2003 CADILLAC DEVILLE service

Manual Operation
yMODEz:Pressing the MODE switch and changing
the mode cancels automatic operation and places the
system in manual mode. Press AUTO to return to
automatic operation.
To change the current mode, select one of the following:
F(Vent):This mode directs air to the instrument
panel outlets.
*(Bi-Level):This mode directs approximately half of
the air to the instrument panel outlets, and then
directs most of the remaining air to the ¯oor outlets.
Some air may be directed toward the windshield.
In automatic operation, cooler air is directed to the upper
outlets and warmer air to the ¯oor outlets.
7(Floor):This mode directs most of the air to the
¯oor outlets with some air directed to the outboard
outlets (for the side windows) a little air directed to the
windshield.
The MODE switch can also be used to select the
¯oor/defog mode. Information on defogging and
defrosting can be found later in this section.
y9z(Fan):Press this switch to increase or
decrease the fan speed. Pressing this switch cancels
automatic operation and places the system in manual
mode. Press AUTO to return to automatic operation.
If the air¯ow seems low when the fan speed 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 3-36andPart A: Scheduled Maintenance Services on
page 6-4.
?(Recirculation):This mode keeps outside air from
coming in the vehicle. It can be used to prevent outside
air and odors from entering your vehicle or to help heat or
cool the air inside your vehicle more quickly. Press this
button to turn the recirculation mode on or off. When the
button is pressed, an indicator light will come on. The
air-conditioning compressor also comes on.
Driver's Temperature Knob:Press this knob to turn
the entire climate control system on or off. Turn this knob
clockwise or counterclockwise to manually increase or
decrease the temperature inside your vehicle.
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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 your vehicle.
·Use of non-GM approved hood de¯ectors 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.
·If the air¯ow seems low when the fan speed 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 3-36andPart A: Scheduled Maintenance
Services on page 6-4.
Rear Climate Control System
Your vehicle has a rear climate-control system that
allows the rear-seat passengers to adjust the direction
of the air¯ow, the fan speed and the temperature for the
rear-seating area. This system also works with the
main climate-control system in your vehicle.
The control panel for this system is located on the back
of the center console.
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y9z(Fan):Pressing this switch cancels automatic
operation and places the system in manual mode.
Press this switch to increase or decrease the fan speed.
Press the MODE switch until AUTO is displayed to
return to automatic operation.
yTEMPz(Temperature):Press this switch to
increase or decrease the temperature for the rear seat
passengers.
For cool air to be sent to the rear of the vehicle, the
air-conditioning system on the main climate-control
panel must be on. If it is not on, then the temperature in
the rear of the vehicle will remain at cabin temperature.
Be sure to keep the area under the front seats clear
of any objects so that the air inside of your vehicle can
circulate effectively.
Passenger Compartment Air Filter
The passenger compartment air ®lter traps most of the
pollen from the air entering your vehicle. Like your
vehicle's engine air cleaner/®lter, it may need to
be changed periodically. For how often to change the
passenger compartment air ®lter, see
Part A: Scheduled
Maintenance Services on page 6-4.
The access panel for the passenger compartment air
®lter is located under the hood near the windshield,
on the passenger's side of the vehicle.
3-36

If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.
{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not in¯ate in a crash, or they
could even in¯ate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should ¯ash for a few
seconds when you turn the ignition key to ON. If the
light doesn't come on then, have it ®xed so it will
be ready to warn you if there is a problem.
Charging System Light
When you turn the key to
ON or START, this light
will come on brie¯y
to show that the generator
and battery charging
systems are working
properly.
If this light stays on, you need service and you should
take your vehicle to the dealer at once. To save
your battery until you get there, turn off all accessories.
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Brake System Warning and Parking
Brake Indicator Light
Your vehicle's hydraulic brake system is divided into two
parts. If one part isn't working, the other part can still
work and stop you. For good braking, though, you need
both parts working well.
If the warning light comes on, there is a brake problem.
Have your brake system inspected right away.
This light should come on
brie¯y when you turn the
ignition key to ON. If it
doesn't come on
then, have it ®xed so it will
be ready to warn you if
there's a problem.
When the ignition is on, the brake system warning light
will also come on when you set your parking brake.
The light will stay on if your parking brake doesn't fully
release. If it stays on after your parking brake is
fully released, it means you have a brake problem.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you've pulled off the road and stopped
carefully, have the vehicle towed for service.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push. Or, the pedal may go closer to the
¯oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. See
Towing
Your Vehicle on page 4-31.
3-47

Anti-Lock Brake System Warning
Light
With the anti-lock brake
system, the light(s) will
come on when your engine
is started and may stay
on for several seconds.
That's normal.
If the light stays on, turn the ignition to OFF. Or, if the
light comes on when you're driving, stop as soon
as possible and turn the ignition off. Then start the
engine again to reset the system. If the light still stays
on, or comes on again while you're driving, your vehicle
needs service. If the regular brake system warning
light isn't on, you still have brakes, but you don't have
anti-lock brakes. If the regular brake system warning
light is also on, you don't have anti-lock brakes
and there's a problem with your regular brakes. See
Brake System Warning and Parking Brake Indicator
Light on page 3-47.
The anti-lock brake system warning light should come
on brie¯y when you turn the ignition key to ON. If
the light doesn't come on then, have it ®xed so it will be
ready to warn you if there is a problem.
Traction Control System (TCS)
Warning Light
This warning light should come on brie¯y when the
engine is started.
If the warning light doesn't come on then, have it ®xed
so it will be ready to warn you if there's a problem.
If it stays on, or comes on when you're driving, there
may be a problem with your traction control system and
your vehicle may need service. When this warning
light is on, the system will not limit wheel spin. Adjust
your driving accordingly.
United StatesCanada (Analog Only)
3-48

The traction control system warning light may come on
for the following reasons:
·If there's a brake system problem that is speci®cally
related to traction control, the traction control system
will turn off and the warning light will come on.
·If the traction control system is affected by an
engine-related problem, the system will turn off and
the warning light will come on.
·If the traction control system warning light comes on
and stays on for an extended period of time when the
system is turned on, your vehicle needs service.
Engine Coolant Temperature
Warning Light
This light tells you that
your engine has
overheated. As a check,
the light should come
on for a few seconds when
you start your engine.
If this light comes on and stays on, you should stop
your vehicle and turn the engine off as soon as possible.
A warning chime should also sound if this light comes on.
See
Engine Overheating on page 5-27.
3-49

Engine Coolant Temperature Gage
This gage shows the
engine coolant
temperature. If the gage
pointer moves into
the shaded area, the
engine is too hot.That reading means the same thing as the warning
light ± the engine coolant has overheated. See
Engine
Overheating on page 5-27.
.
Malfunction Indicator Lamp
Service Engine Soon Light in the
United States or Check Engine Light in
Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems. United States (Analog
Only)
Canada (Analog Only)
Digital Cluster
United StatesCanada
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