2002 CHEVROLET TRAIL BLAZER check engine light

2-17
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 light 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.
When the alarm is set the power door unlock switch is
not operational.
If the alarm does not sound when it should but the
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 headlamps do not
flash, the vehicle should be serviced by your dealer.
Passlock

Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel 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, the fuel system is disabled
and the vehicle will not start.
During normal operation, the SECURITY light will
turn off approximately five seconds after the key is
turned to RUN.
If the engine stalls and the SECURITY light flashes,
wait about 10 minutes until the light stops flashing
before trying to restart the engine. Remember to release
the key from START as soon as the engine starts.

2-18
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the SECURITY light 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.New Vehicle ªBreak-Inº
NOTICE:
Your vehicle doesn't need an elaborate
ªbreak
-in.º But it will perform better in the long
run if you follow these guidelines:

Keep your speed at 55 mph (88 km/h) or
less for the first 500 miles (805 km).

Don't drive at any one speed
-- fast or
slow
-- for the first 500 miles (805 km).
Don't make full
-throttle starts.

Avoid making hard stops for the first
200 miles (322 km) or so. During this time
your new brake linings aren't yet broken
in. Hard stops with new linings can mean
premature wear and earlier replacement.
Follow this breaking
-in guideline every
time you get new brake linings.

Don't tow a trailer during break
-in.
See ªTowing a Trailerº in the Index for
more information.

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Volume Control: You can control the volume of the
OnStar System using either the volume control knob
on the radio or using the steering wheel volume control
(if equipped).
Telltale Light: This light will indicate the status of
the system. A solid green light will come on when you
start the vehicle to let you know that the system is on
and is ready to make or receive calls.
If the light blinks green it means that an incoming or
outgoing call is in progress. Press the Call
ANSWER/END button if you notice the light blinking
and you are not on a call.
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
automatically sent 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.

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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.
Your vehicle may also have a Driver Information Center
(DIC) that works along with the warning lights and
gages. See ªDriver Information Center (DIC) in
the Index.
Safety Belt Reminder Light
When the key is turned to RUN, a chime 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 chime
nor the light will come on.

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Charging System Indicator Light
The charging system light
will come on briefly when
you turn on the ignition,
but the engine is not
running, as a check to show
you it is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have
a problem with the charging system. It could indicate
that you have problems with a generator drive belt, or
another electrical problem. Have it checked right away.
Driving while this light is on could drain your battery.
If you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the radio
and air conditioner.
Voltmeter Gage
When your engine is not
running, but the ignition
is on (in RUN), this gage
shows your battery's state
of charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between
the low and high warning zones indicate the normal
operating range.

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Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, it means that your
engine coolant has overheated. If you have been
operating your vehicle under normal driving conditions,
you should pull off the road, stop your vehicle and turn
off the engine as soon as possible.
See ªEngine Overheatingº in the Index for
more information.
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.

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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.

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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.