2005 CADILLAC STS air condition

Rear Climate Control System
Your vehicle has a rear climate control system. The
base model includes air outlets in the rear of the center
console for cooling and under-seat air outlets for
heating. The temperature, quantity, and air delivery
location is controlled automatically by the front climate
control system.
Some vehicles are equipped with an optional climate
control panel for the rear passenger, located on the back
of the center console.
The left knob controls the temperature of the air to the
rear passengers. Turning the knob to the left will
make the air cooler. Turning the knob to the right will
make the air warmer.
The right knob controls the air delivery to the rear
passengers. Turning the knob all the way to the
left will shut off airow to the rear passengers.Operating with the rear air delivery off may make the
entire vehicle warm or cool less quickly. It may also
increase the air rush sound of the front system.
Y(Vent):This mode directs all the rear passenger
airow to the outlets in the console. This is the normal
position for cool down conditions.
\(Bi-Level):This mode directs airow to the console
outlets and the oor.
[(Floor):This mode directs all of the airow to the
oor. This is the normal position for warm up conditions.
The amount of airow to the rear passengers is
controlled automatically by the front climate control
system, regardless of optional equipment. Airow to the
rear system will be turned off when defrost is selected
on the front climate control panel to direct air to clear the
windshield.
Vehicles equipped with a rear climate control panel,
also, have heated rear seats. There are two buttons,
each with three indicator lights, located between the two
climate control knobs on the rear climate control
panel, to control the rear heated seats. SeeHeated
Seats on page 1-7for additional information.
Be sure to keep the area under the front seats clear of
any objects so the air in your vehicle can circulate
effectively.
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Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The Check Engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls may not
work as well, your fuel economy may not be as good,
and your engine may not run as smoothly. This could
lead to costly repairs that may not be covered by
your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of your
vehicle or the replacement of the original tires with
other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may also
result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on briey, as a check to show
you it is working, as you start the engine. If the light
does not come on, have it repaired. This light will also
come on during a malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions and
may damage the emission control system on your
vehicle. Diagnosis and service may be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
3-68

SeeOverheated Engine Protection Operating Mode on
page 5-26for information on driving to a safe place
in an emergency.
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 5-24for more information.
ENGINE HOT – AC (Air Conditioning)
OFF
This message will display when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-67.
To avoid added strain on a hot engine, the air
conditioning compressor is automatically turned off.
When the coolant temperature returns to normal, the air
conditioning compressor will turn back on. You can
continue to drive your vehicle.
If this message continues to appear, have the system
repaired by your GM dealer as soon as possible to avoid
damage to your engine.
ENGINE OVERHEATED STOP ENGINE
This message will display 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 5-24andOverheated Engine Protection
Operating Mode on page 5-26. A chime will also sound
when this message is displayed.
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 5-24for more information.
ENGINE POWER REDUCED
This message informs you that the engine power is
being reduced to protect the engine from damage. There
could be several malfunctions that might cause this
message. Have your vehicle serviced by your GM dealer
as soon as possible.
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PRESS START AND BRAKE TO START
ENGINE
When this message displays, it means that you need to
press down on the brake pedal while pressing the
start button on the electronic keyless ignition when trying
to start your vehicle. SeeStarting the Engine on
page 2-24for more information.
RADAR CRUISE NOT READY
When this message displays, it means that the Adaptive
Cruise Control system will not activate due to a
temporary condition. Your vehicle does not require
service. This message will also display when either of
the following conditions occurs:
The driver turns off the head-up display (HUD)
while the Adaptive Cruise Control is engaged.
The driver attempts to engage the Adaptive Cruise
Control while the HUD is off.
If this message appears when you attempt to activate
the system, continue driving for several minutes
and then try activating the system again.
RIGHT REAR DOOR AJAR
This symbol appears with
the RIGHT REAR DOOR
AJAR message.
When this message displays, it means that the
passenger’s side rear door was not closed completely.
You should check to make sure that the door is
closed completely.
SERVICE AC (Air Conditioning)
SYSTEM
This message will display when the electronic sensors
that control the air conditioning and heating systems are
no longer working. Have the climate control system
serviced by your GM dealer if you notice a drop
in heating and air conditioning efficiency.
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XM™ Radio Messages
Radio Display
MessageCondition Action Required
XL (Explicit Language
Channels)XL on the radio display,
after the channel name,
indicates content with
explicit language.These channels, or any others, can be blocked at a
customer’s request, by calling 1-800-852-XMXM (9696).
XM Updating Updating
encryption codeThe encryption code in the receiver is being updated, and
no action is required. This process should take no longer
than 30 seconds.
No XM Signal Loss of signal The system is functioning correctly, but the vehicle is in a
location that is blocking the XM signal. When the vehicle is
moved into an open area, the signal should return.
Loading XM Acquiring channel audio
(after 4 second delay)The audio system is acquiring and processing audio and
text data. No action is needed. This message should
disappear shortly.
Channel Off Air Channel not in service This channel is not currently in service. Tune in to another
channel.
Channel Unavail Channel no longer
availableThis previously assigned channel is no longer assigned.
Tune to another station. If this station was one of the
presets, choose another station for that preset button.
No Artist Info Artist Name/Feature
not availableNo artist information is available at this time on this channel.
The system is working properly.
No Title Info Song/Program Title
not availableNo song title information is available at this time on this
channel. The system is working properly.
3-101

