2023 TOYOTA COROLLA HYBRID battery

3156-3. Do-it-yourself maintenance
6
Maintenance and care
Light bulbs
( P.356)
• Bulb with same
number and wattage
rating as original
• Flathead screw- driver
• Wrench
Radiator
and con-
denser
(  P.321)

Tire infla-
tion pres-
sure
( P.342)• Tire pressure gauge
• Compressed air
source
Washer
fluid
( P.324)
• Water or washer
fluid containing anti-
freeze (for winter
use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains
many mechanisms and fluids that
may move suddenly, become hot,
or become electrically energized.
To avoid death or serious injury,
observe the following precautions.
■When working on the engine
compartment
●Make sure that the “ACCES-
SORY” or “IGNITION ON” on
the multi-inform ation display
and the “READY” indicator are
both off.
●Keep hands, clothing and tools
away from the moving fans.
ItemsParts and tools●Be careful not to touch the
engine, power control unit, radi-
ator, exhaust manifold, etc. right
after driving as they may be hot.
Oil and other fluids may also be
hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the engine compart-
ment.
●Do not smoke, cause sparks or
expose an open flame to fuel or
the 12-volt battery. Fuel and
12-volt battery fumes are flam-
mable.
●Be extremely cautious when
working on the 12-volt battery. It
contains poisonous and corro-
sive sulfuric acid.
■When working near the elec-
tric cooling fans or radiator
grille
Be sure the power switch is OFF.
With the power switch in ON, the
electric cooling fans may auto-
matically start to r un if the air con-
ditioning is on an d/or the coolant
temperature is high. ( P.321)
■Safety glasses
Wear safety glasses to prevent
flying or falling material, fluid
spray, etc. from getting in your
eyes.
NOTICE
■If you remove the air cleaner
filter
Driving with the air cleaner filter
removed may cause excessive
engine wear due to dirt in the air.

3186-3. Do-it-yourself maintenance
Washer fluid tank ( P.324)
Engine coolant reservoir ( P.320)
Fuse boxes ( P.354)
Engine oil level dipstick ( P.319)
Engine oil filler cap ( P.319)
Power control unit coolant reservoir ( P.320)
Brake fluid reservoir ( P.322)
12-volt battery ( P.323)
Radiator ( P.321)
Condenser ( P.321)
Electric cooling fans
With the engine at operating temperature and turned off,
check the oil level on the dip-
stick.
Engine compar tment
Components
Checking and adding the
engine oil

3236-3. Do-it-yourself maintenance
6
Maintenance and care
Check the 12-volt battery as fol-
lows.
■12-volt battery exterior
Make sure that the 12-volt bat-
tery terminals are not corroded
and that there are no loose con-
nections, cracks, or loose
clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the 12-volt bat-
tery produces hydrogen gas which
is flammable and explosive. There-
fore, observe the following precau-
tions before recharging:
●If recharging with the 12-volt bat-
tery installed on the vehicle, be
sure to disconnect the ground
cable.
●Make sure the charger is off when
connecting and disconnecting the
charger cables to the 12-volt bat-
tery.
■After recharging/reconnecting
the 12-volt battery (vehicles
with a smart key system)
●Unlocking the doors using the
smart key system may not be pos-
sible immediately after reconnect-
ing 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 ACC. The hybrid
system may not start with the
power switch turned off. However,
the hybrid system will operate nor-
mally 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 1 2-volt battery was dis-
connected. Make sure to turn off
the power before disconnecting
the 12-volt battery. Take extra
care when connecting the 12-volt
battery if the power switch mode
prior to discharge is unknown.
If the system will not start even after
multiple attempts, contact your Toy-
ota dealer.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level
to go down slightly as the brake
pads wear out or when the fluid
level in the accumulator is high.
If the reservoir needs frequent
refilling, there may be a serious
problem.
12-volt battery
WARNING
■Chemicals in the 12-volt bat-
tery
The 12-volt battery contains poi-
sonous and corrosive sulfuric acid
and may produce hydrogen gas
which is flammable and explosive.
To reduce the risk of death or seri-
ous injury, take the following pre-
cautions while working on or near
the 12-volt battery:

3246-3. Do-it-yourself maintenance
Add washer fluid in the following
situations:
A washer does not work.
 The warning message
appears on the multi-informa-
tion display.
WARNING
●Do not cause sparks by touch-
ing 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 electro-
lyte.
●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 insuf-
ficient ventilation.
■Emergency measures regard-
ing electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean
water for at least 15 minutes
and get immediate medical
attention. If possible, continue
to apply water with a sponge or
cloth while traveling to the near-
est medical facility.
●If electrolyte gets on your skin
Wash the affected area thor-
oughly. If you fee l pain or burn-
ing, get medical attention
immediately.
●If electrolyte gets on your
clothes
It can soak through clothing on
to your skin. Immediately take
off the clothing and follow the
procedure above if necessary.
●If you accidentally swallow elec-
trolyte
Drink a large quantity of water
or milk. Get emergency medical
attention immediately.
■When disconnecting the
12-volt battery
Do not disconnect the negative (-)
terminal on the body side. The
disconnected negative (-) terminal
may touch the positive (+) termi-
nal, which may cause a short and
result in death or serious injury.
NOTICE
■When recharging the 12-volt
battery
Never recharge t he 12-volt bat-
tery while the hybrid system is
operating. Also, be sure all acces-
sories are turned off.
Adding the washer fluid

