2004 CHEVROLET IMPALA engine

This 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 210°F (100°C) or less.
If you are pulling a load or going up hills, it is normal
for the temperature to uctuate and approach the
250°F (122°C) mark. When the gage reads greater than
250°F (122°C), the HOT COOLANT TEMP light will
be illuminated in the message center and a chime
will sound continuously. If the gage reaches the
260°F (125°C) mark, it indicates that the cooling
system is working beyond its capacity.
SeeEngine Overheating on page 5-32.Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.United States
Canada
3-37

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: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.
3-38

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 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 also 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 5-7. 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.
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 5-5. 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.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.
3-40

Fuel Gage
United States-3400 V6
Engine ClusterUnited States-3800 V6
Engine Cluster
United States-3800
Supercharged V6
Engine Cluster
Canada-3400 V6
Engine ClusterCanada-3800 V6
Engine Cluster
Canada-3800
Supercharged V6
Engine Cluster
3-42

Battery Warning Message
When the vehicle is started
this message will be
displayed for three
seconds.
If the message is displayed when the engine is running,
you may have a problem with your charging system.
If there is a problem with the charging system, four
chimes will sound when the message comes on. The
battery display will also stay on while the key is in
ON until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or
some other charging system problem. Have it checked
right away. Driving with this message on could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories.
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. SeeEngine Coolant on page 5-29,Engine Coolant
Temperature Gage on page 3-36andEngine
Overheating on page 5-32for further information.
United StatesCanada
3-45

Low Oil Pressure Message
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:
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. United States
Canada
3-46

Low Engine Oil Level Message
Your vehicle may be equipped with a low engine oil
level message.
This message is displayed for 60 seconds at the start of
each ignition cycle when the engine oil level is low.
Four chimes will also sound.
When the ignition is turned off, this message will be
displayed again for three seconds to remind you
that your engine oil level is low. Be sure to have your
vehicle serviced right away.
SeeEngine Oil on page 5-18on how to check the oil
level and for what type of oil to add.
Change Engine Oil Message
When this message comes on, it means that service is
required for your vehicle. It will appear for 60 seconds.
SeeScheduled Maintenance on page 6-4and
Engine Oil on page 5-18for more information.
Once the engine oil has been changed, the CHANGE
ENGINE OIL message must be reset. Until it is
reset, this message will be displayed for 60 seconds
each time you start the engine. For more information on
resetting the system, see “How to Reset the Change
Engine Oil Message” underEngine Oil on page 5-18. United States
CanadaUnited StatesCanada
3-47