2003 TOYOTA HIGHLANDER cooling

’03 HIGHLANDER_U (L/O 0208)
1032003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
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 219 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.
This meter displays the odometer and
two trip meters.
1. Odometer—Shows the total distance the vehicle has been driven.
2. Two trip meters—Show two different distances independently driven since
the last time each trip meter was set
to zero.
You can use one trip meter to calculate
the fuel economy and the other to
measure the distance on each trip. All
trip meter data is cancelled if the elec-
trical power source is disconnected.
Tachometer Odometer and two trip meters

’03 HIGHLANDER_U (L/O 0208)
1542003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
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— To w a r d s WARM
(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— To w a r d s COLD
(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— To w a r d s COLD
(blue zone)
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—OFF

’03 HIGHLANDER_U (L/O 0208)
1612003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
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:
For automatic operation—
Press in the “AUTO” button.
Temperature— To the desired
temperature
Air intake—FRESH (outside air)
Air conditioning—OFF
For manual operation—
Fan speed— To the desired fan speed
Temperature— To w a r d s WARM
(to the right)
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:
For automatic operation—
Press in the “AUTO” button.
Temperature— To the desired
temperature
Air intake—FRESH (outside air)
Air conditioning—ON
For manual operation—
Fan speed— To the desired fan speed
Temperature— To w a r d s COLD
(to the left)
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—ON
For quick cooling, select recirculated
air for a few minutes.

’03 HIGHLANDER_U (L/O 0208)
1892003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
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 systems 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

’03 HIGHLANDER_U (L/O 0208)
1902003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
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.
Keep the back door closed while
driving. An open or unsealed back
door may cause exhaust gases to
be drawn into the vehicle.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the back door 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 HIGHLANDER_U (L/O 0208)
2192003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
Do not connect it to or near any part
that moves when the engine is
cranked.
CAUTION
When making the connections, to
avoid serious injury, do not lean over
the battery or accidentally let the
jumper cables or clamps touch any-
thing except the correct battery termi-
nals or the ground.
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 at your Toyota
dealer. 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 216.
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”
and apply 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 HIGHLANDER_U (L/O 0208)
2522003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
1. Engine coolant reservoir
2. Power steering fluid reservoir
3. Engine oil filler cap
4. Engine oil level dipstick
5. Brake fluid reservoir
6. Fuse blocks
7. Battery
8. Radiator
9. Condenser
10. Electric cooling fans
11. Windshield and rear window washer fluid tank
Engine compartment overview
2AZFE engine

’03 HIGHLANDER_U (L/O 0208)
2532003 HIGHLANDER from Aug. ’02 Prod. (OM48441U)
1. Engine coolant reservoir
2. Power steering fluid reservoir
3. Engine oil level dipstick
4. Engine oil filler cap
5. Brake fluid reservoir
6. Fuse blocks
7. Battery
8. Radiator
9. Condenser
10. Electric cooling fans
11. Windshield and rear window washer fluid tank

1MZFE engine