2003 CADILLAC DEVILLE overheating

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
3-50

ENGINE COOLANT HOT, IDLE ENGINE ± 44:This
message will appear when the engine coolant
temperature is over 262ÉF (128ÉC). Stop and allow your
vehicle to idle in PARK (P) until it cools down and the
message is removed. Do not increase engine speed
above a normal idle. If it does not cool down, turn off the
engine and have it serviced before driving it again.
Severe engine damage can result from an overheated
engine. See
Engine Overheating on page 5-27.
ENGINE HOT±AC OFF ± 16:This message displays
when the engine coolant becomes hotter than the normal
operating temperature. To avoid added strain on a hot
engine, the air conditioning compressor is automatically
turned off. When the coolant temperature returns to
normal, the A/C operation will automatically resume. You
can continue to drive your vehicle. If this message
continues to appear, have the system repaired as soon
as possible to avoid compressor damage.
ENGINE OVERHEATED, STOP ENGINE ± 42:This
message will appear when the engine has overheated.
Stop and turn the engine off immediately to avoid severe
engine damage. See
Engine Overheating on page 5-27.
A multiple chime will also sound when this message is
displayed.
ENGINE POWER REDUCED ± 41:This message
informs you that the vehicle is reducing engine power
because the transaxle is being placed in gear under
conditions that may cause damage to the vehicle's
engine, transaxle or ability to accelerate.FUEL LEVEL LOW ± 11:This message serves as a
warning that the fuel level in the tank is critically
low. Stop for fuel soon. A single chime will sound when
this message is displayed.
HEADLAMPS SUGGESTED ± 23:If it's dark enough
outside and the headlamps and Twilight Sentinel
ž
controls are off, this message will display on the DIC.
This message informs the driver that turning on the
exterior lamps is recommended even though the DRL
are still illuminated. It has become dark enough outside
to require the headlamps and/or other exterior lamps.
This message will also appear if the optional
RainsenseŸ wiping feature is on and the Twilight
Sentinel
žis off.
ICE POSSIBLE ± 13:This message appears when the
outside air temperature is cold enough to create icy
road conditions.
LEFT REAR DOOR AJAR ± 142:The left 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).
OIL PRESSURE LOW STOP ENGINE ± 35:If this
message appears while the engine is running, stop the
engine and do not operate it until the cause of low oil
pressure is corrected. Severe damage to the engine can
result. A multiple chime will sound when this message is
displayed.
3-63

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