check engine CHEVROLET TRAIL BLAZER 2003 1.G Owner's Guide

Engine Oil
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick
handle is a yellow ring
located in the engine
compartment toward the
passenger's side of
the vehicle. See
Engine
Compartment Overview on
page 5-12
for more
information on location.Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
L6 Engine
V8 Engine
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As in the chart shown previously, SAE 5W-30 is the
only viscosity grade recommended for your vehicle. You
should look for and use only oils which have the API
Starburst symbol and which are also identi®ed as
SAE 5W-30. If you cannot ®nd such SAE 5W-30 oils,
you can use an SAE 10W-30 oil which has the API
Starburst symbol, if it's going to be 0ÉF (-18ÉC)
or above. Do not use other viscosity grade oils, such as
SAE 10W-40 or SAE 20W-50 under any conditions.
Notice:Use only engine oil with the American
Petroleum Institute Certi®ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
žoil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below-20ÉF (-29ÉC), it is
recommended that you use either an
SAE 5W-30 synthetic oil or an SAE 0W-30 oil.
Both will provide easier cold starting and better
protection for your engine at extremely low
temperatures.
Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil
(GM Oil Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil and ®lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENG OIL light will come on.
Change your oil as soon as possible within the
next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil
life system may not indicate that an oil change is
necessary for over a year. However, your engine oil and
®lter must be changed at least once a year and at
this time the system must be reset. It is also important
to check your oil regularly and keep it at the proper
level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
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Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission ¯uid
level is when the engine oil is changed.
Change both the ¯uid and ®lter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:
·In heavy city traffic where the outside temperature
regularly reaches 90ÉF (32ÉC) or higher.
·In hilly or mountainous terrain.
·When doing frequent trailer towing.
·Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter every
100,000 miles (166 000 km).
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little ¯uid can damage
your transmission. Too much can mean that some
of the ¯uid could come out and fall on hot engine
part or exhaust system parts, starting a ®re.
Too little ¯uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission ¯uid.
Wait at least 30 minutes before checking the
transmission ¯uid level if you have been driving:
·When outside temperatures are above 90ÉF (32ÉC).
·At high speed for quite a while.
·In heavy traffic-especially in hot weather.
·While pulling a trailer.
To get the right reading, the ¯uid should be at normal
operating temperature, which is 180ÉF to 200ÉF
(82ÉC to 93ÉC).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50ÉF
(10ÉC). If it's colder than 50ÉF (10ÉC), drive the vehicle
in THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes.
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A cold ¯uid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for ®ve minutes if outside temperatures are
50ÉF (10ÉC) or more. If it's colder than 50ÉF (10ÉC), you
may have to idle the engine longer. Should the ¯uid
level be low during this cold check, you
mustcheck the
¯uid hot before adding ¯uid. Checking the ¯uid hot
will give you a more accurate reading of the ¯uid level.
Checking the Fluid Level
Prepare your vehicle as follows:
·Park your vehicle on a level place. Keep the engine
running.
·With the parking brake applied, place the shift lever
in PARK (P).
·With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
·Let the engine run at idle for three minutes or more.Then, without shutting off the engine, follow these steps:
The automatic
transmission dipstick
handle with the
transmission and lock
symbol is located in the
engine compartment
on the passenger's side of
the vehicle.
See
Engine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again. Check both sides of the
dipstick, and read the lower level.
3. If the ¯uid level is in the acceptable range, push the
dipstick back in all the way; then ¯ip the handle
down to lock the dipstick in place.
5-23

How to Add Fluid
Refer to the Maintenance Schedule to determine
what kind of transmission ¯uid to use. See
Part D: Recommended Fluids and Lubricants on
page 6-18.
Add ¯uid only after checking the transmission ¯uid while
it is hot. (A cold check is used only as a reference.) If
the ¯uid level is low, add only enough of the proper
¯uid to bring the level up to the HOT area for a
hot check. It doesn't take much ¯uid, generally less
than one pint (0.5 L).
Don't over®ll.
Notice:
We recommend you use only ¯uid labeled
DEXRONž-III, because ¯uid with that label is
made especially for your automatic transmission.
Damage caused by ¯uid other than DEXRON
ž-III is
not covered by your new vehicle warranty.
·After adding ¯uid, recheck the ¯uid level as
described under ªHow to Check².
·When the correct ¯uid level is obtained, push the
dipstick back in all the way; then ¯ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOLžmay
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs ®rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
ž(silicate-free) coolant in your vehicle.
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What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOLžcoolant. If you use this coolant
mixture, you don't need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle's coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch ®re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
žcoolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you don't
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Checking Coolant
The engine coolant
recovery tank is in the
engine compartment
on the passenger's side of
the vehicle. See
Engine
Compartment Overview on
page 5-12
for more
information on location.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at FULL
COLD, or a little higher.
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Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the coolant recovery tank.
{CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. With the coolant recovery tank, you will
almost never have to add coolant at the
radiator. Never turn the radiator pressure
cap Ð even a little Ð when the engine and
radiator are hot.
Add coolant mixture at the recovery tank, but be careful
not to spill it.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
Occasionally check the coolant level in the radiator. For
information on how to add coolant to the radiator,
see
Cooling System on page 5-29.
Radiator Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
See
Engine Compartment Overview on page 5-12for
information on location.
5-26

Power Steering Fluid
The power steering ¯uid
reservoir is located in the
engine compartment. It
is on the passenger's
side of vehicles with the
L6 engine and is on
the driver's side of vehicles
with the V8 engine. See
Engine Compartment
Overview on page 5-12for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering ¯uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A ¯uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then
remove the cap again and look at the ¯uid level on the
dipstick.
For vehicles with the L6 engine, the level should be at
the C (cold) mark. For vehicles with the V8 engine,
the level should be at the FULL mark. If necessary, add
only enough ¯uid to bring the level up to the mark.
What to Use
To determine what kind of ¯uid to use, seePart D: Recommended Fluids and Lubricants on
page 6-18. Always use the proper ¯uid. Failure to use
the proper ¯uid can cause leaks and damage hoses
and seals.
5-36

Brakes
Brake Fluid
Your brake master cylinder reservoir is ®lled with DOT-3
brake ¯uid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brake ¯uid level in
the reservoir might go down. The ®rst is that the
brake ¯uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the ¯uid level goes back up. The other reason isthat ¯uid is leaking out of the brake system. If it is, you
should have your brake system ®xed, since a leak
means that sooner or later your brakes will not work
well, or will not work at all.
So, it is not a good idea to ªtop offº your brake ¯uid.
Adding brake ¯uid will not correct a leak. If you add ¯uid
when your linings are worn, then you will have too
much ¯uid when you get new brake linings. You should
add (or remove) brake ¯uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake ¯uid, it can spill on
the engine. The ¯uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
¯uid only when work is done on the brake
hydraulic system. See ªChecking Brake Fluidº
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake ¯uid. See
Part C: Periodic
MaintenanceInspections on page 6-16.
5-38

Checking Brake Fluid
You can check the brake ¯uid without taking off the cap.
Just look at the brake ¯uid
reservoir. The ¯uid level
should be above MIN. If it
is not, have your brake
system checked to
see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
What to Add
When you do need brake ¯uid, use only DOT-3 brake
¯uid. Use new brake ¯uid from a sealed container
only. See
Part D: Recommended Fluids and Lubricants
on page 6-18.Always clean the brake ¯uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of ¯uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper brake
¯uid.
Notice:
·Using the wrong ¯uid 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 will have to be
replaced. Do not let someone put in the wrong
kind of ¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
Appearance
Care on page 5-79.
5-39