2001 CADILLAC DEVILLE engine coolant

2-103
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 ªEngine Overheatingº in the Index.
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 also sound when
this message is displayed.
HEADLAMPS SUGGESTED
- 23: If it's dark enough
outside and the headlamps and Twilight Sentinel

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
Daytime Running Lamps (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 Rainsense wiping
feature is on and the Twilight Sentinel is 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 also sound when
the vehicle's speed is greater than 3 mph (5 km/h).

3-4
With the automatic setting, the air conditioning
compressor automatically cycles when needed to cool
the air. In cold weather, when the system senses the need
for heat, the airflow will be directed out the floor
outlets. As the interior temperature approaches a desired
setting, the blower speed will decrease. To maintain
interior comfort, the airflow may move to the instrument
panel air outlets and floor outlets (bi
-level mode). On
bright sunny days in cold weather, the airflow may come
out of the air conditioning outlets (AC mode) to
maintain comfort and prevent stuffiness.
If your vehicle is sitting out on a hot day and you have it
set on AUTO, the air will first flow out the floor air
outlets for a few seconds. That is normal. This is to
expel hot air from the air outlets. As the air is cooled,
the airflow will move through the air conditioning
outlets. If you start your vehicle with the fan setting on
HI, it will skip the air conditioning purge.
To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the outside air
temperature, engine coolant temperature or the time
since the engine was last started. As the coolant warms
up, the blower fan speed will gradually increase and
air will flow from the heater outlets, with some airflow
to the windshield to prevent fogging under most
normal conditions.If you leave your vehicle, the system will remember the
control setting the next time you start your engine,
except for recirculation and defrost. Each ignition cycle
cancels recirculation, whereas, FRONT DEFROST will
change to automatic operation when the ignition is shut
off and then turned back on.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
AC: This setting directs airflow through the four
instrument panel outlets.
BI-LEVEL: This setting directs air into your
vehicle in two ways. Cool air is directed to the upper
portion of your body through the four instrument panel
outlets while warmed air is directed to the floor.
HEATER/DEFROST: This setting directs air to
the floor outlets and toward the windshield.
HEATER: This setting directs warmed air
through the floor outlets. Some warm air is diverted to
the windshield to minimize fogging.

3-5
DEFROST: Press this button to quickly remove
fog or frost from the windshield. This setting sends most
of the airflow to the windshield with only a small
amount to the floor outlets.
FAN SPEEDS: Press the AUTO. At this setting,
the fan speed is automatically controlled. If it is cold
outside, the blower may not run in the maximum high
fan speed right away. The system checks the
temperature of the engine coolant to assure that it is
warm enough to provide heat. When the engine coolant
is warm, the controller allows the fan to gradually
increase to a higher speed. This prevents cold air from
blowing into the passenger compartment.
OFF: Press the knob to turn the system off. Fresh air
will continue to flow through the vehicle, and the
system will try to maintain the previously set
temperature. The outside temperature will show on the
display when the system is OFF.AC: Press this button to turn the air conditioning on
and off. The system will cool and dehumidify the air
inside the vehicle. In the AUTO mode the air
conditioning compressor only operates when the system
determines it is needed. The display will show A/C OFF
when the air conditioning is off.
RECIRCULATION: Press this button to limit the
amount of fresh air entering your vehicle. This is helpful
when you are trying to cool the air quickly or limit odors
entering your vehicle. In the AUTO mode, the system
will use recirculation as necessary to cool the air.
Pressing the recirculation button will change the
operation to a manual mode and the air will recirculate
non
-stop. Press this button again to turn off the
recirculation feature.
If you notice the windows fogging, press the
recirculation button to exit the recirculation mode.

5-9
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº and ªRecreational Vehicle Towingº in
the Index.
Engine Overheating
You will find an ENGINE COOLANT HOT, IDLE
ENGINE message or an ENGINE OVERHEATED,
STOP ENGINE message on 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 ªEngine Coolant
Temperature Warning Lightº or ªEngine Coolant
Temperature Gageº in the Index.
Overheated Engine Protection
Operating Mode
Should an overheated engine condition exist and the
message ENGINE OVERHEATED, STOP ENGINE is
displayed, an overheat protection mode which alternates
firing 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). 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 indicator. See ªEngine Oilº in
the Index.

5-10 If Steam Is Coming From Your Engine
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. Just 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 your engine is
overheated, the liquids in it can catch fire.
You or others could be badly burned. Stop your
engine if it overheats, and get out of the vehicle
until the engine is cool. See ªOverheated Engine
Protection Operating Modeº in the Index.

5-11
NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not
be covered by your warranty. See ªOverheated
Engine Protection Operating Modeº in the Index.
If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.

Tow a trailer.If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Dial the temperature control to the highest heat
setting and open the windows, as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) or THIRD (3).
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for about
10 minutes. If the warning doesn't come back on,
you can drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, idle the engine for
three minutes while you're parked. If you still have the
warning, turn off the engine and get everyone out of
the vehicle until it cools down. Also, see ªOverheated
Engine Protection Operating Modeº listed previously in
this section.
You may decide not to lift the hood but to get service
help right away.

5-12
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fans
CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can injure you. Keep hands, clothing and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down.

5-13
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 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 fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.