1998 CHEVROLET EXPRESS check engine

Downloaded from www.Manualslib.com manuals search engine Electronic Road-Speed Governor (Gasoline Engines) (Option)
This optional system automatically controls vehicle top
speed. The system controller receives a signal from the
vehicle speed sensor and reduces power when the
vehicle speed reaches
the maximum 65 mph (105 kdh)
governed speed.
Warning Lights, Gages
and Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause an
expensive repair or replacement. Paying attention to
your warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be
or is a
problem with one of your vehicle’s functions. As you
will see in the details on
the next few pages, some
warning lights come on briefly when
you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens. Gages
can indicate when there may be or is a problem
with one
of your vehicle’s functions. Often gages and
warning lights work together
to let you know when
there’s a problem with your vehicle.
When one of
the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly
-- and even
dangerous.
So please get to know your warning lights
and gages. They’re a big help.
Safety Belt Reminder Light
When the key is turned to RUN or START, a tone will
come on for about eight seconds to remind people to
fasten their safety belts, unless the driver’s safety belt is
already buckled.
The safety belt light will
also come on and stay on
for about
20 seconds, then it
will flash for about
55 seconds.
If the driver’s belt is already buckled, neither the tone
nor the light will come on.

Downloaded from www.Manualslib.com manuals search engine Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows AIR BAG. The system checks the
air bag’s electrical system for malfunctions. The light
tells you if there is an electrical problem. The system
check includes the air bag sensor, the air bag modules,
the wiring and the crash sensing and diagnostic module.
For more information on the air bag system, see “Air
Bag” in the Index.
AIR
BAG
This light will come on
when you start your engine,
and it will flash for a few
seconds. Then the light
should
go out. This means
the system is ready.
If
the air bag readiness light stays on after you start the
engine or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away. The
air bag readiness light should flash for
a few
seconds
when you turn the ignition key to RUN. If the
light doesn’t come on then, have it fixed
so it will be
ready to warn you if there is a problem.
Charging System Light
This light should come on
briefly
when you turn on the
ignition, before starting the
engine,
as a check to show
you it is working.
After the engine starts, the light should
go out. If it stays
on or comes on while you are driving, you may have a
problem with your charging system. It could indicate a
problem with the alternator drive belt, or some other
charging system problem. Have it checked right away.
Driving while this light is on could drain your battery.
If you must drive a short distance with this light
on, it
helps to turn off all your accessories, such as the radio
and air conditioner.
2-54

Downloaded from www.Manualslib.com manuals search engine Malfunction Indicator Lamp (Service Engine Soon Light) (Gasoline Engine)
81 Your vehicle is equipped
SERVICE
ENGINE
I
SOON
with a computer which
monitors operation
of the
fuel, ignition and emission
control systems.
This system is called OBD I1 (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 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.
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:
0
0
Light Flashing -- A misfire condition has been
detected.
A misfire increases vehicle emissions and
may damage the emission control system
on your
vehicle.
GM or qualified service center diagnosis
and service may be required.
Light On Steady -- An emission control system
malfunction has been detected on your vehicle.
GM
or qualified service center diagnosis and service may
be required.
2-58

Downloaded from www.Manualslib.com manuals search engine Have you recently changed brands of fuel?
If
so, be sure to fuel your vehicle with quality fuel (see
“Fuel” 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.
Oil Pressure Gage
The oil pressure gage
pressure in psi (pounds per
square inch) when the
shows the engine oil
8o I
engine is running. Canadian
vehicles indicate pressure in kPa (kilopascals).
OIL Wh
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.
2-60

Downloaded from www.Manualslib.com manuals search engine I A 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.
I NOTICE:
Damage to your engine from neglected oil
problems can be costly and
is not covered by
your warranty.
Security Light
SECURITY
This light will come on
briefly when you turn the
ignition key to START.
m
The light will stay on until the engine starts. If the
flashes, the Passlock%ystem has entered
a tampel light I-
mode. If the vehicle
fails to start, see “Passlock” in
the Index.
If the light comes
on continuously while driving and
stays on, there may be a problem with the Passlock
System.
Your vehicle will not be protected by Passlock,
and you should see your
GM dealer.
2-61

Downloaded from www.Manualslib.com manuals search engine Daytime Running Lamps Indicator Light
You may have this light on
the instrument panel. It will
light whenever the
DRL are
on. It is also a reminder to
turn on your headlamps
when driving at night.
Check Gages Light
CHECK
GAGES
The CHECK GAGES light
will come on briefly when
you are starting the engine.
If
the light comes on and stays on while you are driving,
check your coolant temperature and engine oil pressure
gages
to see if they are in the warning zones.
2-62

Downloaded from www.Manualslib.com manuals search engine Tips About Your Audio System
Hearing damage from loud noise is almost undetectable
until
it is too late. Your hearing can adapt to higher
volumes of sound. Sound that seems normal can be loud
and harmful
to your hearing. Take precautions by
adjusting the volume control on your radio to a safe
sound level before your hearing adapts
to it.
To help avoid hearing loss or damage:
Adjust the volume control to the lowest setting.
0 Increase volume slowly until you hear comfortably
and clearly.
I
NOTICE:
Before you add any sound equipment to your
vehicle
-- like a tape player, CB radio, mobile
telephone or two-way radio
-- be sure you can
add what you want.
If you can, it’s very
important to do it properly. Added sound
equipment may interfere with the operation
of
your vehicle’s engine, Delco Electronics radio or
other systems, and even damage them. Your
vehicle’s systems may interfere with the
operation
of sound equipment that has been
added improperly.
So, before adding sound equipment, check with
your dealer and be sure to check Federal rules
covering mobile radio and telephone units.
3-24

Downloaded from www.Manualslib.com manuals search engine Anti-Lock Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent
a braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself.
You may
hear a momentary motor
or clicking noise while this test
is going
on. This is normal.
ANTI -
LOCK
United States Canada
If there’s a problem with the anti-lock brake system, this
warning light will stay
on. See “Anti-Lock Brake
System Warning Light” in the Index. Here’s how anti-lock works. Let’s say the road
is wet.
You’re driving safely. Suddenly an animal jumps out
in
front of you.
You slam on the brakes. Here’s what happens with ABS.
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at
both rear wheels.