2002 TOYOTA PRIUS cooling

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

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

218
CAUTION
Do not exceed 50 km/h (30 mph) or
the chain manufacturer ’s recom-
mended speed limit, whichever is
lower.
Drive carefully avoiding bumps,
holes, and sharp turns, which may
cause the vehicle to bounce.
Avoid sharp turns or lockedwheel
braking, as use of chains may ad-
versely affect vehicle handling.
When driving with chains installed,
be sure to drive carefully. Slow
down before entering the curves to
avoid losing control of the vehicle.
Otherwise an accident may occur.
NOTICE
Do not attempt to use a tire chain on
the compact spare tire, as it may re-
sult in damage to the vehicle as well
as the tire.
WHEN TO REPLACE YOUR WHEELS
If you have wheel damage such as
bending, cracks or heavy corrosion, the
wheel should be replaced.
If you fail to replace damaged wheels, the
tire may slip off the wheel or cause loss
of handling control.
WHEEL SELECTION
When replacing wheels, care should be
taken to ensure that the wheels are re-
placed by ones with the same load ca-
pacity, diameter, rim width, and offset.
This must be observed on compact spare
tire, too.
Correct replacement wheels are available
at your Toyota dealer.
A wheel of a different size or type may
adversely affect handling, wheel and bear-
ing life, brake cooling, speedometer/odom-
eter calibration, stopping ability, headlight
aim, bumper height, vehicle ground clear-
ance, and tire or snow chain clearance to
the body and chassis.Replacement with used wheels is not rec-
ommended as they may have been sub-
jected to rough treatment or high mileage
and could fail without warning. Also, bent
wheels which have been straightened may
have structural damage and therefore
should not be used. Never use an inner
tube in a leaking wheel which is designed
for a tubeless tire.
Replacing wheels

234
Overall length mm (in.) 4305 (169.5)
Overall width mm (in.) 1695 (66.7)
Overall height mm (in.) 1465 (57.6)*
Wheelbase mm (in.) 2550 (100.4)
Front tread mm (in.) 1475 (58.1)
Rear tread mm (in.) 1480 (58.2)
Vehicle capacity weight
(occupants + luggage)kg (lb.) 363 (800)
*: Unladen vehicle
Electric motor
Type: Permanent magnet motor (water cooling)
Rated output: 20 kW
Maximum output: 33.0/1040 − 5600 kW/rpm
Maximum torque: 350.0/0 − 400 N·m/rpm Model: 1NZ
−FXE
Type: 4 −cylinder in line, 4 cycle, gasoline
Bore and stroke, mm (in.): 75.0 x 84.7 (2.95 x 3.33)
Displacement, cm
3 (cu. in.):
1497 (91.4)
Dimensions and weight Engine

236
ENGINE LUBRICATION
Oil capacity (drain and refill), L (qt, lmp.
qt.):
With filter 3.7 (3.9, 3.3)
Without filter 3.4 (3.6, 3.0)
Oil grade: API grade SJ “Energy −Conserving”, SL
“Energy −Conserving” or ILSAC
multigrade engine oil is recommended.
Recommended oil viscosity (SAE):
oil05u
COOLING SYSTEM
Total capacity, L (qt., Imp. qt.): For gasoline engine 4.9 (5.2, 4.3)
For electric motor
and inverter and
converter 2.6 (2.7, 2.3)
Coolant type: “TOYOTA Long Life Coolant” or equiva-
lent
With ethylene− glycol type coolant for a
proper corrosion protection of aluminum
components
Do not use alcohol type antifreeze or plain
water alone.
AUXILIARY BATTERY
Open voltage at 20 C (68 F):
12.6 − 12.8 V Fully charged
12.2 − 12.4 V Half charged
11 . 5 − 11.9 V Discharged
[Voltage that is checked 20 minutes after
the key is removed with all the lights
turned off]
Charging rates: 3.5 A max.HYBRID TRANSAXLE
Fluid capacity, L (qt., Imp. qt.):
4.6 (4.9, 4.1)
Fluid type: Automatic transmission fluid Type T −IV
or equivalent

238
90p006a
Engine compartment
8. AM2 15 A: Starting system, multiport
fuel injection system/sequential multi-
port fuel injection system, hybrid ve-
hicle immobiliser system
9. THRO 15 A: Electronic throttle control
system
10. HEAD (RH) (Vehicles without DAY- TIME RUNNING LIGHT SYSTEM) or
HEAD LO (RH) (Vehicles with DAY-
TIME RUNNING LIGHT SYSTEM) 10
A: Right −hand headlight
11. HEAD HI (LH) (Vehicles without DAY- TIME RUNNING LIGHT SYSTEM) 10
A: Left −hand headlight (high beam)
90p007a
Instrument panel
12. BATT FAN 10 A: Battery cooling fan
13. ABS NO.3 20 A: Hydraulic brake
booster
14. HV 20 A: Hybrid system
15. EFI 15 A: Multiport fuel injection sys-
tem/sequential multiport fuel injection
system
16. HEAD (LH) (Vehicles without DAY- TIME RUNNING LIGHT SYSTEM) or
HEAD LO (LH) (Vehicles with DAY-
TIME RUNNING LIGHT SYSTEM) 10
A: Left −hand headlight
90p008a
Trunk
17. DOME 15 A: Audio system, mult −infor-
mation display, interior light, trunk light,
power window system, wireless remote
control system
18. TURNHAZ 10 A: Turn signal lights,
Emergency flasher
19. PANEL 5 A: Audio system, ashtray
light, headlight beam level control sys-
tem, emergency flasher
20. GAUGE 10 A: Gauge and meter, emer-
gency flasher, rear window defogger,
service reminder indicator and warning
buzzers, back− up light, power window
system, air c onditioning system

239
21. HTR 10 A: Air conditioning system
22. TAIL 7.5 A: Parking lights, tail lights,
license plate lights, side marker lights
23. ECUIG 5 A: Air conditioning system,
anti −lock brake system, electric power
steering, daytime running light system
24. STOP 15 A: Stop lights, high mounted
stoplights, anti −lock brake system
25. ACC 10 A: Anti−lock brake system
warning light, clock, audio system, mul-
ti −information display, shift lock system
26. WIPER 30 A: Windshield wiper
27. ECUB 7.5 A: Air conditioning system,
daytime running light system, electric
power steering system, hybrid vehicle
immobiliser system
28. CIG 15 A: Power outlet
29. WASHER 15 A: Washer
30. DOOR 30 A: Power door lock system
31. SRS ACC 10 A: SRS airbags, seat
belt pretensioners
32. OBD II 7.5 A: No circuit
33. PWR1 20 A: Power window system
34. AM1 5 A: “ACC”, “CIG”, “SRS ACC”,
“WASHER”, “HTR”, “WIPER”, “ECU −IG”
and “GAUGE” fuses
35. DC/DCS 5 A: Inverter and converter 36. HTR NO.3 50 A:
Air conditioning sys-
tem
37. EMPS 50 A: Electric power steering
38. ABS NO.1 40 A: Anti−lock brake sys-
tem
39. MF HEAD 30 A: Daytime running light
system
40. HTR 50 A: Air conditioning system
41. RDI 30 A: Electric cooling fan
42. ABS NO.2 30 A: Hydraulic brake
booster