2023 TOYOTA PRIUS key battery

5236-3. Do-it-yourself maintenance
PRIUS_OM_OM47F32E_(EE)
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Maintenance and care
■When opening the cover of the positive (+) battery terminal
■ Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flam-
mable and explosive. Therefore, obser ve the following precautions before
recharging:
● If recharging with the 12-volt battery installed on the vehicle, be sure to dis-
connect the ground cable.
● Make sure the power switch on the charger is off when connecting and dis-
connecting the charger cables to the 12-volt battery.
■ After recharging/reconnecting the 12-volt battery
● Unlocking the doors using the smart entry & start system may not be possi-
ble immediately after reconnecting the 12-volt battery. If this happens, use
the wireless 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. However, the
hybrid system will operate 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 status it
was in before the 12-volt battery was disconnected. Make sure to turn off
the power switch 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 at all methods above,
contact any authorized Toyota retailer or Toyota authorized repairer, or any
reliable repairer.
While pushing the portion shown in the
illustration from both sides, lift the end of
the cover up.

5546-3. Do-it-yourself maintenance
PRIUS_OM_OM47F32E_(EE)
Electronic key batter y
●Flathead screwdriver
●Lithium battery CR2032
Release the lock and take out
the mechanical key.
Remove the cover.
Use a screwdriver of an appropri-
ate size. Forcedly prying may
cause the cover damaged.
To prevent damage to the key,
cover the tip of the screwdriver with
a rag.
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
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5556-3. Do-it-yourself maintenance
PRIUS_OM_OM47F32E_(EE)
6
Maintenance and care
Remove the depleted battery.
When removing the cover, if the
battery cannot be seen due to the
electronic key module attaching to
the upper cover, remove the elec-
tronic key module from the cover
so that the battery is visible as
shown in the illustration.
When removing the battery, use a
screwdriver of an appropriate size.
Insert a new battery with the “+” terminal facing up.
When installing, reverse the steps listed.
■Use a CR2032 lithium battery
●Batteries can be purchased at any authorized Toyota retailer or Toyota
authorized repairer, or any reliable repairer, 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 the local laws.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart entry & start system and wireless remote control will not function
properly.
●The operational range will be reduced.
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5566-3. Do-it-yourself maintenance
PRIUS_OM_OM47F32E_(EE)
WARNING
■Battery precautions
Observe the following precautions.
Failure to do so may result in death or serious injury.
● Do not swallow the battery. Doing so may cause chemical burns.
● A coin battery or button battery is used in the electronic key. If a battery is
swallowed, it may cause severe chemical burns in as little as 2 hours and
may result in death or serious injury.
● Keep away new and removed batteries from children.
● If the cover cannot be firmly closed, stop using the electronic key and stow
the key in the place where children cannot reach, and then contact any
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer as soon as possible.
● If you accidentally swallow a battery or put a battery into a part of your
body, get emergency medical attention immediately.
■ To prevent battery explosion or leakage of flammable liquid or gas
● Replace the battery with a new battery of the same type. If a wrong type of
battery is used, it may explode.
● Do not expose batteries to extremely low pressure due to high altitude or
extremely high temperatures.
● Do not burn, break or cut a battery.
■ Certification for the smart entry & start system
CAUTION
RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT
TYPE.
DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS
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.

567
7When trouble arises
PRIUS_OM_OM47F32E_(EE)
7-1. Essential information
Emergency flashers ........... 568
If your vehicle has to
be stopped in an
emergency ....................... 569
If the vehicle is submerged
or water on the road is
rising ................................ 570
7-2. Steps to take in an
emergency
If your vehicle needs
to be towed ...................... 572
If you think something is
wrong ............................... 579
If a warning light turns on
or a warning buzzer
sounds ............................. 580
If a warning message is
displayed ......................... 589
If you have a flat tire
(vehicles without
spare tire) ........................ 598
If you have a flat tire
(vehicles with
spare tire) ........................ 618
If the hybrid system will
not start............................ 634
If the electronic key does
not operate properly ........ 636
If the 12-volt battery is
discharged ....................... 639
If your vehicle
overheats ......................... 645
If the vehicle becomes
stuck ................................ 650

6347-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
If the hybrid system will not star t
One of the following may be the cause of the problem:
● The electronic key may not be functioning properly.* (P. 636)
● There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ( P. 8 6 )
● There may be a malfunction in the immobilizer system.* (P. 9 1 )
● There may be a malfunction in the shift control system.*
( P. 247, 597)
● The hybrid system may be malfunctioning due to an electrical prob-
lem such as electronic key battery depletion or a blown fuse. How-
ever, depending on the type of malfunction, an interim measure is
available to start the hybrid system. ( P. 635)
*: It may not be possible to shift the shift position other than P.
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. (P. 639)
● The 12-volt battery terminal connections may be loose or corroded.
( P. 521)
Reasons for the hybrid system not starting vary depending on
the situation. Check the following and perform the appropriate
procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 244)
The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.

6367-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
If the electronic key does not operate
properly
Use the mechanical key ( P. 173) in order to perform the following
operations:
Locks all the doors
Closes the windows and moon
roof *1 (turn and hold)*2
Unlocks all the doors
Opens the windows and moon
roof *1 (turn and hold)*2
*1: If equipped
*2: This setting must be customized at
any authorized Toyota retailer or
Toyota authorized repairer, or any
reliable repairer. ( P. 670)
If communication between the electronic key and vehicle is inter-
rupted ( P. 190) or the electronic key cannot be used because the
battery is depleted, the smart entry & start system and wireless
remote control cannot be used. In such cases, the doors can be
opened and the hybrid system can be started by following the pro-
cedure below.
Locking and unlocking the doors
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6387-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
■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 recommended that the
electronic key battery be replaced imm ediately when the battery is depleted.
( P. 554)
■ Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set,
the alarm may be triggered. ( P. 9 3 )
■ Changing power switch modes
Release the brake pedal and press the power switch in step above. The
hybrid system does not start and modes will be changed each time the switch
is pressed. ( P. 246)
■ When the electronic key does not work properly
● Make sure that the smart entry & start system has not been deactivated in
the customization setting. If it is off, turn the function on.
(Customizable features: P. 670)
● Check if battery-saving mode is set. If it is set, cancel the function.
( P. 189)
WARNING
■When using the mechanical key and operating the power windows or
moon roof (if equipped)
Operate the power window or moon roof after checking to make sure 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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