cooling TOYOTA PRIUS 2010 3.G Owners Manual

31
1-1. Hybrid system
1
Before driving
PRIUS_U (OM47668U) U.S.A.
■
Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibration even though the vehicle is able
to move. Always push the “P” position switch when parked.
The following sounds or vibrations may occur when the hybrid system is
operating, and are not a malfunction.
● Motor sounds may be heard from the engine compartment.
● Sounds may be heard from the hybrid battery (traction battery) behind
the rear seat when the hybrid system starts or stops.
● Sounds from the hybrid system may be heard when the back door is
open.
● Sounds may be heard from the transmission when the gasoline engine
starts or stops, when driving at low speeds, or during idling.
● Engine sounds may be heard when accelerating sharply.
● Sounds may be heard due to regenerative brake when you press the
brake pedal or release the accelerator pedal.
● Vibration may be felt when the gasoline engine starts or stops.
● You may hear cooling fan sounds coming from the air intake vents behind
the rear seat.
■ Maintenance, repair, recycling, and disposal
Contact your Toyota dealer regarding maintenance, repair, recycling and dis-
posal. Do not dispose of the vehicle yourself.

33
1-1. Hybrid system
1
Before driving
PRIUS_U (OM47668U) U.S.A.
■
Hybrid battery air vent
There is an air intake vent on the
side of the rear right seatback for
the purpose of cooling the hybrid
battery (traction battery). If the
vent becomes blocked, the
hybrid battery may overheat,
leading to a reduction in hybrid
battery output.
Emergency shut off system
The emergency shut off system blocks off the high voltage current
and stops the fuel pump to minimize the risk of electrocution and fuel
leakage when a certain level of impact is detected by the impact sen-
sor. If the emergency shut off system activates, your vehicle will not
restart. To restart the hybrid system, contact your Toyota dealer.

418 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
CAUTION
The engine compartment contains many mechanisms and fluids that may
move suddenly, become hot, or become electrically energized. To avoid death
or serious injury observe the following precautions.
■When working on the engine compartment
● Keep hands, clothing, and tools away from the moving fan.
● Be careful not to touch the engine, power control unit, radiator, exhaust
manifold, etc. right after driving as they may be hot. Oil and other fluids
may also be hot.
● Do not leave anything that may burn easily, such as paper or rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes
are flammable.
● Never touch, disassemble, remove or replace the high voltage parts,
cables and their connectors. It can cause severe burns or electric shock
that may result in death or serious injury.
● When the hybrid system is operating with the “READY” indicator on, the
engine may suddenly start in some cases. When you inspect the engine
compartment, be sure to turn off the hybrid system.
■ When working near the electric cooling fan or radiator grille
Be sure the “POWER” switch is OFF. 
With the “POWER” switch in ON mode, the electric cooling fan may automat-
ically start to run if the air conditioning is on and/or the coolant temperature
is high. ( P. 432)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from
getting in the eyes.

425
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
Engine compar tment
■12 volt battery
 P. 436
Engine coolant reservoir 
(  P. 430)
Engine oil level dipstick 
(  P. 426)
Engine oil filler cap 
(  P. 427)
Power control unit coolant
reservoir ( P. 430)Brake fluid reservoir 
(  P. 432)
Fuse box ( P. 462)
Radiator ( P. 432)
Condenser ( P. 432)
Electric cooling fans
Washer fluid tank 
( P. 434)

430 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
Engine/power control unit coolantThe coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Engine coolant reservoir Reservoir cap
“FULL”
“LOW”
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
Power control unit coolant reservoirReservoir cap
Full
Low
If the level is on or below the “L”
line, add coolant up to the “F” line.
ITO43P111
■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock
and water pump. 
If you cannot find a leak, have your Toyota dealer pressure test the cap and
check for leaks in the cooling system.

