check engine light CADILLAC DEVILLE 2004 8.G Owners Manual

PASS-Key®III Operation
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 do not have to
do anything different to arm or disarm the system. It
works when you insert or remove your key from
the ignition.
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. SeeFuses and
Circuit Breakers on page 5-108. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer who can service the PASS-Key
®
III to have a new key made.
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Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that may
be on your vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
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 briey when you start the
engine just to let you know they are 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 is 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. 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 are a big help.
Your vehicle also has a Driver Information Center (DIC)
that works along with the warning lights and gages.
SeeDriver Information Center (DIC) on page 3-62for
more information.
Instrument Panel Cluster
The instrument panel cluster is designed to let you
know at a glance how your vehicle is running. You will
know how fast you are going, how much fuel you
are using and many of the other things you will need to
know to drive safely and economically.
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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.
SeeEngine Overheating on page 5-31.
Engine Coolant Temperature Gage
United States
(Analog Only)Canada (Analog Only)
3-54

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. SeeEngine
Overheating on page 5-31.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. Digital Cluster
United StatesCanada (Analog Only)
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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 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.
Notice:Modications made to the engine,
transaxle, exhaust, intake 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 this light to come on.
Modications 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 does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions and
may damage the emission control system on your
vehicle. Diagnosis and service may be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
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.
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If the light stops ashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to ash, 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 “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
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. SeeFilling Your Tank on page 5-8. 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.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. 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, misring, 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,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x any
mechanical or electrical problems that may have
developed.
3-57

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, your GM dealer can prepare the
vehicle for inspection.
Oil Pressure Light
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
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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 or
START. It goes off once you start your engine. That is a
check to be sure the light works. If it does not come
on, be sure to have it xed so it will be there to warn you
if something goes wrong.
When the light comes on and stays on, it means that oil
is not owing through your engine properly. You
could be low on oil and you might have some other
system problem.Security Light
For information regarding
this light, see
Theft-Deterrent Systems
on page 2-19.
Fog Lamp Light
This light will come on
when the fog lamps are in
use. It will go out when the
fog lamps are turned off.
For more information about the fog lamps, see “Fog
Lamps” underExterior Lamps on page 3-17.
3-59

BATTERY VOLTAGE LOW – 6:This message will
appear when the electrical system is charging less than
10 volts or if the battery has been drained. If this
message appears immediately after starting, it is
possible that the generator can still recharge the battery.
The battery should recharge while driving but may
take a few hours to do so. Consider using an auxiliary
charger (be sure to follow the manufacturer’s
instructions) to boost the battery after returning home or
to a nal destination. If this message appears while
driving or after starting your vehicle and stays on, have
it checked immediately to determine the cause of
this problem. To help the generator recharge the battery
quickly, you can reduce the load on the electrical
system by turning off the accessories. You can monitor
battery voltage on the DIC by pressing the INFO
button. The normal range is 11.5 to 15.5 volts.
CHANGE ENGINE OIL – 82:This means that the life
of the engine oil has expired. SeeScheduled
Maintenance on page 6-4. After an oil change, the Oil
Life Indicator must be reset. SeeOil Life Indicator
on page 3-89. SeeEngine Oil on page 5-15.CHANGE TRANS FLUID – 47:This message will
appear when it is time to change the transaxle uid. See
Scheduled Maintenance on page 6-4for the proper
uid and change intervals.
CHECK BRAKE FLUID – 37:This message will display
if the ignition is in ON to inform the driver that the brake
uid level is low. Have the brake system serviced by a
technician as soon as possible. SeeBrake System
Warning and Parking Brake Indicator Light on page 3-51.
CHECK COOLANT LEVEL – 2:This message will
appear when there is a low level of engine coolant. Have
the cooling system serviced by a technician as soon
as possible. SeeEngine Coolant on page 5-27.
CHECK FUEL GAGE – 50:(Analog Cluster) This
message will appear when the fuel supply is less than
5 gallons (18.9 L) and the display is turned off. A
single chime will also sound when this message is
displayed.
CHECK GAS CAP – 61:This message will appear if
the gas cap has not been fully tightened. You should
recheck your gas cap to ensure that it is on properly.
3-66

Avoid needless heavy braking. Some people drive in
spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.Anti-lock Brake System (ABS)
Your vehicle has anti-lock brakes. ABS is an advanced
electronic braking system that will help prevent a
braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself. You
may hear a momentary motor or clicking noise while
this test is going on, and you may even notice that your
brake pedal moves a little. This is normal.
If there is a problem with
the anti-lock brake system,
this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-52.
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