2021 TOYOTA PRIUS Owners Manual (in English)

6497-2. Steps to take in an emergency
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When trouble arises
■Stopping the hybrid system
Set the parking brake, shift the shift position to P and press the power switch
as you normally do when stopping the hybrid system.
■ Replacing the key battery
As the above procedure is a temporary measure, it is recommende d that the
electronic key battery be replaced immediately when the battery is depleted.
( P. 560)
■ Changing power switch modes
Release the brake pedal and press the power switch in step abo ve. The
hybrid system does not start and modes will be changed each tim e the switch
is pressed. ( P. 247)
■ When the electronic key does not work properly
●Make sure that the smart key system has not been deactivated in the cus-
tomization setting. If it is off, turn the function on.
(Customizable features: P. 690)
● Check if battery-saving mode is set. If it is set, cancel the f unction.
( P. 198)
WARNING
■ When using the mechanical key and operating the power windows o r
moon roof (if equipped)
Operate the power window or moon roof after checking to make su re that
there is no possibility of any passenger having any of their body parts
caught in the window or moon roof.
Also, do not allow children to operate the mechanical key. It is possible for
children and other passengers to get caught in the power window or moon
roof.
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7-2. Steps to take in an emergency
If the 12-volt batter y is discharged
If you have a set of jumper (or booster) cables and a second vehicle
with a 12-volt battery, you can jump start your vehicle by foll owing the
steps below.
Open the hood. ( P. 515)
Remove the engine cover.
Pull up the both ends of the cover
vertically.
The following procedures may be used to start the hybrid sys-
tem if the vehicle’s 12-volt battery is discharged.
You can also call your Toyota de aler or a qualified repair shop.
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6517-2. Steps to take in an emergency
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When trouble arises
Connect the jumper cables according to the following procedure:Connect a positive jumper cable clamp to the positive (+) batte ry
terminal on your vehicle.
Connect the clamp on the other end of the positive cable to the
positive (+) battery termi nal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery term i-
nal on the s econd vehicle.
Connect the clamp at the other e nd of the negative cable to a
solid, stationary, unpainted metallic point away from the 12-vo lt
battery and any movin g parts, as shown in the illustration.
Start the engine of the second v ehicle. Increase the engine speed
slightly and maintain at that lev el for approximately 5 minutes to
recharge the 12-volt battery of your vehicle.
Maintain the engine speed of the second vehicle and start the
hybrid system of your vehicle by turning the power switch to ON
mode.
Make sure the “READY” indicator comes on. If the indicator ligh t
does not come on, contac t your Toyota dealer.3
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6527-2. Steps to take in an emergency
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Once the hybrid system has started, remove the jumper cables in
the exact reverse order from which they were connected.
To install the engine cover, conduct the removal procedure in
reverse. After installing, check that the fixed pins are inserted
securely.
Once the hybrid system starts, have the vehicle inspected at yo ur
Toyota dealer as soon as possible.
■ When opening the cover of the positive (+) battery terminal
P. 525
■ Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■ To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid s ystem is off.
● Turn off any unnecessary electrical components when the vehicle is running
at a low speed for an extended period, such as in heavy traffic .
■ When the 12-volt battery is removed or discharged
● Information stored in the ECU is cleared. When the 12-volt batt ery is
depleted, have the vehicle inspected at your Toyota dealer.
● Some systems may require initialization. ( P. 701)
■ When removing the 12-vo lt battery terminals
When the 12-volt battery terminals are removed, the information stored in the
ECU is cleared. Before removing the 12-volt battery terminals, contact your
Toyota dealer.
■ Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gr adually even when
the vehicle is not in use, due to natural discharge and the dra ining effects of
certain electrical appliances. If the vehicle is left for a lon g time, the 12-volt
battery may discharge, and the hybrid system may be unable to s tart. (The
12-volt battery recharges automatically while the hybrid system is operating.)
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6537-2. Steps to take in an emergency
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When trouble arises
■When recharging or replacing the 12-volt battery
●In some cases, it may not be possible to unlock the doors using the smart
key system when the 12-volt battery is discharged. Use the wire less remote
control or the mechanical key to lock or unlock the doors.
● The hybrid system may not start on the first attempt after the 12-volt battery
has recharged but will start normally after the second attempt. This is not a
malfunction.
● The power switch mode is memorized by the vehicle. When the 12- volt bat-
tery is reconnected, the system will return to the mode it was in before the
12-volt battery was discharged. Before disconnecting the 12-volt battery,
turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt bat-
tery discharged, be especially careful when reconnecting the 12 -volt battery.
● If the 12-volt battery discharges while the shift position is in P, it may not be
possible to shift the shift position to other positions. In thi s case, the vehicle
cannot be towed without lifting both front wheels because the f ront wheels
will be locked. ( P. 584)
■ When replacing the 12-volt battery
●Use a 12-volt battery that conforms to European regulations.
● Use a 12-volt battery that the case size is same as the previou s one (LN1),
20 hour rate capacity (20HR) is equivalent (45Ah) or greater, and perfor-
mance rating (CCA) is equivalent (295A) or greater.
• If the sizes differ, the 12-volt battery cannot be properly se cured.
• If the 20 hour rate capacity is low, even if the time period w here the vehi-
cle is not used is a short time, the 12-volt battery may discharge and the
hybrid system may not be able to start.
● For details, consult your Toyota dealer.

6547-2. Steps to take in an emergency
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WARNING
■When removing the 12-vo lt battery terminals
Always remove the negative (-) terminal first. If the positive (+) terminal con-
tacts any metal in the surrounding area when the positive (+) terminal is
removed, a spark may occur, leading to a fire in addition to el ectrical shocks
and death or serious injury.
■ Avoiding 12-volt batte ry fires or explosions
Observe the following precautions to prevent accidentally ignit ing the flam-
mable gas that may be emitted from the 12-volt battery:
● Make sure each jumper cable is connected to the correct terminal and that
it is not unintentionally in contact with any other than the in tended terminal.
● Do not allow the other end of the jumper cable connected to the “+” termi-
nal to come into contact with any other parts or metal surfaces in the area,
such as brackets or unpainted metal.
● Do not allow the + and - clamps of the jumper cables to come in to contact
with each other.
● Do not smoke, use matches, cigarette lighters or allow open fla me near
the 12-volt battery.
■ 12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic ele ctrolyte,
while related parts contain lead and lead compounds. Observe th e following
precautions when handling the 12-volt battery:
● When working with the 12-volt battery, always wear safety glass es and
take care not to allow any battery fluids (acid) to come into c ontact with
skin, clothing or the vehicle body.
● Do not lean over the 12-volt battery.
● In the event that battery fluid comes into contact with the skin or eyes,
immediately wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medica l attention
can be received.
● Always wash your hands after handling the 12-volt battery suppo rt, termi-
nals, and other battery-related parts.
● Do not allow children near the 12-volt battery.

6557-2. Steps to take in an emergency
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When trouble arises
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not beco me entan-
gled in the cooling fans, etc.

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7-2. Steps to take in an emergency
If your vehicle overheats
■If the high coolant temperature warning light comes on or
flashesStop the vehicle in a safe place and turn off the air conditioning
system, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect t he
hoses and radiator core (ra diator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light ( P. 594) comes on
or flashes, or a loss of hybrid system power is experienced. (F or
example, the vehicle s peed does not increase.)
● “Hybrid System Overheated” is shown on the multi-information
display.
● Steam comes out from under the hood.
Correction procedures
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