2002 TOYOTA PRIUS radiator cap

12
The hybrid system automatically con-
trols the level of electrical power re-
maining in the hybrid vehicle battery.
With the selector lever in a position
other than “N”, electricity is generated
and charging occurs when the level of
electrical power in the hybrid vehicle
battery decreases. It is unnecessary to
charge the hybrid vehicle battery from
outside.
INFORMATION:
The gasoline engine starts and stops
automatically. (It stops during a low
load driving, deceleration or when the
vehicle stopped.)
If the “READY” light remains on, you
can start your vehicle using the electric
motor even with the gasoline engine
stopped.
The gasoline engine may not stop auto-
matically in the following conditions:
 During under gasoline engine warm
up
 During hybrid vehicle battery charg-
ing
 When the air conditioning is used in
the “MAX” mode, the gasoline engine
is frequently used. If the output control warning light ()
comes on in the instrument cluster, the
hybrid vehicle battery temperature is
low or high, or the hybrid vehicle bat-
tery capacity is decreased with the se-
lector lever at “R” during driving. As it
does not indicate the failure of the sys-
tem, you can continue driving but avoid
hard acceleration because the power is
insufficient (which is caused by the bat-
tery power deterioration).
The vehicle runs in combination with
the gasoline and electric power. Pay
special attention to the following items.
Be careful of a high voltage and high
temperature.
Your vehicle is equipped with the orange
colored cables connected to the hybrid
vehicle battery which contain a high volt-
age (about 300 V) and to other high volt-
age parts.
CAUTION
Do not touch or come in contact with
orange cables or battery terminals.
Electric shock may cause serious in-
jury or death. Read all caution labels.
A electric motor, coolant radiator and
some other parts reach high temperature
when you are driving. Caution labels are
applied to these parts. Carefully observe
the instructions on these caution labels.
Precautions for use

172
If your hybrid system 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 switch to ”OFF” posi- tion, and try starting the hybrid system
again.
If the hybrid system will not start, see “If
your vehicle will not start” on page 168.
CAUTION
If the hybrid system is not operating,
the power assist for the brakes and
steering will not work so steering and
braking will be much harder than usu-
al.
If your high coolant temperature warn-
ing light comes on, if you experience a
loss of power, or if you hear a loud
knocking or pinging noise, the hybrid
system 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 hybrid
system. Wait until the steam subsides
before opening the hood. If there is no
coolant boiling over or steam, leave the
hybrid system 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.
3. Look for obvious coolant leaks from theradiator, hoses, and under the vehicle.
However, note that water draining from
the air conditioning is normal if it has
been used.
CAUTION
When the hybrid system is running,
keep hands and clothing away from
the moving fan and engine drive
belts.
4. If the coolant is leaking, stop the hy-brid system immediately. Call a Toyota
dealer for assistance.
5. If there are no obvious leaks, check the coolant reservoir. If it is dry, add
coolant to the reservoir while the hy-
brid system is running. Fill it about half
full.
CAUTION
Do not attempt to remove the radiator
cap when the hybrid system and ra-
diator are hot. Serious injury could
result from scalding hot fluid and
steam blown out under pressure.
If your hybrid system stalls
while driving If your vehicle overheats

200
Engine compartment overview
1. Engine coolant reservoir
2. Fuse blocks
3. Brake fluid reservoir
4. Engine oil filler cap
5. Inverter reservoir tank
6. Windshield washer fluid tank
7. Radiator and condenser
8. Engine oil level dipstick
9. Auxiliary battery
81p001f

