2021 TOYOTA HIGHLANDER HYBRID battery

4126-3. Do-it-yourself maintenance
HIGHLANDER HV_U
6-3.Do-it-yourself maintenance
Do-it-yourself ser vice
precautions
If you perform maintenance
by yourself, be sure to fol-
low the correct procedure
as given in these sections.
Maintenance
ItemsParts and tools
12-volt battery
condition
( P.421)
•Grease
• Conventional
wrench (for ter-
minal clamp
bolts)
Brake fluid
level ( P.420)
• FMVSS No.116
DOT 3 or SAE
J1703 brake fluid
• Rag or paper towel
• Funnel (used only for adding
brake fluid)
Engine/power
control unit
coolant level
( P.418)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene gly-
col-based
non-silicate,
non-amine,
non-nitrite and
non-borate cool-
ant with long-life
hybrid organic
acid technology
For the U.S.A.:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% cool-
ant and 50%
deionized water.
For Canada:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 55% cool-
ant and 45%
deionized water.
• Funnel (used only for adding
coolant)
Engine oil level
( P.416)
• “Toyota Genuine
Motor Oil” or
equivalent
• Rag or paper towel
• Funnel (used only for adding
engine oil)
Fuses
( P.446)• Fuse with same
amperage rating
as original
ItemsParts and tools

4136-3. Do-it-yourself maintenance
6
Maintenance and care
HIGHLANDER HV_U
Hybrid battery
(traction bat-
tery) air intake
vent (P.441)• Vacuum cleaner,
etc.
• Phillips screw- driver
Headlight aim
( P.448)• Phillips-head
screwdriver
Light bulbs
( P.449)
• Bulb with same
number and
wattage rating as
original
• Phillips-head screwdriver
• Flathead screw- driver
• Wrench
Radiator and
condenser
(  P.419)

Tire inflation
pressure
( P.436)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.420)
• Water or washer
fluid containing
antifreeze (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.
ItemsParts and tools■When working on the engine
compartment
●Make sure that the “ACCES-
SORY” or “IGNITION ON” on
the multi-information display
and the “READY” indicator are
both off.
●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.
Fuel fumes are flammable.
■When working near the elec-
tric cooling fan or radiator
grille
Be sure the power switch is off.
With the power switch in ON, the
electric cooling fa n may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. ( P.419)
■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.

4166-3. Do-it-yourself maintenance
HIGHLANDER HV_U
Engine coolant reservoir ( P.418)
Fuse boxes ( P.446)
Engine oil filler cap ( P.417)
Engine oil level dipstick ( P.417)
Brake fluid reservoir ( P.420)
Washer fluid tank ( P.420)
Electric cooling fan
Condenser ( P.419)
Radiator ( P.419)
Power control unit coolant reservoir ( P.419)
■12-volt battery
 P. 4 2 1
With the engine at operating
temperature and turned off,
check the oil level on the dip-
Engine compar tment
Components
Checking and adding the
engine oil

4216-3. Do-it-yourself maintenance
6
Maintenance and care
HIGHLANDER HV_U
The 12-volt battery is located in
the right-hand side of luggage
compartment.
Open the deck board.
Disengage the 8 claws and pull
the side deck board to remove
it.
WARNING
■When adding washer fluid
Do not add washer fluid when the
hybrid system is hot or operating
as washer fluid contains alcohol
and may catch fire if spilled on the
engine, etc.
NOTICE
■Do not use any fluid other
than washer fluid
Do not use soapy water or engine
antifreeze instead of washer fluid.
Doing so may cause streaking on
the vehicle’s painted surfaces, as
well as damaging the pump lead-
ing to problems of the washer
fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as
necessary.
Refer to the freezing tempera-
tures listed on the label of the
washer fluid bottle.
12-volt batter y
Location
Before removing the
12-volt battery cover
Removing the 12-volt bat-
tery cover

