Toyota Prius (2022 year). Manual in english - page 40

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 your
Toyota dealer as soon as possible.

■

When opening the cover of the positive (+) battery terminal

P. 521

■

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 system 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 battery is
depleted, have the vehicle inspected at your Toyota dealer.

●

Some systems may require initialization. (



P. 697)

■

When removing the 12-volt 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 gradually even when
the vehicle is not in use, due to natural discharge and the draining effects of
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the hybrid system may be unable to start. (The
12-volt battery recharges automatically while the hybrid system is operating.)

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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 wireless 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 this case, the vehicle
cannot be towed without lifting both front wheels because the front wheels
will be locked. (

P. 580)

■

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 previous 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 secured.
• If the 20 hour rate capacity is low, even if the time period where 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.

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WARNING

■

When removing the 12-volt 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 electrical shocks
and death or serious injury.

■

Avoiding 12-volt battery fires or explosions

Observe the following precautions to prevent accidentally igniting 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 intended 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 into contact
with each other.

●

Do not smoke, use matches, cigarette lighters or allow open flame near
the 12-volt battery.

■

12-volt battery precautions

The 12-volt battery contains poisonous and corrosive acidic electrolyte,
while related parts contain lead and lead compounds. Observe the following
precautions when handling the 12-volt battery:

●

When working with the 12-volt battery, always wear safety glasses and
take care not to allow any battery fluids (acid) to come into contact 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 medical attention
can be received.

●

Always wash your hands after handling the 12-volt battery support, termi-
nals, and other battery-related parts.

●

Do not allow children near the 12-volt battery.

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NOTICE

■

When handling jumper cables

When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fans, etc.

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If your vehicle overheats

■

If the high coolant temperature warning light comes on or
flashes

Stop 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 the
hoses and radiator core (radiator) 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. 590) comes on

or flashes, or a loss of hybrid system power is experienced. (For
example, the vehicle speed 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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The coolant level is satisfactory if it is between the “MAX” and
“MIN” lines on the reservoir.

Reservoir
“MAX” line
“MIN” line

Add coolant if necessary.

Water can be used in an emer-
gency if coolant is unavailable.

Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fans operate and to check for
coolant leaks from the radiator or hoses.

The fans operate when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fans are operating by checking
the fan sound and air flow. If it is difficult to check these, turn the air con-
ditioning system on and off repeatedly. (The fans may not operate in
freezing temperatures.)

If the fans are not operating:
Stop the hybrid system immediately and contact your Toyota
dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Toyota dealer.

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■

If “Hybrid System Overheated” is shown on the multi-informa-
tion display

Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, inspect the hoses and
radiator core (radiator) for any leaks.

Radiator
Cooling fans

If a large amount of coolant
leaks, immediately contact
your Toyota dealer.

The coolant level is satisfactory if it is between the “FULL” and
“LOW” lines on the reservoir.

Reservoir
“FULL” line
“LOW” line

Add coolant if necessary.

Water can be used in an emer-
gency if coolant is unavailable.
If water was added in an emer-
gency, have the vehicle inspected
at your Toyota dealer as soon as
possible.

1
2

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3

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After stopping the hybrid system and waiting for 5 minutes or
more, start the hybrid system again and check if “Hybrid System
Overheated” is shown on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Toyota dealer.
If the message is not displayed:
The hybrid system temperature has dropped and the vehicle may
be driven normally.

However, if the message appears again frequently, contact your Toyota
dealer.

WARNING

■

To prevent an accident or injury when inspecting under the hood of
your vehicle

Observe the following precautions.
Failure to do so may result in serious injury such as burns.

●

If steam is seen coming from under the hood, do not open the hood until
the steam has subsided. The engine compartment may be very hot.

●

After the hybrid system has been turned off, check that the “Accessory”,
“Ignition ON” or mileage display (



P. 116) on the main display and the

“READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automati-
cally start, or the cooling fans may suddenly operate even if the gasoline
engine stops. Do not touch or approach rotating parts such as the fan,
which may lead to fingers or clothing (especially a tie, a scarf or a muffler)
getting caught, resulting in serious injury.

●

Do not loosen the coolant reservoir caps while the hybrid system and radi-
ator are hot.
High temperature steam or coolant could spray out.

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NOTICE

■

When adding engine/power control unit coolant

Add coolant slowly after the hybrid system has cooled down sufficiently.
Adding cool coolant to a hot hybrid system too quickly can cause damage to
the hybrid system.

■

To prevent damage to the cooling system

Observe the following precautions:

●

Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).

●

Do not use any coolant additive.

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If the vehicle becomes stuck

Set the parking brake and shift the shift position to P. Stop the
hybrid system.
Remove the mud, snow or sand from around the front wheels.
Place wood, stones or some other material under the front wheels
to help provide traction.
Restart the hybrid system.
Shift the shift position to D or R and release the parking brake.
Then, while exercising caution, depress the accelerator pedal.

■

When it is difficult to free the vehicle

Carry out the following procedures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:

Press

to turn off TRAC. (

P. 417)

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