202
If you perform maintenance by yourself,
be sure to follow the correct procedure
given in this Section.
You should be aware that improper or in-
complete servicing may result in operating
problems.
Performing do−it−yourself maintenance
during the warranty period may affect your
warranty coverage. Read the separate
Toyota Warranty statement for details and
suggestions.
This Section gives instructions only for
those items that are relatively easy for an
owner to perform. As explained in Section
7, there are still a number of items that
must be done by a qualified technician
with special tools.
For information on tools and parts for do −
it −yourself maintenance, see ”Parts and
tools” on page 205 in this Section.
Utmost care should be taken when work-
ing on your vehicle to prevent accidental
injury. Here are a few precautions that
you should be especially careful to ob-
serve:CAUTION
When the hybrid system is on, keep
hands, clothing, and tools away
from the moving fan and engine
drive belts. (Removing rings,
watches, and ties is advisable.)
Right after driving, the engine
compartment—the engine, radiator,
exhaust manifold and spark plug
boots, etc.—will be hot. So be care-
ful not to touch them. Oil, fluids
and spark plugs may also be hot.
If the hybrid system is hot, do not
remove the radiator cap or loosen
the drain plugs to prevent burning
yourself.
Do not smoke, cause sparks or al-
low open flames around fuel or the
batteries. Their fumes are flam-
mable.
When the hybrid system is operat-
ing with the “READY” light on, the
engine is automatically started in
some case. When you inspect the
engine compartment, be sure to
turn the ignition switch to “OFF”
position.
Do not get under your vehicle with
just the body jack supporting it. Al-
ways use automotive jack stands or
other solid supports.
Be sure that the ignition is off if
you work near the electric cooling
fans or radiator grille. With the
ignition on, the electric cooling fans
will automatically start to run if the
engine coolant temperature is high
and/or the air conditioning is on.
Use eye protection whenever you
work on or under your vehicle
where you may be exposed to fly-
ing or falling material, fluid spray,
etc.
Be extremely cautious when work-
ing on the batteries. It contains poi-
sonous and corrosive sulfuric acid
or strong alkali.
Warning: Battery posts, terminals and
related accessories contain lead and
lead compounds, chemicals known to
the State of California to cause can-
cer and reproductive harm. Wash
hands after handling.
Doityourself service
precautions

210
Look at the seethrough coolant reser-
voir when the hybrid system is cold.
The coolant level is satisfactory if it is
between the “FULL” and “LOW” lines
on the reservoir. If the level is low, add
ethyleneglycol type coolant for a prop-
er corrosion protection of aluminum
components.
The coolant level in the reservoir will vary
with hybrid system temperature. However,
if the level is on or below the “LOW” line,
add coolant. Bring the level up to the
“FULL” line.
Always use ethylene−glycol type coolant
for a proper corrosion protection of alumi-
num components. See information in the
next column.
If the coolant level drops within a short
time after replenishing, there may be a
leak in the system. Visually check the
radiator, hoses, radiator cap and drain
cock and water pump.
If you can find no leak, have your Toyota
dealer test the cap pressure and check
for leaks in the cooling system.CAUTION
To prevent burning yourself, do not
remove the radiator cap when the en-
gine is hot.
Coolant type selection
Use of improper coolants may damage
your cooling system. Your coolant must
contain ethylene− glycol type coolant for a
proper corrosion protection of your hybrid
system that contains aluminum compo-
nents. Use “TOYOTA Long Life Coolant”
or equivalent.
In addition to preventing freezing and sub-
sequent damage to the hybrid system, this
type of coolant will also prevent corrosion.
Further supplemental inhibitors or additives
are neither needed nor recommended.
Read the coolant container for information
on freeze protection. Follow the manufac-
turer’s directions for how much to mix
with plain water (preferably demineralized
water of distilled water). The total capacity
of the cooling system is given on page
236 in Section 9. We recommend to use 50% solution for
your Toyota, to provide protection down to
about
−35 °C ( −31 °F). When it is extremely
cold, to provide protection down to about
− 50 °C ( −58 °F), 60% solution is recom-
mended. Do not use more than 70% solu-
tion for better coolant performance.NOTICE
Do not use alcohol type antifreeze or
plain water alone.
Checking the coolant level

211
If any of the above parts are extremely
dirty or you are not sure of their condi-
tion, take your vehicle to Toyota dealer.
CAUTION
To prevent yourself from burning, be
careful not to touch the radiator or
condenser when the engine is hot.
NOTICE
To prevent damage to the radiator
and condenser, do not perform the
work by yourself.
Checking brake fluid
82p002a
To check the fluid level, simply look at
the seethrough reservoir. The level
should be between the ”MAX” and
”MIN” lines on the reservoir.
It is normal for the brake fluid level to go
down slightly as the brake pads wear or
when the fluid level in the accumulator is
high.
If the reservoir needs frequent refueling,
it may indicate a serious mechanical prob-
lem.If the level is low, add SAE J1703 or
FMVSS No. 116 DOT 3 brake fluid to
the brake reservoir.
Refilling brake fluid:
1. Turn the ignition switch off.
2. Depress the brake pedal more than 40 times.
3. Remove the reservoir cap by hand. Add brake fluid up to the ”MAX” line.
If you do not follow the procedure above,
the reservoir may overflow.
Use only newly opened brake fluid. Once
opened, brake fluid absorbs moisture from
the air, and excess moisture can cause a
dangerous loss of braking.
CAUTION
Take care when filling the r eservoir
because brake fluid can harm your
eyes and damage painted surfaces. If
fluid gets in your eyes, flush your
eyes with clean water immediately. If
you still feel uncomfortable with your
eyes, go to the doctor.
Checking the radiator and
condenser