2004 CHEVROLET IMPALA fuel

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.
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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 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.
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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.
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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
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The fuel gage, when the ignition is on, tells you about
how much fuel you have left in your tank.
The gage will rst indicate empty before you are out of
fuel, and you should get more fuel as soon as
possible.
Here are four situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.
At the gas station, the fuel pump shuts off before
the gage reads full.
It takes a little more or less fuel to ll up than the
fuel gage indicated. For example, the gage may
have indicated the tank was half full, but it actually
took a little more or less than half the tank’s
capacity to ll the tank.
The gage goes back to empty when you turn off the
ignition.
The gage pointer moves while cornering, braking or
acceleration.
Message Center
The message center is located below the temperature
gage or the tachometer gage (if equipped) on the
instrument panel cluster. It gives you important safety
and maintenance facts.
Service Traction System Warning
Message
If your vehicle is equipped with the traction control
system and this message appears when you are driving,
there is a problem with your traction control system
and your vehicle is in need of service.United States
Canada
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Low Washer Fluid Warning Message
This message is displayed when the vehicle is low on
windshield washer uid.
The message is only displayed for 60 seconds at the
start of each ignition cycle. For more information
seeWindshield Washer Fluid on page 5-46.
When the ignition is turned off, this message will be
displayed again for three seconds to remind you
that your washer uid is low. Be sure to rell the
washer uid tank right away.
Low Fuel Warning Message
This message is displayed when your vehicle is low
on fuel. Four chimes will also sound.
Refer to the fuel gage for a better indication of
the amount of fuel remaining in the fuel tank. United States
CanadaUnited StatesCanada
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RESET:You can reset the AVG ECON, FUEL USED
or AVG SPEED trip computer modes by pressing
and holding this button for three seconds while you are
in the mode you wish to reset. A chime will sound to
conrm that your requested change has been made and
all the segments of the display will briey light up.
To change the display to a metric or English reading,
press the RESET and MODE buttons at the same time.
Hold them down for three seconds, and the display
will change. A chime will be heard to conrm the new
selection.
The reset button can also be used to manually calibrate
the compass. See “Manual Compass Calibration”
later in this section.
The reset button can be used to set the compass zone
variation. See “Compass Variance” later in this section.MODE:Press this button to cycle through three modes
of operation: Off, Compass/Temperature and Trip
Computer mode.
Off:No driver information is displayed in this mode
of operation.
Compass/Temperature Mode:One of eight
compass readings and the outside temperature are
displayed. If the temperature is below 38°F
(3°C), the word ICE is displayed for two minutes.
Trip Computer:Pressing the MODE button cycles
through the ve displays. Press the MODE button
after the last Trip Computer display to return
the DIC to the OFF mode.
Compass Variance
Compass variance is the difference between magnetic
north and geographic north. In some areas of the
country, the difference is great enough to cause the
compass to give false readings. If this occurs, the
compass variance must be set.
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Manual Compass Calibration
If the compass appears erratic and the calibration
symbol does not appear, you must manually put the
compass into the calibration mode.
Turn the ignition on and cycle the DIC to the
Compass/Temperature mode. Press the RESET button
for at least 10 seconds until the calibration symbol
appears and all segments of the compass display are
illuminated. A chime will sound to conrm that the
calibration mode is active. Release the button and
complete two or three 360° turns in an area free from
large metal objects. The calibration symbol will turn
off and the compass reading will be displayed. A chime
will sound to verify that the calibration is complete.
Error Displays

An error of the speed sensor or fuel sender will
cause -E- to be displayed.
In the absence of vehicle communications,
adash--isdisplayed.
If one of these error messages appear, see your dealer.
Trip Computer
There are ve trip computer displays which may be
stepped through by pushing the MODE button.
The information will appear in the following order:
AVG ECON (Average Fuel Economy):This shows the
average fuel economy since the last reset.
INST ECON (Instantaneous Fuel Economy):This
shows fuel economy for the most recent second
of driving.
RANGE (Trip Range):This shows the estimated
distance that can be traveled with the remaining fuel.
The fuel economy used to calculate range is based
on the last few hours of driving. When in a low
fuel condition, LO is displayed.
FUEL USED (Trip Fuel Used):This shows the
accumulated fuel used since the last reset.
AVG SPEED (Average Speed):This shows the
average speed since the last reset.
Resetting the Trip Computer
Press and hold the RESET button for at least three
seconds. The reset is acknowledged with all segments
of the display lit briey and a chime. A reset can
only be done in AVG ECON, FUEL USED and AVG
SPEED displays. Each setting must be reset individually.
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