California Fuel
If your vehicle is certied to meet California Emission
Standards, it is designed to operate on fuels that
meet California specications. See the underhood
emission control label. If this fuel is not available
in states adopting California emissions standards, your
vehicle will operate satisfactorily on fuels meeting
federal specications, but emission control system
performance may be affected. The malfunction indicator
lamp may turn on and your vehicle may fail a
smog-check test. SeeMalfunction Indicator Lamp on
page 3-68. If this occurs, return to your authorized GM
dealer for diagnosis. If it is determined that the
condition is caused by the type of fuel used, repairs
may not be covered by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. In most cases, you should not have to add
anything to your fuel. However, some gasolines contain
only the minimum amount of additive required to
meet U.S. Environmental Protection Agency regulations.
General Motors recommends that you buy gasolines
that are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems
due to dirty injectors or valves, try a different brand of
gasoline. Also, your GM dealer has additives that
will help correct and prevent most deposit-related
problems.
5-6

Engine Air Cleaner/Filter
The engine air cleaner/lter is in the engine
compartment on the driver’s side of the vehicle, near
the front. SeeEngine Compartment Overview on
page 5-12for more information on locating and
accessing the air cleaner/lter.
When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change after
50,000 miles (83 000 km). SeeScheduled Maintenance
on page 6-4for more information. If you are driving
in dusty/dirty conditions, inspect the lter at each engine
oil change.
How to Inspect the Engine
Air Cleaner/Filter
To inspect the air cleaner/lter remove the lter from
the vehicle and lightly shake the lter to release
loose dust and dirt. If the lter remains caked with dirt,
a new lter is required.
To inspect or replace the lter, do the following:
1. Remove the two screws located on the top of
the cover.
2. Disconnect the coolant recovery hose so that
it is not going across the top of the engine
air cleaner/lter. 4.6L V8 shown, 3.6L V6 similar
5-20

If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows, as
necessary.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can idle the engine
for three minutes while you are parked. If you still
have the warning,turn off the engine and get everyone
out of the vehicleuntil it cools down.
You may decide not to lift the hood but to get service
help right away.Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be driven to
a safe place in an emergency. Should an overheated
engine condition exist, an overheat protection mode
which alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss
in power and engine performance. A low coolant and/or
engine overheat warning will indicate that an overheat
condition exists. Driving extended miles (km) and/or
towing a trailer in the overheat protection mode should
be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss and change the oil.
SeeEngine Oil on page 5-15.
5-26