service CHEVROLET EXPRESS 2002 User Guide

2-61 Malfunction Indicator Lamp (Service
Engine Soon Light in the United States
or Check Engine Light in Canada)
(4.3L, 5.0L & 5.7L Engines and
8.1L California Gasoline Engine)
United States Canada
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 SERVICE ENGINE SOON or
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.

2-62
NOTICE:
Modifications 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 the SERVICE ENGINE SOON or
CHECK ENGINE light to come on.
Modifications 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 Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.

2-63
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 ªIf the Light Is On Steadyº 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 ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.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. See ªFilling Your Tankº in the Index.
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.

2-64
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
See ªFuelº in the Index. 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,
have your dealer or qualified service center 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 in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
SERVICE ENGINE SOON or 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, see your dealer or qualified service center
to prepare the vehicle for inspection.

2-65 Malfunction Indicator Lamp (Service
Engine Soon Light) (Check Engine Light)
(8.1L Gasoline Engine -- Except California)
United States Canada
If this light comes on or flashes while you are driving,
two things may happen.
First, you won't notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may stall
without warning. If either of these things happen, drive
or tow your vehicle to your dealer for service.This light should come on when the ignition is on, but
the engine is not running, as a check to show you it is
working. If it does not come on at all, have it repaired.
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.
Reduced Engine Power
The REDUCED ENGINE
POWER light will come
on when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
See ªEngine Overheatingº in the Index for
further information.

2-66 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.
A reading in the low pressure zone may be caused by a
dangerously low oil level or other problem causing low
oil pressure. Check your oil as soon as possible.CAUTION:
Don't keep driving if the oil pressure is low.
If you do, your engine can become so hot that it
catches fire. 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.

3-14
To adjust balance or fade to the middle position, select
BAL or FAD. Then press and hold AUDIO for more
than two seconds until you hear a beep. L and a zero or
F and a zero will appear on the display. To adjust both
tone controls and both speaker controls to the middle
position, end out of audio mode by pressing the AUDIO
button until the display goes blank. Then press and hold
AUDIO for more than two seconds until you hear a
beep. CEN will appear on the display.
Radio Messages
CAL (Calibrated): Your audio system has been
calibrated for your vehicle from the factory. If CAL
appears on the display it means that your radio has not
been configured properly for your vehicle and must be
returned to the dealership for service.
LOC (Locked): This message is displayed when the
Theftlock

system has locked up. Your vehicle must
be returned to the dealership for service.
AM FM Stereo with Cassette Tape Player
(If Equipped)
Playing the Radio
PWR (Power): Press this knob to turn the system on
and off.
VOL (Volume): Turn this knob clockwise to increase
volume. Turn it counterclockwise to decrease volume.
RCL (Recall): Pressing this knob will display the
station being played or it will display the clock. Clock
display is available with the ignition turned off.

3-17
To adjust balance or fade to the middle position, select
BAL or FAD. Then press and hold AUDIO for more
than two seconds until you hear a beep. L and a zero or
F and a zero will appear on the display. To adjust both
tone controls and both speaker controls to the middle
position, end out of audio mode by pressing the AUDIO
button until the display goes blank. Then press and hold
AUDIO for more than two seconds until you hear a
beep. CEN will appear on the display.
Radio Messages
CAL (Calibration): Your audio system has been
calibrated for your vehicle from the factory. If CAL
appears on the display it means that your radio has not
been configured properly for your vehicle and must be
returned to the dealership for service.
LOC (Locked): This message is displayed when the
Theftlock

system has locked up. Your vehicle must be
returned to the dealership for service.Playing a Cassette Tape
Your tape player is built to work best with tapes that are
up to 30 to 45 minutes long on each side. Tapes longer
than that are so thin they may not work well in this
player. The longer side with the tape visible should face
to the right. If the ignition is on, but the radio is off, the
tape can be inserted and will begin playing. If you hear
nothing but a garbled sound, the tape may not be in
squarely. Press the eject button to remove the tape and
start over.
While the tape is playing, use the VOL, AUDIO and
SEEK controls just as you do for the radio. The radio
will display UP if the top side of the tape is playing.
DN (Down) will appear if the bottom side is playing.
If you want to insert a tape when the ignition is off,
first press the eject button or the RCL knob.
If an error appears on the display, see ªCassette Tape
Messagesº later in this section.

