2004 CHEVROLET SILVERADO 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 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.
3-48

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 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 5-9. The
diagnostic system can determine if the fuel cap hasbeen 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.
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.
3-49

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.
Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is
running. Canadian vehicles indicate pressure in
kPa (kilopascals).
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.United States
Canada
3-50

A reading in the low pressure zone may be caused by a
dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon as
possible. SeeOil Pressure LowunderDIC Warnings
and Messages on page 3-64andEngine Oil on
page 5-20.
{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.
Cruise Control Light
The cruise light comes on
whenever you set your
cruise control. See “Cruise
Control” underTurn
Signal/Multifunction Lever
on page 3-7.
Four-Wheel-Drive Light
The four-wheel drive
indicator will light up when
you shift a manual
transfer case into
four-wheel drive and the
front axle engages.
Some delay between shifting and the indicator’s
lighting is normal.
SeeFour-Wheel Drive on page 2-36for
more information.
3-51

Here are some 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.
If you have a diesel engine, see “Fuel Gage” in the
Diesel Engine Supplement.
Low Fuel Warning Light
The light next to the fuel gage will come on briey when
you are starting the engine.
This light comes on when the fuel tank is low on fuel.
To turn it off, add fuel to the fuel tank. SeeFuel on
page 5-5.
Driver Information Center (DIC)
The DIC display is located on the instrument panel
cluster above the steering wheel. The DIC can display
information such as the trip odometer, fuel economy and
personalization features.
A (Trip Information):This button will display the
odometer, personal trip odometer, business trip
odometer, hourmeter, annual log and the timer.
B (Fuel Information):This button will display the
current range, average fuel economy, instant fuel
economy and engine oil life.
3-53

C (Personalization):This button will change personal
options available on your vehicle.
D (Select):This button resets certain functions and
turns off or acknowledges messages on the DIC.
If your vehicle is not equipped with the DIC steering
wheel buttons you will not have all of the features listed
above, and you will turn off, or acknowledge DIC
messages by using the trip odometer reset stem located
on the instrument panel cluster.
DIC Operation and Displays
The DIC comes on when the ignition is on. After a short
delay the DIC will display the current driver (1 or 2)
and the information that was last displayed before the
engine was turned off.
If a problem is detected, a warning message will appear
on the display. Pressing any of the four buttons will
acknowledge (clear) most current warnings or service
messages. Some warnings that cannot be
acknowledged (cleared) are: ENGINE OVERHEATED,
OIL PRESSURE LOW, REDUCED ENGINE POWER,
TRANS HOT IDLE ENGINE. These warnings must
be dealt with immediately and therefore cannot
be cleared until the problem has been corrected.
The DIC has different modes which can be accessed by
pressing the four buttons on the DIC. These buttons are
trip information, fuel information, personalization and
select. The button functions are detailed in the following.
Trip Information Button
Press the trip information button to scroll through the
ODOMETER, PERSONAL TRIP ON/OFF, BUSINESS
TRIP ON/OFF, HOURMETER, ANNUAL LOG and
TIMER. If the personal trip and/or the business trip are
set to ON, you will also be able to scroll through
more messages. See “Personal Trip” and “Business
Trip” next for more information.
If your vehicle is not equipped with the DIC steering
wheel buttons you can select the trip information
by pressing the trip odometer reset stem on the
instrument panel cluster.
Personal Trip
Turn PERSONAL TRIP on or off by pressing the
select button. When it is on, you will also be able to
scroll through the following by pressing the trip
information button:
PERSONAL: XXXXXX.X MI — This shows the
current distance traveled since the last reset for the
personal trip odometer in either miles or kilometers.
PERSONAL: XXXX.X GAL — This shows the
amount of fuel used for the personal trip.
PERSONAL: XX.X MPG— This shows how
many miles per gallon of fuel your vehicle is getting
for the personal trip based on current and past
driving conditions.
3-54

PERSONAL: XXX.X AVG MPH — This shows the
vehicle’s average speed for the personal trip.
PERSONAL: % ANNUAL — This shows the ratio of
personal trip miles to annual miles as a percent.
You can reset the personal trip odometer by pressing
and holding the trip odometer reset stem.
Business Trip
Turn BUSINESS TRIP on or off by pressing the
select button. When it is on, you will also be able to
scroll through the following by pressing the trip
information button:
BUSINESS: XXXXXX.X MI — This shows the
current distance traveled since the last reset for the
business trip odometer in either miles or kilometers.
BUSINESS: XXXX.X GAL — This shows the
amount of fuel used for the business trip.
BUSINESS: XX.X MPG — This shows the amount
of fuel used for the business trip.
BUSINESS: XXX.X AVG MPH — This shows the
vehicle’s average speed for the business trip.
BUSINESS: % ANNUAL — This shows the ratio of
business trip miles to annual miles as a percent.To reset personal or business trip information press and
hold the select button for approximately one second
while in one of the personal or business trip modes. This
will reset all of the information for the personal or
business trip.
You can also reset the PERSONAL: XX MI, or
BUSINESS: XX MI while they are displayed by pressing
the reset stem on the cluster. If you press and hold
the reset stem or select button for four seconds,
the display will show the distance traveled since the last
ignition cycle for the personal or business trip.
Odometer
Press the trip information button until ODOMETER
appears on the display. This shows the total distance
the vehicle has been driven in either miles or kilometers.
Pressing the reset stem located on the instrument
cluster with the vehicle off will also display the odometer.
Hourmeter
Press the trip information button to scroll to the
hourmeter. The hourmeter shows the total number of
hours the engine has run. Pressing and holding the reset
stem for about 4 seconds on the instrument cluster
will also display the hourmeter after the odometer
is displayed when the vehicle is off.
3-55

Instant Fuel Economy
Press the fuel information button until INST ECON
appears in the display. Instant fuel economy is how
many miles per gallon your vehicle is getting at
the particular moment in time. The instant fuel economy
cannot be reset.
GM Oil Life System
Press the fuel information button until ENGINE OIL LIFE
appears in the display. The GM Oil Life System shows
an estimate of the oil’s remaining useful life. It will show
100% when the system is reset after an oil change. It
will alert you to change your oil on a schedule consistent
with your driving conditions.
Always reset the engine oil life after an oil change. To
reset the Oil Life System use the fuel button to reach the
ENGINE OIL LIFE screen and then press and hold
the select button for ve seconds while ENGINE OIL
LIFE is displayed. OIL LIFE RESET will appear on
the display for 10 seconds to let you know the system
is reset.
The DIC does not replace the need to maintain your
vehicle as recommended in the Maintenance Schedule
in this manual. SeeEngine Oil on page 5-20.
Personalization Button
You can program certain features to a preferred setting
for up to two people. Press the personalization button
to scroll through the following personalization features.
All of the personalization options may not be available
on your vehicle. Only the options available will be
displayed on your DIC.
If your vehicle is not equipped with the DIC steering
wheel buttons you will not have any of the following
personalization options except for DISPLAY
LANGUAGE. See DISPLAY LANGUAGE later in this
section for more information.
AUTOMATIC LOCKING
AUTOMATIC UNLOCKING
DELAYED LOCKING
REMOTE LOCK FEEDBACK
ALARM WARNING TYPE
REMOTE UNLOCK FEEDBACK
HEADLAMPS ON AT EXIT
PERIMETER LIGHTING
SEAT POSITION RECALL
EASY EXIT DRIVER SEAT
CURB VIEW ASSIST
DISPLAY LANGUAGE
DISPLAY UNITS (ENG/MET)
3-57