealer/retailer as soon as
possible.
SERVICE LANE DEPARTURE SYSTEM
If your vehicle has the Lane Departure Warning (LDW)
system, this message may display to indicate that the
LDW system is not working properly. If this message
remains on after continued driving, the system needs
service. See your dealer/retailer. SeeLane Departure
Warning (LDW) on page 2-49for more information.
3-80

If Steam Is Coming From The Engine
Compartment
{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. 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.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch re. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating Mode
on page 5-30for information on driving to a safe
place in an emergency.
If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no steam
can be seen or heard, 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 the overheat warning is displayed with no sign of
steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while
stopped. If it safe to do so, pull off the road, shift to
P (Park) or N (Neutral) and let the engine idle.
5-29