3-22
Adjusting the Speakers (Balance/Fade)
AUDIO: To adjust the balance between the right and
left speakers, press and release AUDIO until BAL
appears on the display. Then press and hold the up arrow
to move the sound to the right speakers or the down
arrow to move the sound to the left speakers. R and a
number will appear on the display when the sound is
balanced toward the right speakers. L and a number
will appear on the display when the sound is balanced
toward the left speakers. L and a zero will appear on
the display when the sound is balanced between the
speakers. Release the up or down arrow when you find
the speaker balance you want or when the maximum or
minimum level is reached.
To adjust the fade between the front and rear speakers,
press and release AUDIO until FAD appears on the
display. Then press and hold the up arrow to move the
sound to the front speakers or the down arrow to move
the sound to the rear speakers. F and a number will
appear on the display when the sound is balanced
toward the front speakers. R and a number will appear
on the display when the sound is balanced toward the
rear speakers. F and a zero will appear on the display
when the sound is balanced between the speakers.
Release the up or down arrow when you find the speaker
balance you want or when the maximum or minimum
level is reached.To adjust balance or fade to the middle position, select
BAL or FAD. Then press and hold AUDIO for more
than two seconds until you hear a beep. L and a zero or
F and a zero will appear on the display. To adjust both
tone controls and both speaker controls to the middle
position, end out of audio mode by pressing the AUDIO
button until the display goes blank. Then press and hold
AUDIO for more than two seconds until you hear a
beep. CEN will appear on the display.
Radio Messages
CAL (Calibrated): Your audio system has been
calibrated for your vehicle from the factory. If CAL
appears on the display it means that your radio has not
been configured properly for your vehicle and must be
returned to the dealership for service.
LOC (Locked): This message is displayed when the
Theftlock

system has locked up. Your vehicle must be
returned to the dealership for service.
Playing a Compact Disc
Insert a disc partway into the slot, label side up. The player
will pull it in. The disc should begin playing. The display
will show CD. If you want to insert a compact disc with
the ignition off, first press RCL or the eject button.
If an error appears on the display, see ªCompact Disc
Messagesº later in this section.

3-30
INFO (Information): If the current station has a
message, the information icon will appear on the
display. These text messages are from the RDS
broadcaster to the listening public and may be general
information such as artist and song title, call in phone
numbers, etc. Press this button to see the message.
If the whole message does not appear on the display,
parts of the message will appear every three seconds
until the message is completed. To scroll through the
message at your own speed, press the INFO button
again for less than one second. A new group of words
will appear on the display. Once the complete message
has been displayed, the information icon will disappear
from the display until another new message is received.
The old message can be displayed by pressing the
INFO button until a new message is received or a
different station is tuned to.
TRAF (Traffic): Press this button to receive traffic
announcements. If the current station does not broadcast
traffic announcements, the radio will seek to a station
that does. The traffic symbol will flash on the display.
When the radio finds a station that broadcasts traffic
announcements, it will stop. If no station is found,
NO TRAF will appear on the display.Your radio can be programmed to interrupt the playback
of a cassette tape, CD or FM radio by enabling the
traffic interrupt feature. Press the TRAF button once to
seek to an RDS station that supports the traffic interrupt
feature if the current station does not. The traffic symbol
will flash on the display when seeking for a station that
supports traffic interrupt. When the traffic interrupt
feature is on, TRAF will appear on the display.
When a traffic announcement comes on the current radio
station, you will hear it, even if the volume is muted or a
cassette tape or compact disc is playing. The traffic
symbol and TRAFFIC will appear on the display while
the traffic announcement plays. If the cassette tape or
compact disc player was being used, the tape or compact
disc will stay in the player and resume play at the point
where it stopped.
Radio Messages
CAL ERR (Calibration Error): This message is
displayed when the radio has not been calibrated
properly for the vehicle. You must return to the
dealership for service.
LOCKED: This message is displayed when the
THEFTLOCK

system has locked up. You must
return to the dealership for service.