Page 455 of 552
4558-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52E68U)
*1: Refer to the separate “Scheduled Maintenance Guide” or “Owner’s ManualSupplement” for the maintenance interval applicable to your vehicle.
*2: For the EV drive mode operating conditions:P. 194
Carrying out the corresponding action turns the message off.
Indicates that the shift lever is shifted while the
accelerator pedal is being depressed A buzzer also sounds.
Release the accelerator pedal.
Other displayed message
Displayed messageDetails/Actions
Maintenance of the hybrid system (traction bat-
tery) cooling component is required
The filter may be clogged, the air vent may be
blocked or there may be a gap in the duct.
Have maintenance performed on the hybrid
system (traction battery) cooling component
at your Toyota dealer.
Warning messageDetails/Actions
(Flashes)
Page 457 of 552
4578-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52E68U)
Once
Contin-uous
(For 5 sec-
onds)
An attempt was made to lock
the doors using the entry func-
tion after the electronic key was
carried outside the vehicle with-
out turning off the “POWER”
switch.
Turn the “POWER” switch
off and lock the doors
again.
9 times
An attempt was made to start
the hybrid system without the
electronic key being present, or
the electronic key was not func-
tioning normally.
An attempt was made to drive
when the regular key was not
inside the vehicle.
Confirm that the elec-
tronic key is inside the
vehicle.
Contin-
uous
The driver’s door was opened
while a shift lever position other
than P was selected without
turning off the “POWER”
switch.
Shift the shift lever to P.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Displayed alternately)
(Flashes)
(Flashes)
(Flashes)
Page 458 of 552

4588-2. Steps to take in an emergency
PRIUS c_U (OM52E68U)
Contin-uousContin-uous
The electronic key was carried
outside the vehicle and the
driver’s door was opened and
closed while a shift lever posi-
tion other than P was selected
without turning off the
“POWER” switch.
Shift the shift lever to P.
Bring the electronic key
back into the vehicle.
Contin-
uous
(5 sec-
onds)
An attempt was made to lock
the doors using the smart key
system while the electronic key
was still inside the vehicle.
Retrieve the electronic key
from the vehicle and lock
the doors again.
Once
Contin-
uous
(5 sec- onds)
An attempt was made to lock
either front door by opening a
door and putting the inside door
lock button into the lock posi-
tion, and then closing the door
while pulling on the outside
door handle with the electronic
key still inside the vehicle.
Retrieve the electronic key
from the vehicle and lock
the doors again.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Displayed alternately)
(Flashes)
(Flashes)
(Flashes)
Page 477 of 552

4778-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52E68U)
Firmly depress the brake pedal and check that is displayed
on the multi-information display.
Press the “POWER” switch.
In the event that the “POWER” switch still cannot be operated, contact
your Toyota dealer.
■ Stopping the hybrid system
Shift the shift lever 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 recommended that the
electronic key battery be replaced imm ediately when the battery is depleted.
( P. 413)
■ Changing “POWER” switch modes
Release the brake pedal and press the “POWER” switch in above.
The hybrid system does not start and modes will be changed each time the
switch is pressed. ( P. 187)
■ If the doors cannot be locked or unlocked by the smart key system
Lock and unlock the doors by the mechanical key or wireless remote control.
■ 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. 514)
● Check if battery-saving mode is set. If it is set, cancel the function.
(P. 139)
3
4
3
Page 483 of 552

4838-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52E68U)
● ( P. 450) is shown on the multi-information display.
● The hybrid system overheat warning message ( P. 453) is shown
on the multi-information display.
● Steam comes out from under the hood.
■If is shown on the multi-information display
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 radia-
tor core (radiator) for any
leaks. Radiator
Cooling fan
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.Reservoir
“FULL” line
“LOW” line
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
4
1
2
3
Page 485 of 552
4858-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52E68U)■
If the hybrid system overheat warning message is shown on
the multi-information 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 fan
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The coolant level is satisfac-
tory if it is between the “F”
and “L” lines on the reservoir.Reservoir
“F” line
“L” line
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check for the multi-information dis-
play.
If the message does not disappear:
Stop the hybrid system and contact your Toyota dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Toyota dealer.
1
2
3
1
2
4
1
2
3
5
6
Page 486 of 552

4868-2. Steps to take in an emergency
PRIUS c_U (OM52E68U)
WARNING
■To prevent an accident or injury when inspecting under the hood of
your vehicle
●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, caus-
ing serious injuries such as burns.
● After the hybrid system has been turned off, check that on the
multi-information display and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automati-
cally start, or the cooling fan 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 radiator cap whil e the hybrid system and radiator are
hot.
Serious injuries, such as burns, may result from hot coolant and steam
released under pressure.
NOTICE
■ When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power
control unit coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid sys-
tem 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.
Page 539 of 552
539What to do if... (Troubleshooting)
PRIUS c_U (OM52E68U)
●The auto power off function will be operated if the vehicle is left in ACCES-
SORY or ON mode (the hybrid system is not running) for a period of time.
(P. 188)
●The seat belt reminder light is flashing
Are the driver and the front passenger wearing the seat belts? ( P. 443)
●The brake system warning light is on
Is the parking brake released? (P. 200)
Depending on the situation, other types of warning buzzer may also sound.
( P. 441, 449)
●Is the electronic key left inside the vehicle?
Vehicles with a multi-information display: Check the message on the multi-
information display. ( P. 449)
The “POWER” switch is turned off automatically
(vehicles with a smart key system)
A warning buzzer sounds during driving
A warning buzzer sounds when leaving the vehicle
(vehicles with a smart key system)