Page 430 of 596

4307-3. Do-it-yourself maintenance
PRIUS c_U (OM52J11U)■
When disconnecting the 12- volt battery terminals
Always disconnect the negative (-) terminal first.
■ After recharging/reconnecting the 12-vo lt battery (vehicles with a smart
key system)
● Unlocking the doors using the smart key system may not be possible 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 doors.
● Start the hybrid system with the “POWER” switch in ACCESSORY mode.
The hybrid system may not start with the “POWER” switch turned off. How-
ever, the hybrid system will operat e normally from the second attempt.
● The “POWER” switch mode is recorded by the vehicle. If the 12-volt battery
is reconnected, the vehicle will return the “POWER” switch mode to the sta-
tus it was in before the 12-volt battery was disconnected. Make sure to turn
off the power before disconnect the 12-volt battery. Take extra care when
connecting the 12-volt battery if the “POWER” switch mode prior to dis-
charge is unknown.
If the system will not start even after multiple attempts, contact your Toyota
dealer.
WARNING
■ Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid 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 with 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 battery.
● 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 charge the 12-
volt battery in a garage or closed room where there is insufficient ventila-
tion.
Page 448 of 596
4487-3. Do-it-yourself maintenance
PRIUS c_U (OM52J11U)
●Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), or
CR2032 (vehicles with a smart key system)
Remove the cover.
To prevent damage to the key,
cover the tip of the screwdriver with
a rag.
To prevent the buttons from being
disassembled, face the button sur-
face downward.
Remove the module.
Open the case cover using a
coin protected with tape etc.
and remove the depleted bat-
tery using a small flathead
screwdriver.
Insert a new battery with the “+”
terminal facing up.
Wireless remote control/electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery (vehicl es without a smart key system)
1
2
3
Page 449 of 596
4497-3. Do-it-yourself maintenance
7
Maintenance and care
PRIUS c_U (OM52J11U)
Take out the mechanical key.
Remove the cover.
To prevent damage to the key,
cover the tip of the screwdriver with
a rag.
Remove the depleted battery
using a small flathead screw-
driver.
When removing the cover, the
electronic module may stick to the
cover and the battery may not be
visible. In this case, remove the
electronic module in order to
remove the battery.
Insert a new battery with the “+”
terminal facing up.
Replacing the battery (vehicles with a smart key system)
1
2
3
Page 450 of 596

4507-3. Do-it-yourself maintenance
PRIUS c_U (OM52J11U)
■Use a CR2016 (vehicles without a sm art key system) or CR2032 (vehicles
with a smart key system) lithium battery
● Batteries can be purchased at your Toyota dealer, local electrical appliance
shops or camera stores.
● Replace only with the same or equivalent type recommended by the manu-
facturer.
● Dispose of used batteries according to local laws.
■ If the key battery is depleted
The following symptoms may occur:
●The smart key system (if equipped) and wireless remote control will not
function properly.
● The operational range will be reduced.
WARNING
■Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking.
Keep away from children. Failure to do so could result in death or serious
injury.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents:
● Always work with dry hands.
Moisture may cause the battery to rust.
● Do not touch or move any other component inside the remote control.
● Do not bend either of the battery terminals.
Page 465 of 596
465
8When trouble arises
PRIUS c_U (OM52J11U)8-1. Essential information
Emergency flashers .......... 466
If your vehicle has to be stopped in an
emergency ...................... 467
8-2. Steps to take in an emergency
If your vehicle needs to be towed ..................... 469
If you think something is wrong .......................... 476
If a warning light turns on or a warning buzzer
sounds ............................ 477
If a warning message is displayed ..................... 486
If you have a flat tire.......... 501
If the hybrid system will not start ..................... 514
If the electronic key does not operate
properly ........................... 516
If the vehicle 12-volt battery is discharged ....... 518
If your vehicle overheats ........................ 524
If the vehicle becomes stuck ............................... 528
Page 492 of 596

4928-2. Steps to take in an emergency
PRIUS c_U (OM52J11U)Indicates that the driver’s door was opened with
the shift position in N, D or B
A buzzer also sounds.
→ Shift the shift lever to P.
Indicates that the accelerator pedal is depressed
while the shift position is in N A buzzer also sounds.
→ Release the accelerator pedal and shift the
shift lever to D, B or R.
Indicates that the engine switch is turned to the
“ACC” or “LOCK” position (vehicles without a
smart key system) or the “POWER” switch is
turned to ACCESSORY mode or turned off (vehi-
cles with a smart key system) and the driver’s
door is opened while the lights are turned on A buzzer also sounds.
→ Turn the lights off.
Indicates that the EV drive mode is not avail-
able
*2
The reason the EV drive mode is not available
(the vehicle is idling, battery charge is low,
speed is higher than the EV drive mode operat-
ing speed range, accelerator pedal is
depressed too much) may be displayed.
A buzzer also sounds.
→ Use the EV drive mode when it becomes
available.
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
Page 495 of 596
4958-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52J11U)
Carrying out the corresponding action turns the message off.
After taking the specified steps to correct the suspected problem,
check that the warning message and light go off.
Other displayed message
Displayed messageDetails/Actions
Maintenance of the hybrid battery (traction battery)
cooling component is required The filter may be clogged, the air intake vent
may be blocked or there may be a gap in the
duct.
→ Have maintenance performed on the hybrid
battery (traction batter y) cooling component
at your Toyota dealer.
Have the malfunction repaired immediately. (vehicles with a
smart key system)
Interior
buzzerExterior buzzerWarning messageDetails/Actions
Once ⎯ The electronic key is not
detected when an attempt is
made to start the hybrid sys-
tem.
→
Start the hybrid system
with the electronic key
present.
(Flashes)
Page 499 of 596
4998-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52J11U)
⎯⎯
Power was turned off due to the
automatic power off function.
→Next time when starting
the hybrid system,
increase the engine speed
slightly and maintain that
level for approximately 5
minutes to recharge the
12-volt-battery.
Once⎯
The electronic key has a low
battery.
→Replace the electronic key
battery. ( →P. 448)
Once⎯
The driver's door was opened
and closed with the “POWER”
switch turned off and then the
“POWER” switch was put in
ACCESSORY mode twice with-
out the hybrid system being
started.
→Press the “POWER”
switch while depressing
the brake pedal.
During a hybrid system starting
procedure in the event that the
electronic key was not function-
ing properly
(→P. 516), the “POWER” switch
was touched with the electronic
key.
→ Press the “POWER”
switch within 10 seconds
of the buzzer sounding.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes)