2004 PONTIAC GTO engine

Malfunction Indicator Lamp
Check Engine Light
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:Modications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or replacement tires that do not match
your vehicle’s original tires 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 misfire condition has been
detected. A misfire 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 flashing and remains on steady, see “If
the Light Is On Steady” 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 “If
the Light Is On Steady” following. If the light is still
flashing, follow the previous steps, and see your dealer
for service as soon as possible.
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. 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, 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,
your dealer can 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 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.
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Oil Pressure Light
If you have a low engine
oil pressure problem, a
Check Oil message in the
trip computer display
along with this symbol will
stay on after you start
your engine, or come on
when you are driving.
This indicates that your engine is not receiving enough
oil. The engine could be low on oil, or could have
some other oil problem. Have it fixed immediately.
When the ignition is on but the engine is not running,
the light will come on as a test to show you it is working,
but the light will go out when the engine is running. If
it doesn’t come on with the ignition on, you may have a
problem with the bulb. Have it fixed right away.{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.
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Change Engine Oil Light
If the Service Engine Oil
message in the trip
computer is displayed
along with this symbol after
you start the engine, it
means that service
is required for your vehicle.
SeeScheduled Maintenance on page 6-4andEngine
Oil on page 5-13for more information.
Security Light
This light flashes when the
vehicle security system is
activated.
Fog Lamp Light
This light will come on
when the fog lamps are
in use.
The light will go out when the fog lamps are turned off.
SeeExterior Lamps on page 3-12for more information.
Highbeam On Light
This light will illuminate
when the headlamp high
beams are in use.
SeeTurn Signal/Multifunction Lever on page 3-5.
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Trip Computer
The buttons for the trip
computer are located to
the right of the gages and
the display is located
directly beneath the gages.
The basic, more commonly used functions of the trip
computer are shown following. Tap the MODE button to
scroll between the different sets of display.
You will notice that speed related displays are in the left
window, distance related displays in the center, and
fuel related windows on the right.
When the ignition is turned on, the trip computer
displays the same functions as when the ignition was
last turned off.The trip computer can be reset when AVG SPEED or
TRIP TIME are shown on the left window. To reset,
press the SET button for less than two seconds.
Resetting does not affect the Odometer, Overspeed,
Distance to Empty, Time to Arrival, Distance to Arrival,
Instantaneous Fuel, or Remaining Fuel.
Vehicle personalization is available through the trip
computer controls and display. SeeVehicle
Personalization on page 2-32.
AVG SPEED
This function shows the average speed, while the
engine is running, since the trip computer was reset.
Odometer
This function records miles travelled since the car
was built.
AVG FUEL
This function shows average fuel used since the trip
computer was reset. After resetting, a high number may
initially be shown, due to the short distance travelled
and the high fuel used when accelerating.
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TRIP TIME
This function shows the engine running time since the
trip computer was reset. If this exceeds 99 hours
and 59 minutes, the trip time is displayed in hours only.
Trip Distance
This function shows the miles travelled from the start of
a particular trip. Reset the reading to zero by pressing
and holding the SET button down for eight seconds.
FUEL USED
This function shows the total gallons/liters of fuel used
since the trip computer was reset.
TIME TO ARRIVAL
This function shows trip time to arrival in hours and
minutes, based on distance to arrival. If this exceeds
99 hours and 59 minutes, the time to arrival is displayed
in hours only.
Dist to Arrival
At the start of a trip estimate your distance to arrival.
Tap the up or down arrows until the display shows your
estimated trip distance. When you drive off, the computer
constantly updates your time to arrival, based on
changing driving speeds. You can use the up or down
arrows to adjust the miles any time this display is shown.
FUEL REMAINING
This function shows the gallons of fuel left in the fuel
tank, rounded to the nearest one gallon/liter. When the
fuel level is down to about two gallons, LO is displayed
instead of gallons.
If the Low Fuel message in the trip computer comes on
when driving, it indicates that the fuel level is low.
The Low Fuel message is displayed until the MODE
button on the trip computer switch is pressed. The trip
computer then displays its calculation of miles to
empty for 10 seconds before reverting to the original trip
computer display with a small low fuel symbol on the
left. The symbol will remain until the fuel tank is
filled above the low fuel level. If the Very Low Fuel
message in the trip computer comes on when driving, it
indicates that the fuel level is very low. The Very
Low Fuel message is displayed until the MODE button
on the trip computer switch is pressed. The trip
computer then displays its calculation of miles to empty
for 10 seconds before reverting to the original trip
computer display with a small flashing low fuel symbol
on the left. The symbol will remain until the fuel tank
is filled above the very low fuel level.
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Trip Computer Warning Messages
Cruise Control
The CRUISE light along
with the Cruise Enabled
message on the trip
computer display will come
on whenever you set
your cruise control.
SeeTurn Signal/Multifunction Lever on page 3-5.
Engine Coolant Temperature Warning:If the Engine
Temp Hot message in the trip computer display
comes on while driving, it indicates that the engine
coolant temperature is dangerously hot. You should stop
the vehicle as soon as it is safe to do so. The Engine
Temp Hot message is displayed until the MODE button
on the trip computer switch is pressed. The message
then reverts to the original trip computer display
with a small over temperature symbol on the left. The
symbol will remain until the problem is fixed. SeeEngine
Overheating on page 5-28.
Low Coolant Warning:If the Low Coolant message in
the trip computer comes on while driving, it indicates
that the engine coolant level is dangerously low.You should check the level as soon as possible, see
Engine Coolant on page 5-25. The Low Coolant
message is displayed until the MODE button on the trip
computer switch is pressed. The message then
reverts to the original trip computer display with a small
low coolant symbol on the left. The symbol will remain
until the problem is fixed.
Low Traction:If the Low Traction message appears in
the trip computer display while driving, it indicates
that the traction control system has sensed that your
vehicle requires help with road grip and that the system
is actively working to stop any wheel spin. The Low
Traction message is displayed for about one second.
The message then reverts to the original trip computer
display with a small low traction symbol on the left.
The symbol will remain as long as the low traction
situation exits. SeeTraction Control System (TCS)
on page 4-8.
Traction Off:If the Traction Ctrl Off message in the trip
computer display comes on while driving, without the
traction control being turned off by the driver, it indicates
the traction control system is not working and you
should see your vehicle dealer. The Traction Ctrl Off
message is displayed for two seconds. The message
then reverts to the original trip computer display
with a small TRAC OFF symbol on the right. The symbol
will remain until the problem is fixed. SeeTraction
Control System (TCS) on page 4-8.
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