2003 TOYOTA COROLLA cooling

’03 Corolla U (L/O 0201)
832003 MY COROLLA_U (OM12744U)
The gauge indicates the engine coolant
temperature when the ignition switch is
on. The engine operating temperature
will vary with changes in weather and
engine load.
If the needle moves into the red zone,
your engine is too hot. If your vehicle
overheats, stop your vehicle and allow the
engine to cool.
Your vehicle may overheat during severe
operating conditions, such as:
Driving up a long hill on a hot day.
Reducing speed or stopping after high
speed driving.
Idling for a long period with the air
conditioning on in stopandgo traffic.
Towing a trailer.
NOTICE
Do not remove the thermostat in
the engine cooling system as this
may cause the engine to overheat.
The thermostat is designed to con-
trol the flow of coolant to keep the
temperature of the engine within
the specified operating range.
Do not continue driving with an
overheated engine. See “If your ve-
hicle overheats” on page 173 in
Section 4.
The tachometer indicates engine speed
in thousands of rpm (revolutions per
minute). Use it while driving to select
correct shift points and to prevent en-
gine lugging and overrevving.
Driving with the engine running too fast
causes excessive engine wear and poor
fuel economy. Remember, in most cases
the slower the engine speed, the greater
the fuel economy.
NOTICE
Do not let the indicator needle get
into the red zone. This may cause
severe engine damage.
Tachometer

’03 Corolla U (L/O 0201)
1232003 MY COROLLA_U (OM12744U)
Fan speed selector
Turn the knob to adjust the fan speed—to
the right to increase, to the left to de-
crease.
Temperature selector
Turn the knob to adjust the temperature—
to the right to warm, to the left to cool.
Air flow selector
Turn the knob to select the vents used for
air flow.1. Panel— Air flows mainly from the
instrument panel vents.
2. Bilevel— Air flows from both the floor
vents and the instrument panel vents.
3. Floor— Air flows mainly from the floor
vents.
4. Floor/Windshield— Air flows mainly
from the floor vents and windshield
vents.
Turning the air flow selector to the
floor/windshield position turns on the
defogging function with the purpose of
clearing the front view. This position allows the air intake to
select FRESH automatically. This is to
clean up the front view more quickly.
If you want to return the setting to
RECIRCULATE mode, press the air in-
take selector button once again.
Press the “A/C” button for dehumidified
heating or cooling. This setting clears
the front view more quickly.
If you turn the air flow selector to the
another position, the air intake mode
returns to FRESH mode automatically.
5. Windshield— Air flows mainly from the
windshield vents.
Turning the air flow selector to the
windshield position turns on the defog-
ging function with the purpose of clear-
ing the front view.
This position allows the air intake to
select FRESH automatically. This is to
clean up the front view more quickly.
If you want to return the setting to
RECIRCULATE mode, press the air in-
take selector button once again.
Press the “A/C” button for dehumidified
heating or cooling. This setting clears
the front view more quickly.

’03 Corolla U (L/O 0201)
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When driving on dusty roads, close all
windows. If dust thrown up by the ve-
hicle is still drawn into the vehicle after
closing the windows, it is recommended
that the air intake selector be set to
FRESH and the fan speed selector to
any setting except “OFF”.
If following another vehicle on a dusty
road, or driving in windy and dusty
conditions, it is recommended that the
air intake selector be temporarily set to
RECIRCULATE, which will close off the
outside passage and prevent outside
air and dust from entering the vehicle
interior.Heating
For best results, set controls to:
Fan speed— Any setting except “OFF”
Temperature— Towards red zone
Air intake—FRESH (outside air)
Air flow—FLOOR
Air conditioning—OFF
For quick heating, select recirculated
air for a few minutes. To keep the
windows from fogging, select fresh af-
ter the vehicle interior has been
warmed.
Press the “A/C” button on for dehumidi-
fied heating.
Choose floor/windshield air flow to heat
the vehicle interior while defrosting or
defogging the windshield. Air conditioning
For best results, set controls to:
Fan speed— Any setting except “OFF”
Temperature— Towards blue zone
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—ON
For quick cooling, select recirculated
air for a few minutes.
Ventilation
For best results, set controls to:
Fan speed— Any setting except “OFF”
Temperature— Towards blue zone
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—OFF

’03 Corolla U (L/O 0201)
1272003 MY COROLLA_U (OM12744U)
Defogging
The inside of the windshield
For best results, set controls to:Fan speed— Any setting except “OFF”
Temperature— Towards red zone to heat;
blue zone to cool
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
Turning the air flow selector to the wind-
shield or floor/windshield position turns on
the defogging function with the purpose of
clearing the front view.
When turning the air flow selector to wind-
shield or floor/windshield position, the air
intake selects FRESH automatically. This
is to clean up the front view more quickly.
If you want to return the setting to RE-
CIRCULATE mode, press the air intake
selector button once again.
Press the “A/C” button for dehumidified
heating or cooling. This setting clears the
front view more quickly.
If you turn the air flow selector to the
another position, the air intake mode re-
turns to FRESH mode automatically.
On humid days, do not blow cold air
on the windshield—the difference be-
tween the outside and inside tempera-
tures could make the fogging worse.
Defrosting
The outside of the windshield
For best results, set controls to:
Fan speed— Any setting except “OFF”
Temperature— Towards red zone
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
Turning the air flow selector to the wind-
shield or floor/windshield position turns on
the defrosting function with the purpose of
clearing the front view.
When turning the air flow selector to wind-
shield or floor/windshield position, the air
intake selects FRESH automatically. This
is to clean up the front view more quickly.
If you want to return the setting to RE-
CIRCULATE mode, press the air intake
selector button once again.
Press the “A/C” button for dehumidified
heating. This setting clears the front view
more quickly.
If you turn the air flow selector to the
another position, the air intake mode re-
turns to FRESH mode automatically.
To heat the vehicle interior while de-
frosting the windshield, choose
floor/windshield air flow.