4226-3. Do-it-yourself maintenance
HIGHLANDER HV_U
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 power switch on
the charger is off when connecting
and disconnecting the charger
cables to the 12-volt battery.
■After recharging/reconnecting
the 12-volt battery
The hybrid system may not start.
Follow the procedure below to ini-
tialize the system.
1 Shift the shift lever to P.
2 Open and close any of the doors.
3 Restart the hybrid 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 disconnect the
12-volt battery. Take extra care
when connecting the 12-volt bat-
tery if the power switch mode prior
to discharge is unknown.
If the system will not start even after
multiple attempts at all the methods
above, contact you r Toyota dealer.
Exterior
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:

4236-3. Do-it-yourself maintenance
6
Maintenance and care
HIGHLANDER HV_U
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.
■How to recharge the 12-volt
battery
Only perform a slow charge (5 A
or less). The 12-volt battery may
explode if charged at a quicker
rate.
■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. Imm ediately 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 replacing the 12-volt
battery
Use a 12-volt battery designed for
this vehicle. Failu re to do so may
cause gas (hydrogen) to enter the
passenger compartment, causing
a fire or explosion.
For replacement of the 12-volt
battery, contact your Toyota
dealer.
■When handling the 12-volt
battery
P. 5 0 2
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.

4416-3. Do-it-yourself maintenance
6
Maintenance and care
HIGHLANDER HV_U
Remove the dust from the air
intake vent with a vacuum
cleaner, etc.
Make sure to only use a vacuum to
suck out dust and clogs. Attempting
to blow out dust and clogs using an
airgun, etc. may push it into the air
intake vent. (P.443)
If dust and clogs cannot be com-
pletely removed with the air
intake vent cover installed,
remove the cover and clean the
filter.
1 Turn the power switch off.
2 Remove the air intake vent
cover.
Pull the cover as shown in the illus-
tration to disengage the 6 claws,
starting from the claw in the upper
right corner and pull the cover
toward the front of the vehicle to
remove it.
3 Remove the air intake vent
filter.
Disengage the claw to remove the
filter from the rear scuff plate.
Cleaning the hybrid
batter y (traction bat-
ter y) air intake vents
and filter
To prevent the fuel economy
from being affected, visually
inspect the hybrid battery
(traction battery) air intake
vents periodically for dust
and clogs. If it is dusty or
clogged or if “Maintenance
Required for Traction Bat-
tery Cooling Parts See
Owner’s Manual” is shown
on the multi-information
display, clean the air intake
vent using the following
procedures:
Cleaning the air intake
vents
If dust and clogs cannot
be completely removed

4426-3. Do-it-yourself maintenance
HIGHLANDER HV_U
4Remove the dust and clogs
from the filter using a vacuum
cleaner, etc.
Make sure to also remove the dust
and clogs from the inside of the air
intake vent cover.
5Reinstall the filter to the
cover.
Engage the 3 claw to install the fil-
ter.
Make sure that t he filter is not
crooked or deformed when install-
ing it.
6 Install the air intake vent
cover.
I ns er t t he t ab o f th e co ve r a s sh ow n
in the illustrati on and push the cover to enga
ge the 6 claws.
■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”.
■Cleaning the air intake vent
●Dust in the air intake vent may
interfere with the cooling of the
hybrid battery (trac tion battery). If
charging/discharging of the hybrid
battery (traction battery) becomes
limited, the distance that the vehi-
cle can be driven using the electric
motor (traction motor) may be
reduced and the fuel economy
may be reduced. Inspect and
clean the air intake vent periodi-
cally.
●Improper handling of the air intake
vent cover and filt er may result in
damage to them. If you have any
concerns about cleaning the filter,
contact your Toyota dealer.
■If “Maintenance Required for
Traction Battery Cooling Parts
See Owner’s Manual” is shown
on the multi-information display
●If this warning message is shown
on the multi-information display,
remove the air intake vent cover
and clean the filter. ( P.441)
●After cleaning the air intake vent,
start the hybrid system and check