2021 TOYOTA PRIUS Owners Manual (in English)

PRIUS_OM_OM47E09U_(U)
5216-3. Do-it-yourself maintenance
6
Maintenance and care
WARNING
■Used engine oil
● Used engine oil contains potentially harmful contaminants which may
cause skin disorders such as inflammation and skin cancer, so c are
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 sewe rs 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 a 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 v ehicle.
● Be sure the engine oil filler cap is properly tightened.

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PRIUS_OM_OM47E09U_(U)
6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “MAX” an d “MIN”
lines on the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“MAX” line
“MIN” line
If the level is on or below the
“MIN” line, add coolant up to the
“MAX” line. ( P. 656)
■
Power control unit coolant reservoir Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to
the “FULL” line. ( P. 658)
Coolant
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2
3
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2
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PRIUS_OM_OM47E09U_(U)
5236-3. Do-it-yourself maintenance
6
Maintenance and care
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-bora te coolant with
long-life hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -31 F [-35 C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deion-
ized water. (Minimum temperature: -44 F [-42 C])
For more details about coolant, contact your Toyota dealer.
■ If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit c oolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have your Toyota dealer test the cap and check for
leaks in the cooling system.
WARNING
■ When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir c aps.
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
■ When adding coolant
Coolant is neither plain water nor straight antifreeze. The cor rect mixture of
water and antifreeze 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 from damaging p arts or paint.

524
PRIUS_OM_OM47E09U_(U)
6-3. Do-it-yourself maintenance
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of
their condition, have your vehic le inspected by your Toyota dea ler.
Check the 12-volt battery as follows:
■12-volt battery exterior
Make sure that the 12-volt battery terminals are not corroded a nd
that there are no loose connecti ons, cracks, or loose clamps.
Terminals
Radiator and condenser
WARNING
■ When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and c ause seri-
ous injuries, such as burns.
■ When the electric cooling fans are operating
Do not touch the engine compartment.
With the power switch in ON mode, the electric cooling fans may automati-
cally start to run if the air conditioning is on and/or the coolant temperature
is high. Be sure the power switch is off when working near the electric cool-
ing fans or radiator grille.
12-volt battery

PRIUS_OM_OM47E09U_(U)
5256-3. Do-it-yourself maintenance
6
Maintenance and care
■When opening the cover of the positive (+) battery terminal
■ Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flam-
mable and explosive. Therefore, observe the following precautio ns before
recharging:
● If recharging with the 12-volt battery installed on the vehicle , be sure to dis-
connect the ground cable.
● Make sure the power switch on the charger is off when connectin g and dis-
connecting the charger cables to the 12-volt battery.
■ After recharging/reconnecting the 12-volt battery
●Unlocking the doors using the smart key system may not be possi ble imme-
diately after reconnecting the 12-volt battery. If this happens, use the wire-
less remote control or the mechanical key to lock/unlock the do ors.
● Start the hybrid system with the power switch in ACCESSORY mode . The
hybrid system may not start with the power switch turned off. However, the
hybrid system will operate normally from the second attempt.
● The power switch mode is recorded by the vehicle. If the 12-vol t battery is
reconnected, the vehicle will return the power switch mode to t he status it
was in before the 12-volt battery was disconnected. Make sure t o turn off
the power before disconnect the 12-volt battery. Take extra car e when con-
necting the 12-volt battery if the power switch mode prior to d ischarge is
unknown.
If the system will not start even after multiple attempts at al l methods above,
contact your Toyota dealer. While pushing the portion shown in the
illustration from both sides, lift the end of
the cover up.

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6-3. Do-it-yourself maintenance
WARNING
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric a cid and may
produce hydrogen gas which is flammable and explosive. To reduce the risk
of death or serious injury, take the following precautions while working on or
near the 12-volt battery:
● Do not cause sparks by touching the 12-volt battery terminals w ith tools.
● Do not smoke or light a match near the 12-volt battery.
● Avoid contact with eyes, skin and clothes.
● Never inhale or swallow electrolyte.
● Wear protective safety glasses when working near the 12-volt ba ttery.
● Keep children away from the 12-volt battery.
■ Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charg e the
12-volt battery in a garage or closed room where there is insufficient ventila-
tion.
■ How to recharge the 12-volt battery
Only perform a slow charge (5 A or less). The 12-volt battery m ay explode if
charged at a quicker rate.
■ Emergency measures regarding electrolyte
● If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and ge t immedi-
ate medical attention. If possible, continue to apply water wit h a sponge or
cloth while traveling to the nearest medical facility.
● If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical
attention immediately.
● If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the cloth-
ing and follow the procedure above if necessary.
● If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention
immediately.

PRIUS_OM_OM47E09U_(U)
5276-3. Do-it-yourself maintenance
6
Maintenance and care
WARNING
■When disconnecting the 12-volt battery
Do not disconnect the negative (-) terminal on the body side. T he discon-
nected negative (-) terminal may touch the positive (+) termina l, which may
cause a short and result in death or serious injury.
NOTICE
■ When recharging th e 12-volt battery
Never recharge the 12-volt battery while the hybrid system is o perating.
Also, be sure all accessories are turned off.

528
PRIUS_OM_OM47E09U_(U)
6-3. Do-it-yourself maintenance
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluidSlide and lift up the rubber
strip to partly remove it as
shown.
Disconnect the claws and
remove the service cover.
Brake fluid
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