service indicator CHEVROLET TRAIL BLAZER 2002 1.G Owners Manual

2-27
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged in
two
-wheel drive. It also provides the best fuel economy.
A4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
A4WD, the front axle is engaged, but the vehicle's
power is sent to the rear wheels. When the vehicle
senses a loss of traction, the system will automatically
engage four
-wheel drive. Driving in this mode results in
slightly lower fuel economy than 2HI.
4HI: Use 4HI when you need extra traction, such as
on snowy or icy roads or in most off
-road situations.
This setting also engages your front axle to help drive
your vehicle.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
and climbing or descending steep hills.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). You or someone else could be
seriously injured. Be sure to set the parking
brake before placing the transfer case in
NEUTRAL. See ªParking Brakeº in the Index.
NEUTRAL: Shift the vehicle's transfer case to
NEUTRAL only when towing your vehicle. See
ªRecreational Vehicle Towingº or ªTowing Your
Vehicleº in the Index for more information.
An indicator light in the knob will show you which
position the transfer case is in. The indicator lights will
come on briefly when you turn on the ignition and one
will stay on. If the lights do not come on, you should
take your vehicle to your dealer for service. An indicator
light will flash while shifting the transfer case. It will
remain illuminated when the shift is complete. If for
some reason the transfer case cannot make a requested
shift, it will return to the last chosen setting.

2-28
If the SERVICE 4WD light on the instrument panel
cluster stays on, you should take your vehicle to your
dealer for service. See ªService 4WDº in the Index for
further information.
Shifting to 4HI or A4WD
Turn the knob to 4HI or A4WD. This can be done at any
speed and the indicator light will flash while shifting. It
will remain illuminated when the shift is complete.
Shifting to 2HI
Turn the knob to 2HI. This can be done at any speed.
Shifting to 4LO
To shift to 4LO, the vehicle's engine must be running
and the vehicle must be stopped or moving less than
2 mph (3.2 km/h) with the transmission in
NEUTRAL (N). The preferred method for shifting into
4LO is to have your vehicle moving 1 or 2 mph
(1.6 to 3.2 km/h). Turn the knob to 4LO. You must wait
for the 4LO indicator light to stop flashing and remain
illuminated before shifting your transmission into gear.If you knob to 4LO when your vehicle is in gear
and/or moving, the 4LO indicator light will flash for
30 seconds and not complete the shift unless your
vehicle is moving less than 2 mph (3.2 km/h) and the
transmission is in NEUTRAL (N). After 30 seconds, the
transfer case will return to the setting last chosen.
Shifting Out of 4LO
To shift from 4LO to 4HI, A4WD or 2HI your vehicle
must be stopped or moving less than 2 mph (3.2 km/h)
with the transmission in NEUTRAL (N) and the engine
running. The preferred method for shifting out
of 4LO is to have your vehicle moving 1 or 2 mph
(1.6 to 3.2 km/h). Turn the knob to 4HI, A4WD or 2HI.
You must wait for the 4HI, A4WD or 2HI indicator light
to stop flashing and remain illuminated before shifting
your transmission into gear.
If the 4HI, A4WD or 2HI knob is turned when your
vehicle is in gear and/or moving, the 4HI, A4WD
or 2HI indicator light will flash for 30 seconds but
will not complete the shift unless your vehicle is
moving less than 2 mph (3.2 km/h) with the
transmission in NEUTRAL (N).

2-79
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.

3-23
Radio/Cassette Tape Messages
(CAL ERR): 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.
(CHK TAPE): If CHK TAPE appears on the radio
display, the tape won't play because of one of the
following errors.

The tape is tight and the player can't turn the tape
hubs. Remove the tape. Hold the tape with the open
end down and try to turn the right hub
counterclockwise with a pencil. Turn the tape over
and repeat. If the hubs do not turn easily, your tape
may be damaged and should not be used in the
player. Try a new tape to make sure your player is
working properly.

The tape is broken. Try a new tape.

The tape is wrapped around the tape head. Attempt
to get the cassette out. Try a new tape.(CLEAN): If this message appears on the display, the
cassette tape player needs to be cleaned. It will still play
tapes, but you should clean it as soon as possible to
prevent damage to the tapes and player. See ªCare of
Your Cassette Tape Playerº in the Index. After you clean
the player, press and hold the EJT button for five
seconds to reset the CLEAN indicator. The radio will
display CLEANED to show the indicator was reset.
If any error occurs repeatedly or if an error can't be
corrected, please contact your dealer.

