1999 CADILLAC DEVILLE check engine light

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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 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 RUN or START, 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 chime
nor the light will come on.
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows AIR BAG. The system checks the
air bag's electrical system for malfunctions. The light
tells you if there is an electrical problem. The system
check includes the air bag sensors, the air bag modules,
the wiring and the crash sensing and diagnostic module.
For more information on the air bag system, see ªAir
Bagº in the Index.
This light will come on
when you start your engine,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
engine or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.

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2-72 Traction Control System Warning Light
This warning light should
come on briefly as you start
the engine. 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.
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. 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.

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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:
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 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.

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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.
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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2-76 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 RUN 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.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.

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CHANGE TRANS FLUID - 47: This message will
appear when it is time to replace the transaxle fluid. See
the Maintenance Schedule booklet for the proper fluid
and change intervals.
CHECK BRAKE FLUID
- 37: This message will
display if the ignition is in RUN to inform the driver that
the brake fluid level is low. Check the brake reservoir
level and add fluid as needed. Have the brake system
serviced by a technician as soon as possible. If the brake
warning light is on, follow the directions in that part.
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.
CHECK FUEL GAUGE
- 39: This message will
appear when the fuel supply is less than four gallons
(15.2 L) and the display is turned off (digital clusters
only). 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's fully tightened.CHECK OIL LEVEL
- 36: For correct operation of
the low oil sensing system, your vehicle should be on a
level surface. A false CHECK OIL LEVEL message
may appear if the vehicle is parked on grades. The oil
level sensing system does not check for actual oil level
if the engine has been off for a short period of time, and
the oil level is never sensed while the engine is running.
If the CHECK OIL LEVEL message appears, and your
vehicle has been parked on level ground with the engine
off for at least 30 minutes, the oil level should be
checked by observing the oil dipstick. Prior to checking
the oil level, be sure the engine has been off for five
minutes and your vehicle is on a level surface. Then
check the dipstick and add oil if necessary. See
ªEngine Oilº in the Index.
CHECK WASHER FLUID
- 25: This message will
appear for several seconds indicating that you need
washer solvent.
CRUISE ENGAGED
- 43: This message will appear for
a few seconds when you select a speed at which to cruise.
DOOR AJAR
- 141: A door other than the driver's
door is open or ajar when this message appears. The
vehicle's engine must be running 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
5 mph (8 km/h).

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NOTICE:
Before you add any sound equipment to your
vehicle
-- like a tape player, CB radio, mobile
telephone or two
-way radio -- be sure you can
add what you want. If you can, it's very
important to do it properly. Added sound
equipment may interfere with the operation of
your vehicle's engine, radio or other systems, and
even damage them. Your vehicle's systems may
also interfere with the operation of sound
equipment that has been added improperly.
So, before adding sound equipment, check with
your dealer and be sure to check Federal rules
covering mobile radio and telephone units.
Care of Your Cassette Tape Player
A tape player that is not cleaned regularly can cause
reduced sound quality, ruined cassettes or a damaged
mechanism. Cassette tapes should be stored in their
cases away from contaminants, direct sunlight and
extreme heat. If they aren't, they may not operate
properly or may cause failure of the tape player.Your tape player should be cleaned regularly after every
50 hours of use. Your radio may display CLN or
CLEAN TAPE to indicate that you have used your tape
player for 50 hours without resetting the tape clean
timer. If this message appears on the display, your
cassette tape player needs to be cleaned. It will still play
tapes, but you should clean it as soon as possible to
prevent damage to your tapes and player. If you notice a
reduction in sound quality, try a known good cassette to
see if it is the tape or the tape player at fault. If this other
cassette has no improvement in sound quality, clean the
tape player.
The recommended cleaning method for your cassette
tape player is the use of a scrubbing action,
non
-abrasive cleaning cassette with pads which scrub
the tape head as the hubs of the cleaner cassette turn.
The recommended cleaning cassette is available through
your dealership (GM Part No. 12344789).
When using a scrubbing action, non
-abrasive cleaning
cassette, it is normal for the cassette to eject because
your unit is equipped with a cut tape detection feature
and a cleaning cassette may appear as a broken tape. To
prevent the cleaning cassette from being ejected, use the
following steps.
1. Turn the ignition to RUN or ACCESSORY.
2. Turn the radio off.

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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're driving, brake
normally but don't 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 Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). 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's a problem with the
anti
-lock brake system, this
warning light will stay on.
See ªAnti
-Lock Brake
System Warning Lightº in
the Index.