431
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
■
Coolant selection
Only use “Toyota Super Long Life Coolant” or similar high quality ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant
with long-life hybrid organic acid technology.
U.S.A.: “Toyota Super Long Life Coolant” is a mixture of 50 % coolant and 50 % deionized water. (Enabled: -31 F [-35 C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55 % coolant and 45 % deionized water. (Enabled: -44 F [-42 C])
For more details about engine coolant, contact your Toyota dealer.
CAUTION
■ When the hybrid system is hot
Do not remove the coolant reservoir cap. 
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing burns or other injuries.
NOTICE
■ When adding the coolant
Coolant is neither plain water not straight antifreeze. The correct mixture of
water and anti freeze must be used to provide proper lubrication, corrosion
protection and cooling. Be sure to read the antifreeze or coolant label.
■ If you spill coolant
Be sure to wash it off with water to prevent it damage to parts or paint.

465
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
Fuse layout and amperage ratings
■ Engine compartment
FUSEAmpereCircuit
1 HTR 50A Air conditioning system
2 RDI 30A Electric cooling fans
3 CDS 30A Electric cooling fans
4 S-HORN 10A No circuit
5 ENG W/P 30A Cooling system
6 ABS MAIN
NO.2 7.5A Anti-lock brake system
7 H-LP CLN 30A Headlight cleaner
8 AMP 30A Audio system
9 IGCT 30A PCU, IGCT NO.2, IGCT NO.3
10 DC/DC-S 5A Inverter and converter
11 P CON MAIN 7.5A Parking control system, transmis-
sion
ITO43P132
1
2
3
456 7
891011 12
13 14
15 16
17 18
19 20 21 22
2324
25 26 27 28 29 30 31 32 33 34
35 36 37 38 39 40

467
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
FUSEAmpereCircuit
27 MIR HTR 10A Outside rear view mirror defoggers
28 RAD NO.1 15A Audio system, navigation system
29 DOME 10ADoor courtesy lights, personal
lights, interior lights, front foot
lights, vanity lights, inside rear
view mirror, garage door opener,
electric power steering
30 ECU-B 7.5ASmart key system, multiplex com-
munication system, personal
lights, gauges and meters
31 H-LP LH HI 10A Left-hand headlight (high beam)
32 H-LP RH HI 10A Right-hand headlight (high beam)
33 EFI NO.2 10AMultiport fuel injection system/
sequential multiport fuel injection
system
34 IGCT NO.3 10A Cooling system
35 SPARE 30A Spare fuses
36 SPARE 15A Spare fuses
37 SPARE 7.5A Spare fuses
38 EFI MAIN 20AMultiport fuel injection system/
sequential multiport fuel injection
system, EFI NO.2
39 BATT FAN 10A Battery cooling fan
40 IG2 20AMultiport fuel injection system/
sequential multiport fuel injection
system, MET-IGN, IGN, power
windows

469
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
FUSEAmpereCircuit
15 P FR DOOR 25A Power windows
16 D FR DOOR 25A Power windows
17 DOOR RR 25A Power windows
18 DOOR RL 25A Power windows
19 S/ROOF 30A Electric moon roof
20 ECU-IG NO.1 10A Electric cooling fans, multiplex
communication system
21 ECU-IG NO.2 10A Driver support system, Pre-Colli-
sion System, LKA system, inside
rear view mirror, garage door
opener, yaw rate & G sensor,
brake system, electric power
steering, navigation system, elec-
tric moon roof, tire pressure warn-
ing system, seat belt
pretensioners, audio system,
emergency flashers, turn signal
lights, windshield wipers, headlight
cleaner
22 GAUGE 10A Headlight leveling system, front
passenger’s seat belt reminder
light, gauges and meters
23 A/C 10A Air conditioning system, Solar
Ventilation System, Remote Air
Conditioning System
24 WASHER 15A Windshield washer

5
When trouble arises
547
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
NOTICE
■
To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12 volt
battery from another vehicle in an emergency. It cannot be used to jump start
another vehicle.
■ When handling jumper cables
Be careful that the jumper cables do not become tangled in the cooling fan
or any of the belts when connecting or disconnecting them.