3476-3. Do-it-yourself maintenance
6
Maintenance and care
ment may be required. (For sched-
uled maintenance information,
please refer to the “Scheduled
Maintenance Guide” or “Owner’s
Manual Supplement”.)
■If air flow from the vents
decreases dramatically
The filter may be clogged. Check
the filter and replace if necessary.
■Scheduled maintenance of the
air intake vent is necessary
when
In some situations such as when the
vehicle is used frequently or in
heavy traffic or dusty areas, the air
intake vent may need to be cleaned
more regularly. For d etails, refer to
“Scheduled Maintenance Guide” or
“Owner’s Manual Supplement”.
■Cleaning the air intake vent
Improper handling of the air intake
vent cover and filter may result in
damage to them. If you have any
concerns about cleaning the filter,
contact your Toyota dealer.
NOTICE
■When using the air condition-
ing system
Make sure that a filter is always
installed.
Using the air conditioning system
without a filter may cause damage
to the system.
■To prevent damage to the fil-
ter cover
When moving the filter cover in
the direction of arrow to release
the fitting, pay attention not to
apply excessive force to the
claws. Otherwise, the claws may
be damaged.
Cleaning the hybrid
batter y (traction bat-
ter y) air intake vents
To prevent the fuel economy
from being affected, visually
inspect the hybrid battery
(traction battery) air intake
vents periodically for clogs.
If it is dusty or clogged or if
“Maintenance Required for
Traction Battery Cooling
Parts See Owner’s Manual”
is displayed on the
multi-information display,
clean the air intake vent
using the following proce-
dures:

3486-3. Do-it-yourself maintenance
1Turn the power switch off.
2 Remove the air intake vent
cover.
Pull the cover as shown in
the illustration to disengage
the 7 claws, starting from the
claw in the upper right corner.
Pull the cover toward the
front of the vehicle to remove
it. 3
Remove the filter from the air
intake vent cover.
Disengage the claw as
shown in the illustration.
Remove the filter from the
cover.
If dust has accumulated on the
air intake vent cover, remove the
dust with a vacuum cleaner, etc.
4 Remove the dust and sand
from the filter.
Using a vacuum cleaner, etc.,
absorb dust and sand from the filter
by profiling the nozzle lightly along
the fold.
5Hold the filter to the light and
check if it is not clogged.
If the dust or sand cannot be
removed completely, contact your
NOTICE
■If “Maintenance Required for
Traction Battery Cooling
Parts See Owner’s Manual” is
displayed on the multi-infor-
mation display
Clean the air intake vent immedi-
ately.
If the vehicle is continuously
driven with the warning message
displayed, it may cause a mal-
function or output restriction of the
hybrid battery (tr action battery).
Cleaning procedure

3496-3. Do-it-yourself maintenance
6
Maintenance and care
Toyota dealer.
6Install the filter in its original
position, and then install the
air intake vent cover.
If “Maintenance Required for
Traction Battery Cooling Parts
See Owner’s Manual” is dis-
played on the multi-informa-
tion display
7 Start the hybrid system and
check that the warning mes-
sage is no longer displayed.
It may be necessary to drive the
vehicle for warning message is dis-
played again then disappears.
If the warning message does not
disappear after some time, have
the vehicle inspected by your Toy-
ota dealer.
■If the dust or sand on the filter
cannot be removed
It is recommended to use a vacuum
cleaner with plastic brushes.
WARNING
■When cleaning the air intake
vent
●Do not use water or other liq-
uids to clean the air intake vent.
If water is applied to the hybrid
battery (traction battery) or
other components, a malfunc-
tion or fire may occur.
●Before cleaning the air intake
vent, make sure to turn the
power switch off to stop the
hybrid system.
●Do not put a han d or leg in the
air intake vent. If it is caught in a
cooling fan, or if it touches a
high voltage part that results in
an electric shock, death or seri-
ous injuries may result.
NOTICE
■When cleaning the air intake
vent
Do not use an ai r blow gun, etc.
Dust may be blown out, possibly
causing a malfunction or output
restriction of the hybrid battery
(traction battery).
■To prevent damage to the
vehicle
Observe the following precau-
tions:
●Do not allow liquid or foreign
material to enter the air intake
vent.
●Make sure to reinstall the filter
and cover to their original posi-
tions after cleaning.
●Do not install anything to the air
intake vent other than the exclu-
sive filter for this vehicle or use
the vehicle witho ut the filter
installed.

3506-3. Do-it-yourself maintenance
■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.
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2032 (vehi-
cles without a smart key sys-
tem), or CR2450 (vehicles
with a smart key system)
■Use a CR2032 (vehicles without
a smart key system), or CR2450
(vehicles with a smart key sys-
tem) 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 manufacturer.
NOTICE
■To prevent damage to the fil-
ter
Observe the following precau-
tions.
If the filter is damaged, have it
replaced with a new filter by your
Toyota dealer.
●Do not use an air blow gun, etc.
●Do not press hard a vacuum
cleaner, etc.against the filter.
●Do not use a hard brush, such
as a metal brush.
●Do not break the fold of the fil-
t er.
Wireless remote con-
trol/electronic key bat-
ter y
Replace the battery with a
new one if it is depleted.
As the key may be damaged
if the following procedure is
not performed properly, it is
recommended that key bat-
tery replacement be per-
formed by your Toyota
dealer.
Items to prepare