2021 TOYOTA PRIUS Owners Manual (in English)

891-4. Hybrid system
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For safety and security
There is an air intake vent under
the right side of the rear seat for
the purpose of cooling the hybrid
battery (traction battery). If the
vent is blocked, charging/dis-
charging of the hybrid battery
(traction battery) may become lim-
ited.
When a certain level of impact is detected by the impact sensor , the
emergency shut off system blocks the high voltage current and stops
the fuel pump to minimize the ri sk of electrocution and fuel leakage. If
the emergency shut off system activates, your vehicle will not restart.
To restart the hybrid system , contact your Toyota dealer.
A message is automatically displ ayed when a malfunction occurs in
the hybrid system or an improper operation is attempted.
If a warning message is shown on
the multi-information display, read
the message and follow the
instructions.
Hybrid battery (traction battery) air intake vent
Emergency shut off system
Hybrid warning message

901-4. Hybrid system
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■If a warning light comes on, a warning message is displayed, or the
12-volt battery is disconnected
The hybrid system may not start. In this case, try to start the system again. If
the “READY” indicator does not come on, contact your Toyota dea ler.
■ Running out of fuel
When the vehicle has run out of fuel and the hybrid system cann ot be started,
refuel the vehicle with at least enough gasoline to make the lo w fuel level
warning light ( P. 594) go off. If there is only a small amount of fuel, the
hybrid system may not be able to start. (The standard amount of fuel is about
2.0 gal. [7.5 L, 1.7 Imp.gal.], when the vehicle is on a level surface. This value
may vary when the vehicle is on a slope. Add extra fuel when th e vehicle is
inclined.)
■ Electromagnetic waves
●High voltage parts and cables on hybrid vehicles incorporate el ectromag-
netic shielding, and therefore emit approximately the same amount of elec-
tromagnetic waves as conventional gasoline powered vehicles or home
electronic appliances.
● Your vehicle may cause sound interference in some third party-p roduced
radio parts.
■ Hybrid battery ( traction battery)
The hybrid battery (traction battery) has a limited service life. The lifespan of
the hybrid battery (traction battery) can change in accordance with driving
style and driving conditions.
■ Starting the hybrid system in a n extremely cold environment
When the hybrid battery (traction battery) is extremely cold (b elow approxi-
mately -22°F [-30°C]) under the influence of the outside temper ature, it may
not be possible to start the hybrid system. In this case, try to start the hybrid
system again after the temperature of the hybrid battery increases due to the
outside temperature increase etc.

911-4. Hybrid system
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For safety and security
WARNING
■High voltage precautions
This vehicle has high voltage DC and AC systems as well as a 12 -volt sys-
tem. DC and AC high voltage is very dangerous and can cause sev ere
burns and electric shock that may result in death or serious in jury.
● Never touch, disassemble, remove or replace the high voltage pa rts,
cables or their connectors.
● The hybrid system will become hot after starting as the system uses high
voltage. Be careful of both the high voltage and the high tempe rature, and
always obey the warning labels attached to the vehicle.
● Never try to open the service plug
access hole located under the right side
of the rear seat. The service plug is
used only when the vehicle is serviced
and is subject to high voltage.

921-4. Hybrid system
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WARNING
■Road accident cautions
Observe the following precautions to reduce the risk of death o r serious
injury:
● Pull your vehicle off the road, apply the parking brake, shift the shift posi-
tion to P, and turn the hybrid system off.
● Do not touch the high voltage parts, cables and connectors.
● If electric wires are exposed inside or outside your vehicle, an electric
shock may occur. Never touch exposed electric wires.
● If a fire occurs in the hybrid vehicle, leave the vehicle as soon as possible.
Never use a fire extinguisher that is not meant for electric fires. Using even
a small amount of water may be dangerous.
● If your vehicle needs to be towed, do so with front wheels (2WD models)
or four wheels (AWD models) raised. If the wheels connected to the elec-
tric motor (traction motor) are on the ground when towing, the motor may
continue to generate electricity. This may cause a fire. ( P. 584)
● Carefully inspect the ground under the vehicle. If you find that liquid has
leaked onto the ground, the fuel system may have been damaged. Leave
the vehicle as soon as possible.
AWD models
● If a fluid leak occurs, do not touch the fluid as it may be str ong alkaline
electrolyte from the hybrid battery (traction battery). If it c omes into contact
with your skin or eyes, wash it off immediately with a large am ount of water
or, if possible, boric acid solution. Seek immediate medical attention.
2WD models
● Do not touch the battery if liquid is leaking from or adhering to it.
If electrolyte (carbonic-based organic electrolyte) from the hy brid battery
(traction battery) comes into contact with the eyes or skin, it could cause
blindness or skin wounds. In the unlikely event that it comes into contact
with the eyes or skin, wash it off immediately with a large amount of water,
and seek immediate medical attention.
● If electrolyte is leaking from the hybrid battery (traction bat tery), do not
approach the vehicle.
Even in the unlikely event that the hybrid battery (traction ba ttery) is dam-
aged, the internal construction of the battery will prevent a l arge amount of
electrolyte from leaking out. However, any electrolyte that doe s leak out
will give off a vapor. This vapor is an irritant to skin and eyes and could
cause acute poisoning if inhaled.
● Do not bring burning or high-tem perature items close to the electrolyte.
The electrolyte may ignite and cause a fire.

