engine TOYOTA PRIUS 2010 3.G Owner's Guide

418 4-3. Do-it-yourself maintenance
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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.

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NOTICE
■
If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear
due to dirt in the air. Also a backfire could cause a fire in the engine compart-
ment.

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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)

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Engine oilWith the engine at operating temperature and turned off, check the oil
level on the dipstick.
■ Checking the engine oil
Park the vehicle on level ground. After turning off the hybrid
system, wait more than 5 minutes for the oil to drain back into
the bottom of the engine.
Hold a rag under the end and
pull the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end, pull the dipstick out and check
the oil level.
Wipe the dipstick and reinsert it fully. Low
Full
STEP1
STEP2
STEP3
STEP4
STEP5
STEP6
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■
Adding engine oil
If the oil level is below or near
the low level mark, add engine
oil of the same type as already in
the engine.
Make sure to check the oil type and prepare the items needed before
adding oil.
Remove the oil filler cap.
Add engine oil slowly, checking the dipstick.
Install the filler cap, turning it clockwise.
Engine oil selectionP. 560
Oil quantity
(Low  Full) 1.6 qt. (1.5 L, 1.3 Imp. qt.)
Items Clean funnel
STEP1
STEP2
STEP3

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■Engine oil consumption
● The amount of engine oil consumed depends on the oil viscosity, the
quality of the oil and the way the vehicle is driven.
● More oil is consumed under driving conditions such as high speeds, fre-
quent acceleration and deceleration.
● A new engine consumes more oil.
● When judging the amount of oil consumption, keep in mind that the oil
may have become diluted, making it difficult to judge the true level accu-
rately.
● Oil consumption: Max. 1.1 qt./600 miles, 0.9 Imp. qt./600 miles (1.0 L per
1000 km).
● If the vehicle consumes more than 1.1 qt. (1.0 L, 0.9 Imp.qt.) every 600
miles (1000 km), contact your Toyota dealer.
■ After changing the engine oil (U.S.A. only)
The oil change system should be rese t. Perform the following steps:
Turn the “POWER” switch OFF with the trip meter A shown.
Turn the “POWER” switch ON with the MPH or km/h button 
( P. 183) held down.
Keep pressing the button until the odometer indicates “000000” and
the multi-information display indicates that the reset is complete.
STEP1
STEP2
STEP3

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CAUTION
■
Used engine oil
● Used engine oil contains potentially harmful contaminants which may
cause skin disorders such as inflammation or skin cancer, so care should
be taken to avoid prolonged and repeated contact. To remove used engine
oil from your skin, wash thoroughly with soap and water.
● Dispose of used oil and filters only in a safe and acceptable manner. Do
not dispose of used oil and filters in household trash, in sewers or onto the
ground. 
Call your Toyota dealer, service station or auto parts store for information
concerning recycling or disposal.
● Do not leave used engine oil within the reach of children.
NOTICE
■To prevent serious engine damage
Check the oil level on regular basis.
■ When replacing the engine oil
● Be careful not to spill engine oil on the vehicle components.
● Avoid overfilling, or the engine could be damaged.
● Check the oil level on the dipstick every time you refill the vehicle.
● Be sure the engine oil filler cap is properly retightened.

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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.
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■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.

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■
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.

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If the washer fluid level is at
“LOW”, add washer fluid.
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STEP3
CAUTION
■
When refilling the washer fluid
Do not refill the washer fluid when the hybrid system is hot or operating, as
the washer fluid contains alcohol and may catch fire if spilled on the hybrid
system etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid. 
Doing so may cause streaking on the vehicle’s painted surfaces.
■ Diluting washer fluid
Dilute washer fluid with water as necessary. 
Refer to the freezing temperatures listed on the washer fluid tank.