2003 CADILLAC DEVILLE heating

PASSENGER DOOR AJAR ± 141:The right front
passenger's door is open or ajar when this message
appears. The ignition must be in ON and the transaxle
not in PARK (P) for this message to display. A chime
will sound if the vehicle's speed is greater than
3 mph (5 km/h).
RIGHT REAR DOOR AJAR ± 143:The right rear door
is open or ajar when this message appears. The
ignition must be in ON and the transaxle not in PARK (P)
for this message to display. A chime will sound if the
vehicle's speed is greater than 3 mph (5 km/h).
SERVICE AC SYSTEM ± 14:This message appears
when the electronic sensors that control the air
conditioning and heating systems are no longer working.
Have the climate control system serviced if you notice
a drop in heating and air conditioning efficiency.
SERVICE AIR BAG ± 83:There is a problem with the
air bag system when this message appears. Let
only a quali®ed technician work on your vehicle. Have
your vehicle serviced by your dealership immediately.
SERVICE CHARGING SYS ± 102:This message
will display when a problem with the charging system
has been detected. Have your vehicle serviced at
your dealership.SERVICE ELECTRICAL SYS ± 106:This message will
display if an electrical problem has occurred within
the Powertrain Control Module (PCM) or the ignition
switch. Have your vehicle serviced by your dealership.
SERVICE FUEL SYSTEM ± 101:The Powertrain
Control Module (PCM) has detected a problem within
the fuel system when this message appears. Have your
vehicle serviced by your dealership.
SERVICE IDLE CONTROL ± 107:A problem with the
idle control has occurred when this message displays.
Have your vehicle serviced by your dealership.
SERVICE STABILITY SYS ± 54:If you ever see the
SERVICE STABILITY SYS message, it means
there may be a problem with your stability enhancement
system. If you see this message, try to reset the
system (stop, turn off the engine, then start the engine
again). If the SERVICE STABILITY SYS message
still comes on, it means there is a problem. You should
see your dealer for service. Reduce your speed and
drive accordingly. A single chime will also sound when
this message is displayed.
SERVICE STEERING ± 127:This message is displayed
when a problem has been detected in the magnetic
speed variable assist steering system. If message
comes on, service is required.
3-64

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need a
different turn signal ¯asher and/or extra wiring. Check
with your dealer. The arrows on your instrument
panel will ¯ash whenever you signal a turn or lane
change. Properly hooked up, the trailer lamps will also
¯ash, telling other drivers you're about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ¯ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It's
important to check occasionally to be sure the trailer
bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
On long uphill grades, reduce speed to 45 to 50 mph
(70 to 90 km/h) and avoid prolonged use of SECOND (2)
gear and engine speeds above 3800 rpm.
Climbing grades steeper than four percent at
temperatures above 90É F (32É C) with a loaded vehicle
and trailer is not recommended. The cooling system
may temporarily overheat. See
Engine Overheating on
page 5-27.
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 you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but do not shift into
PARK (P).
2. Have someone place chocks behind the trailer
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 shift into PARK
(P) ®rmly and apply your parking brake.
5. Release the regular brakes.
4-39

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
·start your engine
·shift into a gear, and
·make sure the parking brake has released.
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
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transaxle ¯uid (don't over®ll),
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 you're trailering,
it's a good idea to review this information before you
start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-27.
4-40

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under
the Hood....................................................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-19
Automatic Transaxle Fluid..............................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Cooling System............................................5-30Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-43
Headlamp Aiming...........................................5-49
Headlamp Horizontal Aiming...........................5-50
Headlamp Vertical Aiming..............................5-50
Bulb Replacement..........................................5-53
Halogen Bulbs..............................................5-53
Headlamps..................................................5-53
Front Turn Signal, Sidemarker, Parking and
Cornering Lamps.......................................5-57
Center High-Mounted Stoplamp (CHMSL).........5-58
Taillamps, Turn Signal, and Stoplamps............5-58
Replacement Bulbs.......................................5-58
Windshield Wiper Blade Replacement..............5-59
Tires..............................................................5-60
In¯ation Ð Tire Pressure...............................5-61
Tire Pressure Monitor System.........................5-62
Tire Inspection and Rotation...........................5-64
When It Is Time for New Tires.......................5-65
Buying New Tires.........................................5-66
Section 5 Service and Appearance Care
5-1

Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Giving freezing protection down to-34É F-37É C.
·Give boiling protection up to 265É F (129É C).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
Notice:When adding coolant, it is important that
you use only DEX-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50,000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new vehicle
warranty.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOLžcoolant which won't damage
aluminum parts. If you use this coolant mixture,
you don't need to add anything else.
5-24

Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the surge tank,but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
When replacing the pressure cap, make sure the arrow
lines up with the tube.
Coolant Surge Tank Pressure Cap
Notice:Your pressure cap is a pressure-type
cap and must be tightly installed to prevent coolant
loss and possible engine damage from overheating.
See ªCapacities and Speci®cationsº for more
information.
Engine Overheating
You will ®nd an ENGINE COOLANT HOT, IDLE
ENGINE message or an ENGINE OVERHEATED,
STOP ENGINE message displayed in the Driver
Information Center (DIC). You will also hear a chime.
There is also an engine temperature warning light and/or
gage on the instrument panel cluster. See
Engine
Coolant Temperature Warning Light on page 3-49andEngine Coolant Temperature Gage on page 3-50.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
message ENGINE OVERHEATED, STOP ENGINE is
displayed, 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. This operating mode allows your
vehicle to be driven to a safe place in an emergency;
you may drive up to 50 miles (80 km). 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, change the oil and reset the oil
life system. See ªEngine Oilº in the Index.
5-27

A low coolant level should be indicated by a CHECK
COOLANT LEVEL message on the Driver Information
Center. If it is, you may have a leak at the pressure cap
or in the radiator hoses, heater hoses, radiator, water
pump or somewhere else in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them. If you
do, you can be burned.
Don't run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine ®re, and you could be
burned. Get any leak ®xed before you drive the
vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine is overheating, both fans should be
running. If they aren't, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index for information on driving to a
safe place in an emergency.
Notice:When adding coolant, it is important that
you use only DEX-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50 000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new vehicle
warranty.
How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn't at the proper level 4.5 inches
(11.4 cm) below the top of the ®ller neck), add a
50/50 of
clean, drinkable waterand DEX-COOLžcoolant
at the coolant surge tank, but be sure the cooling
system, including the coolant surge tank pressure cap,
is cool before you do it. See
Engine Coolant on
page 5-24for more information.
5-31

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your Cadillac Warranty booklet for details.
{CAUTION:
·Poorly maintained and improperly used
tires are dangerous.
·Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See ªLoading Your
Vehicleº in the Index.
CAUTION: (Continued)
CAUTION: (Continued)
·
Underin¯ated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
·Overin¯ated tires are more likely to be cut,
punctured or broken by a sudden
impactÐ such as when you hit a pothole.
Keep tires at the recommended pressure.
·Worn, old tires can cause accidents.
If your tread is badly worn, or if your tires
have been damaged, replace them. See
ªIn¯ation ± Tire Pressureº in this section
for in¯ation pressure adjustment for higher
speed driving.
5-60