2003 CHEVROLET MONTE CARLO check engine light

Passlockž
Your vehicle is equipped with the Passlockž
theft-deterrent system.
Passlock
žis a passive theft-deterrent system. Passlockž
enables fuel if the ignition lock cylinder is turned with
a valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, fuel is disabled and
the engine will not start.
During normal operation, the SECURITY message will
be displayed after the key is turned to the ON ignition
position. See
Security Message on page 3-49.
If the engine stalls and the SECURITY message
¯ashes, wait until the light stops ¯ashing before trying to
restart the engine.
If the engine is running and the SECURITY message
comes on, you will be able to restart the engine if
you turn the engine off. However, your Passlock
ž
system is not working properly and must be serviced by
your dealer. Your vehicle is not protected by Passlockž
at this time. You may also want to check the fuse.
SeeFuses and Circuit Breakers on page 5-91. See your
dealer for service.
In an emergency, contact Chevrolet Roadside
Assistance. See
Roadside Assistance Program on
page 7-5for more information.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle doesn't need an elaborate
ªbreak-in.º But it will perform better in the long run
if you follow these guidelines:
·Don't drive at any one speed Ð fast or
slow Ð for the ®rst 500 miles (805 km).
Don't make full-throttle starts.
·Avoid making hard stops for the ®rst 200 miles
(322 km) or so. During this time your new
brake linings aren't yet broken in. Hard stops
with new linings can mean premature wear and
earlier replacement. Follow this breaking-in
guideline every time you get new brake linings.
·Don't tow a trailer during break-in. See ªTowing
a Trailerº in the Index for more information.
2-16

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 brie¯y 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 may also have a Driver Information Center
(DIC) that works along with the warning lights and
gages. See
Driver Information Center (DIC) on
page 3-52.
3-30

Engine Coolant Temperature GageThis gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During the majority of the operation, the
gage will read 210ÉF (100ÉC) or less.
If you are pulling a load or going up hills, it is normal for
the temperature to ¯uctuate and approach the 250ÉF
(122ÉC) mark. When the gage reads greater than 250ÉF
(122ÉC), the HOT COOLANT TEMP light will be
illuminated in the message center and a chime will
sound continuously. If the gage reaches the 260ÉF
(125ÉC) mark, it indicates that the cooling system is
working beyond its capacity.
See
Engine Overheating on page 5-29.
Malfunction Indicator Lamp
Check Engine Light
United States-3400 V6
Engine ClusterUnited States-3800 V6
Engine Cluster
Canada-3400 V6 Engine
ClusterCanada-3800 V6 Engine
ClusterUnited StatesCanada
3-38

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 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:Modi®cations 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.
Modi®cations 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 FlashingÐ A mis®re condition has been
detected. A mis®re increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
·Light On SteadyÐ An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
3-39

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-4. 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, mis®ring, 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.
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 to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the 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.
3-41

Oil Pressure Indicator Light
The oil pressure indicator
tells you if you have the
correct oil pressure in your
engine to operate your
vehicle.
Under normal conditions the indicator should read
slightly above the half way point.
If your oil pressure falls too low, the indicator will read
at the low setting in the red zone.This message is displayed in the message center when
the engine oil pressure is low. A chime will sound
continuously, also.
If this occurs, you should have your vehicle serviced
immediately.
{CAUTION:
Don't 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:Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty. 3800 V6 Engine
United StatesCanada
3-42

Hot Coolant Temperature Warning
Message
This message is displayed when the cooling
system temperature gets hot. A chime will sound
continuously, also.
Check the coolant temperature gage and the coolant
level. See
Engine Coolant on page 5-26,Engine Coolant
Temperature Gage on page 3-38andEngine
Overheating on page 5-29for further information.
Low Oil Pressure Message
This message is displayed when the engine oil pressure
is low. A chime will sound continuously, also. See Oil
Pressure Indicator Light on page 3-42. United States
Canada
United StatesCanada
3-46

Avoid needless heavy braking. Some people drive
in spurts Ð heavy acceleration followed by heavy
braking Ð 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 Brake System (ABS)
Your vehicle may have anti-lock brakes. ABS is an
advanced electronic braking system that will help
prevent a braking skid.
If your vehicle has anti-lock
brakes, this warning light
on the instrument panel will
come on brie¯y when
you start your vehicle.When you start your engine, or when you 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 or pulses a little. This is normal.
Let's say the road is wet and you're driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here's what
happens with ABS:
4-6