check engine light CHEVROLET AVALANCHE 2002 1.G Owners Manual

2-26
Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver's window
and open the driver's door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open,
or with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for
the SECURITY message to go out.
4. Then reach in through the window, unlock the
door with the manual door lock and open the door.
This should set off the alarm.
If the alarm does not sound when it should but the
vehicle's headlamps flash, check to see if the horn
works. The horn fuse may be blown. To replace the
fuse, see ªFuses and Circuit Breakersº in the Index.
If the alarm does not sound or the vehicle's headlamps
do not flash, the vehicle should be serviced by an
authorized service center.
Passlock

Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel to the engine if the ignition lock cylinder is
turned with a valid key. If a correct key is not used or the
ignition lock cylinder is tampered with, fuel is disabled.
If the engine stalls and the SECURITY message flashes,
wait until the light stops flashing before trying to restart
the engine. Remember to release the key from START
as soon as the engine starts.
If the engine is running and the SECURITY message
comes on, you will be able to restart the engine if you
turn the engine off. However, your Passlock system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock at this
time. You may also want to check the fuse (see ªFuses
and Circuit Breakersº in the Index). See your dealer
for service.
In an emergency, call the GM Roadside Assistance
Center. See ªRoadside Assistanceº in the Index.

2-92
The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar button to
attempt to contact an advisor. If the connection is made,
the advisor will assist you with steps to take to make
sure that the system is functioning properly. If you
cannot contact the advisor, take your vehicle to your
dealership as soon as possible for assistance.
Safety and Security Services
Automatic Notification of Air Bag Deployment: If an
air bag deploys, a priority emergency signal is sent
automatically to the center. An advisor will locate your
vehicle's position, try to contact you and assist you in
the situation. If the center is unable to contact you,
an emergency service provider will be contacted.
Stolen Vehicle Tracking: Call the center at
1
-888-4-ONSTAR (1-888-466-7827) to report
your vehicle stolen. The system can then locate and
track your vehicle and the advisor will be able to notify
the proper authorities.
Roadside Assistance with Location: For vehicle
breakdowns, press the OnStar button. An advisor will
contact the appropriate help.Remote Diagnostics: If an instrument panel light
comes on, the center can perform a check of the engine
on
-board computer. An advisor can then recommend
what action needs to be taken.
OnStar MED
-NET: Med-Net can store your personal
medical history and provide it to emergency personnel
if necessary. (Requires activation and an additional fee.)
Accident Assist: An advisor can provide step
-by-step
guidance following an accident.
Remote Door Unlock: To contact the center, call
1
-888-4-ONSTAR. You will be required to provide
your security information. An advisor will send a
command to your vehicle to unlock itself. The advisor
can delay unlocking your vehicle. Remote Door Unlock
is disabled 48 hours after the vehicle is parked to
maintain the battery charge.
Vehicle Locator Service: To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will send
a command to your vehicle to sound the horn and/or
flash the lamps.
In order to provide you with excellent service, calls with
the OnStar Center may be monitored or recorded.

2-101
Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has been
driven, in either miles (used in the United States) or
kilometers (used in Canada).
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
Press the reset button to toggle between the trip
odometer and the regular odometer. Holding the reset
button for two seconds while the trip odometer is
displayed will reset it.
To display the odometer reading with the ignition off,
press the reset button.
Engine Hour Meter Display
The odometer can also display the number of hours
the engine has run. To display the hour meter, turn the
ignition off, press and hold the reset button for at least
four seconds. The hour meter will be displayed for
up to 30 seconds, or until the ignition is turned on.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).
Warning Lights, Gages and Indicators
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.

2-110
Malfunction Indicator Lamp
(Service Engine Soon Light in the United
States or Check Engine Light in Canada)
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.
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.

2-111
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.
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.

2-112
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.

2-116
Message Center
The message center is located on the left side of the
instrument panel cluster. It gives you important safety
and maintenance facts. When you turn the ignition on,
the entire center lights up for just a few seconds.
As needed, the message center will display one of
the following messages. The message center is capable
of alternating among different messages if needed.
Battery
If this message is displayed
when the engine is running,
you may have a problem
with your charging system.The battery display will also stay on while the key is in
RUN until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this message displayed could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories,
such as the radio and the air conditioner.

2-120
Reduced Engine Power
This message is displayed
when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
If your vehicle is equipped with the 8.1L engine, this
light may come on because of an electronic throttle
control system fault. See ªEngine Overheatingº in the
Index for further information.
Check Eng Oil Pressure
This message is displayed
when the engine oil pressure
is low.
See ªOil Pressure Gageº in the Index for more information.
Check Eng Oil Level
This message is displayed
when the engine oil level
is low.
Once oil is added, it may need time to drain and settle
in the engine before this message will turn off. It is best
to let the engine cool down (if it is hot) or warm up
(if it is cold) and cycle the ignition to be sure this
message turns off. Refer to the dipstick for the
correct level.
See ªEngine Oilº in the Index on how to check the
oil level and for what type of oil to add.

4-7
Avoid needless heavy braking. Some people drive
in spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic.
This is a mistake. Your brakes may not have time to
cool between hard stops. Your brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic following
distances, you will eliminate a lot of unnecessary
braking. That means better braking and longer
brake life.
If your engine ever stops while you're driving, brake
normally but don't pump your brakes. If you do, the
pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and the
brake pedal will be harder to push.
Anti-Lock Brake System (ABS)
Your vehicle has anti-lock brakes. 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.
If there's a problem with
the anti
-lock brake system,
this warning light will stay
on. See ªAnti
-Lock Brake
System Warning Lightº in
the Index.

5-5
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight
if you need more light.
Be sure the batteries have enough water. Be sure
the battery has enough water. You don't need to
add water to the ACDelco

battery (or batteries)
installed in every new GM vehicle. But if a
battery has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take
care of that first. If you don't, explosive gas
could be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.
5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some basic
things you should know. Positive (+) will go to
positive (+) or a remote positive (+) terminal if the
vehicle has one. Negative (
-) will go to a heavy,
unpainted metal engine part or a remote negative (
-)
terminal, if the vehicle has one.
Don't connect positive (+) to negative (
-) or you'll
get a short that would damage the battery and maybe
other parts too.