2000 CADILLAC DEVILLE check engine light

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PASS-Key
III
Your vehicle is equipped with the PASS-Key III
(Personalized Automotive Security System)
theft
-deterrent system. PASS-Key III is a passive
theft
-deterrent system. This means you don't have to do
anything different to arm or disarm the system. It works
when you insert or remove the key from the ignition.
Your PASS
-Key III system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference,
and (2) this device must accept any interference
received, including interference that may cause
undesired operation.
This device complies with RSS
-210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference received, including
interference that may cause undesired operation of
the device.Changes or modifications to this system by other than an
authorized service facility could void authorization to
use this equipment.
PASS
-Key III uses a radio frequency transponder in the
key that matches a decoder in your vehicle.
When the PASS
-Key III system senses that someone is
using the wrong key, it shuts down the vehicle's starter
and fuel systems. The starter will not work and fuel will
stop being delivered to the engine. Anyone using a
trial
-and-error method to start the vehicle will be
discouraged because of the high number of electrical
key codes.
When trying to start the vehicle if the engine does not
start and the SECURITY light comes on, the key may
have a damaged transponder. Turn the ignition off and
try again.
If the engine does not start, and the key appears to be
undamaged, try another ignition key. At this time, you
may also want to check the fuse (see ªFuses and Circuit
Breakersº in the Index). If the engine still does not start
with the other key, your vehicle needs service. If your
vehicle does start, the first key may be faulty. See your
dealer or a locksmith who can service the PASS
-Key III
to have a new key made.

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Warning lights come on when there may be or is a
problem with one of your vehicle's functions. As you
will see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they're working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle's functions. Often gages and
warning lights work together to let you know when
there's a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual's advice.
Waiting to do repairs can be costly
-- and even
dangerous. So please get to know your warning lights
and gages. They're a big help.
Your vehicle also has a Driver Information Center (DIC)
that works along with the warning lights and gages.
See ªDriver Information Centerº in the Index.
Safety Belt Reminder Light
When the key is turned to ON, a chime will come on
for about eight seconds to remind people to fasten
their safety belts, unless the driver's safety belt is
already buckled.
The safety belt light will
also come on and stay on
for about 20 seconds, then
it will flash for about
70 seconds.
If the driver's belt is already buckled, neither the nor
the light will come on.
If the driver's belt is already buckled, the light will
come on briefly, but the chime will not sound.

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Engine Coolant Temperature
Warning Light
This light tells you that your
engine has overheated. 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.
As a check, the light should come on for a few seconds
when you start your engine. See ªEngine Overheatingº
in the Index.
Engine Coolant Temperature Gage
Analog Cluster Digital Cluster
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, the engine is
too hot.
That reading means the same thing as the warning
light
-- the engine coolant has overheated.
See ªEngine Overheatingº in the Index.

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Malfunction Indicator Lamp
(Service Engine Soon Light in the United
States or Check Engine Light in Canada)
United States Canada
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 SERVICE ENGINE SOON or
CHECK ENGINE light comes on and a chime will
sound 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 a while, 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.

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NOTICE:
Modifications made to the engine, transaxle,
exhaust 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 the SERVICE ENGINE SOON or
CHECK ENGINE light to come on.
Modifications 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, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.
Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops flashing and remains on steady, see ªIf
the Light Is On Steadyº following.
If the light continues to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.

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If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. See ªFilling Your Tankº in the Index. The
diagnostic system can determine if the fuel cap has been
left off or improperly installed. A loose or missing fuel
cap will allow fuel to evaporate into the atmosphere. A
few driving trips with the cap properly installed should
turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Are you low on fuel?
As your engine starts to run out of fuel, your engine may
not run as efficiently as designed since small amounts of
air are sucked into the fuel line causing a misfire. The
system can detect this. Adding fuel should correct this
condition. Make sure to install the fuel cap properly. See
ªFilling Your Tankº in the Index. It will take a few
driving trips to turn the light off.Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel (see
ªFuelº in the Index). Poor fuel quality will cause your
engine not to run as efficiently as designed. You may
notice this as stalling after start
-up, stalling when you
put the vehicle into gear, misfiring, hesitation on
acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the light
to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least one
full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that may have developed.

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Emissions Inspection and Maintenance Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
SERVICE ENGINE SOON or CHECK ENGINE light is
on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on
-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is designed
to evaluate critical emission control systems during
normal driving. This may take several days of routine
driving. If you have done this and your vehicle still does
not pass the inspection for lack of OBD system
readiness, see your dealer or qualified service center
to prepare the vehicle for inspection.
Oil Pressure Light
This light tells you if there
could be a problem with
your engine oil pressure.
The light goes on when you turn your key to ON. It goes
off once you start your engine. That's a check to be sure
the light works. If it doesn't come on, be sure to have it
fixed so it will be there to warn you if something
goes wrong.
When the light comes on and stays on, it means that oil
isn't flowing through your engine properly. You could
be low on oil and you might have some other
system problem.

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CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have your
vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Security Light
For information regarding
this light, see ªTheft
Deterrent
-Systemº in
the Index.
Fog Lamp Light (If Equipped)
This light will come on
when the fog lamp button
is pressed. For more
information about the fog
lamps, see ªFog Lampsº in
the Index.