2002 CADILLAC DEVILLE service

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Brake System Warning and Parking Brake
Indicator Light
Your vehicle's hydraulic brake system is divided into
two parts. If one part isn't working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on, there is a brake problem.
Have your brake system inspected right away.
This light should come on
briefly when you turn the
ignition key to ON. If it
doesn't come on then,
have it fixed so it will be
ready to warn you if there's
a problem.If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push. Or, the pedal may go closer to the floor.
It may take longer to stop. If the light is still on, have the
vehicle towed for service. See ªTowing Your Vehicleº in
the Index.
CAUTION:
Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident. If the light is still on after you've
pulled off the road and stopped carefully, have
the vehicle towed for service.

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Anti-Lock Brake System Warning Light
With the anti-lock brake
system, the light(s) will
come on when your engine
is started and may stay
on for several seconds.
That's normal.
If the light stays on, turn the ignition to OFF. Or, if the
light comes on when you're driving, stop as soon as
possible and turn the ignition off. Then start the engine
again to reset the system. If the light still stays on, or
comes on again while you're driving, your vehicle needs
service. If the regular brake system warning light isn't
on, you still have brakes, but you don't have anti
-lock
brakes. If the regular brake system warning light is also
on, you don't have anti
-lock brakes and there's a
problem with your regular brakes. See ªBrake System
Warning Lightº earlier in this section.
The anti
-lock brake system warning light should come
on briefly when you turn the ignition key to ON. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
Traction Control System Warning Light
United States Canada (Analog Only)
This warning light should come on briefly when the
engine is started.
If the warning light doesn't come on then, have it fixed
so it will be ready to warn you if there's a problem. If it
stays on, or comes on when you're driving, there may
be a problem with your traction control system and
your vehicle may need service. When this warning light
is on, the system will not limit wheel spin. Adjust your
driving accordingly.

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The traction control system warning light may come on
for the following reasons:

If there's a brake system problem that is specifically
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 ªEngine Overheatingº in the Index.

2-92
Malfunction Indicator Lamp (Service
Engine Soon Light in the United States
or Check Engine Light in Canada)
United States Canada (Analog Only)
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 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, 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 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.

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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.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.

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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.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.

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Oil Pressure Light
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.
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'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.