2021 TOYOTA PRIUS key battery

PRIUS_OM_OM47E09U_(U)
2474-2. Driving procedures
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Driving
Modes can be changed by pressing the power switch with the brake
pedal released. (The mode changes each time the switch is pressed.)
Off
The emergency flashers can be
used.
ACCESSORY mode
Some electrical components such
as the audio system can be used.
“Accessory” is displayed on the
main display.
ON mode
All electrical components can be
used.
“Ignition ON” is displayed on the
main display.
■ Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minut es or ON
mode (the hybrid system is not operating) for more than an hour with the shift
position in P, the power switch will automatically turn off. Ho wever, this func-
tion cannot entirely prevent the 12-volt battery discharge. Do not leave the
vehicle with the power switch in ACCESSORY or ON mode for long periods
of time when the hybrid system is not operating.
■ Sounds and vibrations sp ecific to a hybrid vehicle
P. 87
■ Electronic key battery depletion
P. 182
Changing power switch modes
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PRIUS_OM_OM47E09U_(U)
4-2. Driving procedures
■When the ambient temperature is low, such as during winter driv ing con-
ditions
● When starting the hybrid system, the flashing time of the “READY” indicator
may be long. Leave the vehicle as it is until the “READY” indic ator is steady
on, as steady means the vehicle is able to move.
● When the hybrid battery (traction battery) is extremely cold (b elow approxi-
mately -22°F [-30°C]) under the influence of the outside temper ature, it may
not be possible to start the hybrid system. In this case, try t o start the hybrid
system again after the temperature of the hybrid battery increa ses due to
the outside temperature increase etc.
■ Conditions affecting operation
P. 198
■ Note for the entry function
P. 199
■ If the hybrid system does not start
●The immobilizer system may not have been deactivated. ( P. 95)
Contact your Toyota dealer.
● If a message related to start-up is shown on the multi-informat ion display,
read the message and follow the instructions.
■ If the “READY” indicator does not come on
In the event that the “READY” indicator does not come on even a fter perform-
ing the proper procedures for starting the vehicle, contact you r Toyota dealer
immediately.
■ If the hybrid system is malfunctioning
P. 89
■ If the electronic key battery is depleted
P. 560
■ Operation of the power switch
●If the switch is not pressed shortly and firmly, the power switch mode may
not change or the hybrid system may not start.
● If attempting to restart the hybrid system immediately after tu rning the power
switch off, the hybrid system may not start in some cases. After turning the
power switch off, please wait a few seconds before restarting t he hybrid sys-
tem.

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PRIUS_OM_OM47E09U_(U)
5-2. Using the interior lights
Turns the switch to the door
position (door linked)
Operation is linked with the front
interior light main switch. When the
switch is off, the light does not illu-
minate.
Turns the light on
■Illuminated entry system
The lights automatically turn on/off according to power switch mode, the pres-
ence of the electronic key, whether the doors are locked/unlocked, and
whether the doors are opened/closed.
■ To prevent the 12-volt batte ry from being discharged
If the interior lights remain on when the power switch is turned off, the light
will go off automatically after 20 minutes.
■ Customization
Settings (e.g. the time elapsed before the lights turn off) can be changed.
(Customizable features: P. 690)
Rear interior light
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NOTICE
To prevent 12-volt battery discharge, do not leave the lights o n longer than
necessary when the hybrid system is off.

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PRIUS_OM_OM47E09U_(U)
6Maintenance and care
6-1. Maintenance and careCleaning and protecting the vehicle exterior .......... 496
Cleaning and protecting the vehicle interior ........... 502
6-2. Maintenance Maintenance requirements ................... 505
General maintenance........ 508
Emission inspection and maintenance (I/M)
programs......................... 511
6-3. Do-it-yourself maintenance
Do-it-yourself service precautions ..................... 512
Hood ................................. 515
Positioning a floor jack ...... 517
Engine compartment ......... 518
Tires .................................. 532
Tire inflation pressure ....... 542
Wheels .............................. 545
Air conditioning filter.......... 548
Cleaning the hybrid battery (traction battery) air intake
vent and filter .................. 551
Wiper insert replacement .................... 556
Electronic key battery........ 560
Checking and replacing fuses ............................... 563
Headlight aim .................... 566
Light bulbs......................... 568

PRIUS_OM_OM47E09U_(U)
4976-1. Maintenance and care
6
Maintenance and care
■Note for a smart key system
If the door handle becomes wet while the electronic key is within the effective
range, the door may lock and unlock repeatedly. In that case, f ollow the fol-
lowing correction procedures to wash the vehicle:
● Place the key in a position 6 ft. (2 m) or more separate from t he vehicle
while the vehicle is being washed. (Take care to ensure that th e key is not
stolen.)
● Set the electronic key to battery-saving mode to disable the sm art key sys-
tem. ( P. 198)
■ Wheels and wheel ornaments
●Remove any dirt immediately by using a neutral detergent.
● Wash detergent off with water immediately after use.
● To protect the paint from damage, make sure to observe the following pre-
cautions.
• Do not use acidic, alkaline or abrasive detergent
• Do not use hard brushes
• Do not use detergent on the wheels when they are hot, such as after driv-
ing or parking in hot weather
■ Bumpers
Do not scrub with abrasive cleaners.
■ Front side windows water-repellent coating (if equipped)
The following precautions can extend the effectiveness of the water-repellent
coating.
●Remove any dirt, etc. from the front side windows regularly.
● Do not allow dirt and dust to accumulate on the windows for a long period.
Clean the windows with a soft, damp cloth as soon as possible.
● Do not use wax or glass cleaners that contain abrasives when cleaning the
windows.
● Do not use any metallic objects to remove condensation build up.
■ Plated portions
If dirt cannot be removed, clean the parts as follows:
●Use a soft cloth dampened with an approximately 5% solution of neutral
detergent and water to clean the dirt off.
● Wipe the surface with a dry, soft cloth to remove any remaining moisture.
● To remove oily deposits, use alcohol wet wipes or a similar pro duct.

PRIUS_OM_OM47E09U_(U)
5256-3. Do-it-yourself maintenance
6
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, observe the following precautio ns 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 connectin g and dis-
connecting the charger cables to the 12-volt battery.
■ After recharging/reconnecting the 12-volt battery
●Unlocking the doors using the smart key system may not be possi ble 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 do ors.
● 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-vol t battery is
reconnected, the vehicle will return the power switch mode to t he status it
was in before the 12-volt battery was disconnected. Make sure t o turn off
the power before disconnect the 12-volt battery. Take extra car e when con-
necting the 12-volt battery if the power switch mode prior to d ischarge is
unknown.
If the system will not start even after multiple attempts at al l methods above,
contact your Toyota dealer. While pushing the portion shown in the
illustration from both sides, lift the end of
the cover up.

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PRIUS_OM_OM47E09U_(U)
6-3. Do-it-yourself maintenance
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 n ew one if it is depleted.
You will need the following items:
Replacing the battery
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PRIUS_OM_OM47E09U_(U)
5616-3. Do-it-yourself maintenance
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 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 the local laws.
■ If the electronic key battery is depleted
The following symptoms may occur:
●The smart key system and wireless remote control will not funct ion properly.
● The operational range will be reduced.
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