3-59
If your vehicle is equipped with the AM-FM Stereo with
Cassette Tape and Compact Disc Player with Radio Data
System (RDS) and Automatic Tone Control:
1. Turn the ignition to RUN or ACCESSORY.
2. Turn the radio off.
3. Press and hold the TAPE CD button for five seconds.
READY will appear on the display and a cassette
icon will flash for five seconds.
4. Insert the scrubbing action cleaning cassette.
5. Eject the cleaning cassette after the manufacturer's
recommended cleaning time.
When the cleaning cassette has been ejected, the broken
tape detection feature is active again.You may also choose a non-scrubbing action, wet-type
cleaner which uses a cassette with a fabric belt to clean
the tape head. This type of cleaning cassette will not
eject on its own. A non
-scrubbing action cleaner may
not clean as thoroughly as the scrubbing type cleaner.
The use of a non
-scrubbing action, dry-type cleaning
cassette is not recommended.
After you clean the player, press and hold the cassette
eject symbol or EJT button for five seconds to reset the
CLEAN indicator. The radio will display CLEANED to
show the indicator was reset.
Cassettes are subject to wear and the sound quality
may degrade over time. Always make sure the cassette
tape is in good condition before you have your tape
player serviced.

6-5 Additives
Some gasolines that are not reformulated for low
emissions may contain an octane
-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs
and the performance of the emission control system
may be affected. The malfunction indicator lamp may
turn on. If this occurs, return to your authorized
GM dealer for service.
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work properly.
You should not have to add anything to your fuel.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available
in your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly
if they comply with the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don't use fuel containing
methanol. It can corrode metal parts in your
fuel system and also damage plastic and rubber
parts. That damage wouldn't be covered under
your warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to find. Never use leaded gasoline or any other fuel not
recommended in the previous text on fuel. Costly repairs
caused by use of improper fuel wouldn't be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major oil company that does business in
the country where you'll be driving.

6-16
Engine Air Cleaner/Filter
The engine air cleaner/filter
is located toward the front
of the engine compartment
on the passenger's side of
the vehicle.
See ªEngine Compartment Overviewº in the Index for
more information on engine air cleaner/filter location.
The engine air cleaner/filter
assembly has an indicator
that lets you know when the
air filter is dirty and needs
to be serviced. The indicator
is located on the engine
air cleaner/filter air duct.
See ªEngine Compartment Overviewº in the Index
for more information on engine air cleaner/filter
indicator location.
The service window (A) with the percentage scale
shows the amount of engine air cleaner/filter life used.
When both service window (A) and service window (B)
turn orange, replace the engine air cleaner/filter.

6-17
After changing the engine air cleaner/filter, press the
button on top of the indicator to reset it.
See ªOwner Checks and Servicesº in the Index to
determine when to check the indicator.
To replace the engine air cleaner/filter, do the following:
1. Remove the three screws on the engine air
cleaner/filter and lift off the cover.
2. Twist out the old engine air cleaner/filter and replace
it with a new one.
3. Reinstall the cover.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.

6-32
NOTICE:

Using the wrong fluid can badly damage
brake system parts. For example, just a few
drops of mineral
-based oil, such as engine
oil, in your brake system can damage brake
system parts so badly that they'll have to be
replaced. Don't let someone put in the
wrong kind of fluid.

If you spill brake fluid on your vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle. If you do, wash it off
immediately. See ªAppearance Careº
in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built
-in wear indicators that make
a high
-pitched warning sound when the brake pads are
worn and new pads are needed. The sound may come
and go or be heard all the time your vehicle is moving
(except when you are pushing on the brake pedal firmly).
CAUTION:
The brake wear warning sound means that soon
your brakes won't work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
NOTICE:
Continuing to drive with worn-out brake pads
could result in costly brake repair.

Scheduled Maintenance
7-6Engine Oil Scheduled Maintenance
Change engine oil and filter as indicated by the GM
Oil Life System
(or every 12 months, whichever
occurs first). Reset the system. The system will show
you when to change the oil
-- usually between
3,000 miles (5 000 km) and 12,000 miles (20 000 km)
since your last oil change. Under severe conditions, the
indicator may come on before 3,000 miles (5 000 km).
Never drive your vehicle more than 12,000 miles
(20 000 km) or 12 months without an oil and
filter change.The system won't detect dust in the oil. So if you drive
in a dusty area, be sure to change your oil and filter
every 3,000 miles (5 000 km) or sooner if the CHANGE
ENG OIL light appears. Remember to reset the Oil Life
System when the oil and filter have been changed.
See ªOil Life Systemº in the Index for information
on resetting.
An Emission Control Service.