2020 TOYOTA PRIUS C key battery

4517-3. Do-it-yourself maintenance
7
Maintenance and care
PRIUS c_U
●Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), o r
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 batter y
Replace the battery with a n ew one if it is depleted.
You will need the following items:
Replacing the battery (vehicles without a smart key system)
1
2
3

4527-3. Do-it-yourself maintenance
PRIUS c_U
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

4537-3. Do-it-yourself maintenance
7
Maintenance and care
PRIUS c_U
■Use a CR2016 (vehicles without a smart key system) or CR2032 (v ehicles
with a smart key system) lithium battery
● Batteries can be purchased at your Toyota dealer, local electri cal 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 a nd 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 cont rol.
● Do not bend either of the battery terminals.

467
8When trouble arises
PRIUS c_U8-1. Essential information
Emergency flashers .......... 468
If your vehicle has to be stopped in
an emergency ................. 469
If the vehicle is trapped in rising water.................. 471
8-2. Steps to take in an emergency
If your vehicle needs to be towed ..................... 472
If you think something is wrong .......................... 479
If a warning light turns on or a warning buzzer
sounds ............................ 480
If a warning message is displayed ..................... 488
If you have a flat tire.......... 505
If the hybrid system will not start ..................... 518
If the electronic key does not operate properly ........ 520
If the vehicle 12-volt battery is discharged ....... 522
If your vehicle overheats ........................ 529
If the vehicle becomes stuck ................ 533

4948-2. Steps to take in an emergency
PRIUS c_UIndicates that the hybrid battery (traction battery)
power has dropped because a long period of time
has elapsed after shifting the shift lever to N
A buzzer also sounds.
 Shift the shift lever to P and restart the
hybrid system when starting the vehicle.
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 power 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 (vehicles
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.
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Flashes)

4998-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
Carrying out the corresponding action turns the message off.
After taking the specified steps to correct the suspected probl em,
check that the warning m essage 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.
 If the air intake vent is dirty, refer to P. 404
for cleaning the air intake vent.
 If the message is being displayed and the air
intake vent is not dirty, have the vehicle
inspected 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)

5038-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U

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. 451)
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. 520), 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)

5188-2. Steps to take in an emergency
PRIUS c_U
One of the following may be the cause of the problem:
● Vehicles with a smart key system: The electronic key may not be
functioning properly. ( P. 520)
● There may not be sufficient f uel in the vehicle’s tank.
Refuel the vehicle. ( P. 221)
● Vehicles with immobilizer syste m: There may be a malfunction in
the immobilizer system. ( P. 8 8 )
● There may be a malfunction i n the steering lock system.
● Vehicles with a smart key system : The hybrid system may be mal-
functioning due to an electrical problem such as an open circui t or a
blown fuse. However, depending on the type of malfunction, an
interim measure is available to start the hybrid system. (P. 519)
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( P. 522)
● The 12-volt battery terminal conn ections may be loose or corroded.
(  P. 431)
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on
the situation. Check the followi ng and perform the appropriate
procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 188, 192)
The interior lights and headlights are dim, or the horn does no t
sound or sounds at a low volume.