931-4. Hybrid system
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For safety and security
WARNING
■Hybrid battery (traction battery)
● 2WD models: Your vehicle contains a sealed lithium-ion battery.
● Never resell, hand over or modify the hybrid battery. To preven t accidents,
hybrid batteries that have been removed from a disposed vehicle are col-
lected through Toyota dealer. Do not dispose of the battery yourself.
Unless the battery is properly collected, the following may occ ur, resulting
in death or serious injury:
• The hybrid battery may be illegally disposed of or dumped, and it is haz-
ardous to the environment or someone may touch a high voltage p art,
resulting in an electric shock.
• The hybrid battery is intended to be used exclusively with you r hybrid
vehicle. If the hybrid battery is used outside of your vehicle or modified
in any way, accidents such as electric shock, heat generation, smoke
generation, an explosion and electrolyte leakage may occur.
When reselling or handing over your vehicle, the possibility of an accident
is extremely high because the person receiving the vehicle may not be
aware of these dangers.
● If your vehicle is disposed of without the hybrid battery havin g been
removed, there is a danger of serious electric shock if high vo ltage parts,
cables and their connectors are touched. In the event that your vehicle
must be disposed of, the hybrid battery must be disposed of by your
Toyota dealer or a qualified service shop. If the hybrid battery is not dis-
posed of properly, it may cause electric shock that can result in death or
serious injury.

941-4. Hybrid system
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NOTICE
■Hybrid battery (traction battery) air intake vent
● Make sure not to block the air intake vent with anything, such as a seat
cover, plastic cover, or luggage. If the vent is blocked, the charging/dis-
charging of the hybrid battery (traction battery) may become li mited.
● When dust etc. has accumulated in the air intake vent, clean it with a vac-
uum cleaner to prevent the vent from clogging.
● Do not get water or foreign materials in the air intake vent as this may
cause a short circuit and damage the hybrid battery (traction b attery).
● Do not carry large amounts of water such as water cooler bottle s in the
vehicle. If water spills onto the hybrid battery (traction batt ery), the battery
may be damaged. Have the vehicle inspected by your Toyota deale r.
● There is a filter installed to the air intake vent. When the fi lter remains
noticeably dirty even after cleaning the air intake vent, filte r cleaning or
replacement is recommended. For information regarding filter cl eaning or
replacement, refer to P. 551.
● If “Maintenance required for Traction battery cooling parts See owner’s
manual” is shown on the multi-information display, the air intake vent and
filter may be clogged. Refer to P. 551 for information on how to clean the
air intake vent.

951-5. Theft deterrent system
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For safety and security
Immobilizer system
The indicator light flashes after
the power switch has been turned
off to indicate that the system is
operating.
The indicator light stops flashing
after the power switch has been
turned to ACCESSORY or ON
mode to indicate that the system
has been canceled.
■System maintenance
The vehicle has a maintenance-free type immobilizer system.
■ Conditions that may cause the system to malfunction
●If the grip portion of the key is in contact with a metallic ob ject
● If the key is in close proximity to or touching a key registered to the security
system (key with a built-in transponder chip) of another vehicle
The vehicle’s keys ha ve built-in transponder chips that prevent
the hybrid system from starting if a key has not been previousl y
registered in the vehic le’s on-board computer.
Never leave the keys inside the vehicle when you leave the vehi-
cle. This system is designed to help prevent vehicle theft but does not
guarantee absolute security against all vehicle thefts.

961-5. Theft deterrent system
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Certifications for the immobilizer system
For vehicles sold in the U.S.A., Hawaii, American Samoa, Guam, Saipan
and Puerto Rico
For vehicles sold in Canada
NOTICE
■ To ensure the system operates correctly
Do not modify or remove the system. If modified or removed, the proper
operation of the system cannot be guaranteed.