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NOTICE
A large amount of unburned gases
flowing into the threeway catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only unleaded gasoline.
 Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three
way catalytic converter.
 Do not allow the engine to run at
idle speed for more than 20 min-
utes.
 Avoid racing the engine.
 Do not pushstart or pullstart your
vehicle.
 Do not turn off the ignition while
the vehicle is moving.
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel system could cause an ex-
tremely high threeway catalytic
converter temperature.
 If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a checkup as soon
as possible. Remember, your Toyota
dealer knows your vehicle and its
threeway catalytic converter sys-
tem best.
 To ensure that the threeway cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.CAUTION
Avoid inhaling the engine exhaust.
It contains carbon monoxide, which
is a colorless and odorless gas. It
can cause unconsciousness or even
death.
Make sure the exhaust system has
no holes or loose connections. The
system should be checked from
time to time. If you hit something,
or notice a change in the sound of
the exhaust, have the system
checked immediately.
Do not run the engine in a garage
or enclosed area except for the
time needed to drive the vehicle in
or out. The exhaust gases cannot
escape, making this a particularly
dangerous situation.
Do not remain for a long time in a
parked vehicle with the engine run-
ning. If it is unavoidable, however,
do so only in an unconfined area
and adjust the heating or cooling
system to force outside air into the
vehicle.
Engine exhaust cautions

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Keep the trunk lid closed while
driving. An open or unsealed trunk
lid may cause exhaust gases to be
drawn into the vehicle.
To allow proper operation of your
vehicle’s ventilation system, keep
the inlet grilles in front of the wind-
shield clear of snow, leaves, or oth-
er obstructions.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the trunk lid closed. Have
the cause immediately located and
corrected.
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume some engine oil during normal
engine operation. The causes of oil
consumption in a normal engine are as
follows.
Oil is used to lubricate pistons, piston
rings and cylinders. A thin film of oil
is left on the cylinder wall when a pis-
ton moves downwards in the cylinder.
High negative pressure generated when
the vehicle is decelerating sucks some
of this oil into the combustion chamber.
This oil as well as some part of the oil
film left on the cylinder wall is burned
by the high temperature combustion
gases during the combustion process.
Oil is also used to lubricate the stems
of the intake valves. Some of this oil
is sucked into the combustion chamber
together with the intake air and is
burned along with the fuel. High tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by highspeed driv-
ing and frequent acceleration and decel-
eration.
A new engine consumes more oil, since
its pistons, piston rings and cylinder walls
have not become conditioned.
When judging the amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately.
As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal amount of oil, the dipstick may not
show any drop in the oil level at all, even
after 1000 km (600 miles) or more. This
is because the oil is gradually becoming
diluted with fuel or moisture, making it
appear that the oil level has not changed.
Facts about engine oil
consumption

’03 Corolla U (L/O 0201)
1732003 MY COROLLA_U (OM12744U)
5. Start your engine in the normal way.After starting, run it at about 2000 rpm
for several minutes with the accelerator
pedal lightly depressed.
6. Carefully disconnect the cables in the exact reverse order: the negative cable
and then the positive cable.
7. Carefully dispose of the battery cover cloths—they may now contain sulfuric
acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is
not apparent (for example, lights left on),
you should have it checked. If your engine stalls while driving...
1. Reduce your speed gradually, keeping a straight line. Move cautiously off the
road to a safe place.
2. Turn on your emergency flashers.
3. Turn the ignition key to “ACC” or “LOCK”, and try starting the engine
again.
If the engine will not start, see “If your
vehicle will not start” on page 170 in this
section.
CAUTION
If the engine is not running, the pow-
er assist for the brakes and steering
will not work so steering and braking
will be much harder than usual.
If your engine coolant temperature
gauge indicates overheating, if you ex-
perience a loss of power, or if you hear
a loud knocking or pinging noise, the
engine has probably overheated. You
should follow this procedure... 1. Pull safely off the road, stop the ve- hicle and turn on your emergency
flashers. Put the transmission in “P”
(automatic) or neutral (manual) and ap-
ply the parking brake. Turn off the air
conditioning if it is being used.
2. If coolant or steam is boiling out of the radiator or reservoir, stop the engine.
Wait until the steam subsides before
opening the hood. If there is no coolant
boiling over or steam, leave the engine
running and make sure the electric
cooling fan is operating. If it is not,
turn the ignition off.
CAUTION
To help avoid personal injury, keep
the hood closed until there is no
steam. Escaping steam or coolant is
a sign of very high pressure.
If your engine stalls while
driving If your vehicle overheats

’03 Corolla U (L/O 0201)
2022003 MY COROLLA_U (OM12744U)
1. Power steering fluid reservoir
2. Engine oil level dipstick
3. Engine coolant reservoir
4. Engine oil filler cap
5. Brake fluid reservoir
6. Fuse block
7. Battery
8. Radiator
9. Electric cooling fan
10. Condenser
11. Windshield washer fluid tank
Engine compartment overview