2023 TOYOTA BZ4X radiator

742-1. Electric vehicle system
Owners Manual_USA_M42C01_en
■Charging the traction battery
Be sure to maintain the traction bat-
tery charge level suitable for your
driving needs.
If the traction battery fully dis-
charges, the vehicle cannot be
driven at all. When the battery
becomes low, charge it as soon as
possible.
■If the traction battery becomes
low
●If the traction battery becomes
low, the traction battery charge
warning light comes on or flashes
and a message will be displayed
on the multi-information display.
(  P.515)
●If the traction batte ry is completely
discharged, the EV system cannot
be started and dri ving will not be
possible. When the traction bat-
tery becomes low, charge it as
soon as possible.
■Sounds and vibrations specific
to an battery electric vehicle
Because there is no engine sound
or vibration, it is easy to mistake the
battery electric vehi cle for being off
when it is actually still running, as
indicated by the “READY” indicator
being illuminated. F or safety, make
sure to always shift the shift position
to P and apply the parking brake
when parked.
Before and after the EV system is
started, the following sounds and
vibrations may occur. However,
these sounds and/o r vibrations are
not signs of malfunctions:
●The brake system operation
sound may be heard from the
front of the vehicle when the
driver’s door is opened.
●Motor sounds may be heard from
the motor compartment or lug-
gage compartment.
●Electrical relay sounds may be
heard from the motor compart-
ment when the EV system starts or stops.
●Relay operating sounds such as a
snap or soft clank will be emitted
from the traction b
attery in the fol-
lowing situations:
• When the EV system is started or stopped
• When charging starts or com-
pletes
• When the vehicle is driven the first time after the traction battery has
been charged using DC charging
●Sounds may be heard due to
regenerative braking when the
brake pedal is depressed or as
the accelerator pedal is released.
●Cooling fan operating sounds
from the radiator.
●The operation sound of the air
conditioning system (air condition-
ing compressor, blower motor).
■Maintenance, repair, recycling,
and disposal
Contact your Toyota dealer regard-
ing maintenance, repair, recycling
and disposal. Do n ot dispose of the
vehicle yourself.
A sound which changes in
accordance with the driving
speed, will be played in order to
warn people nearby of the vehi-
cle’s approach. This sound may
be heard inside the vehicle. The
sound will stop when the vehicle
speed exceeds approximately
23 mph (37 km/h).
■Acoustic Vehicle Alerting Sys-
tem
In the following cases, the Acoustic
Vehicle Alerting System may be dif-
ficult for surrounding people to hear.
Acoustic Vehicle Alerting
System

762-1. Electric vehicle system
Owners Manual_USA_M42C01_enThe illustration is an example fo
r explanation and may differ from the actual
item.
Warning label
High voltage cables (orange)
ESU: Electricity Supply Unit (built in onboard traction battery
charger/DC-DC converter)
Service plug
AC charging inlet
Electric Vehicle system precautions
Be careful of the high voltage components (nominal voltage
at 355.2 V), such as the traction battery, electricity supply
unit, orange colored high voltage cables, and electric motor,
as well as high temperature components such as the cooling
radiator, which are provided on the battery electric vehicle.
For the high voltage components, warning labels are pro-
vided on them. Read them when they need to be handled.
System components

4577-2. Maintenance
Owners Manual_USA_M42C01_en
7
Maintenance and care
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
(  P.466)
Washer fluid
Is there sufficient
washer fluid?
( P.471)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Transmission
“Park” mecha-
nism
• When parked on a slope and the
shift position is in
P, is the vehicle
securely
stopped?
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have
appropriate
clearance from
the floor?
• Does the brake pedal have the
correct amount
of free play?
ItemsCheck points
Brakes
• The vehicle should not pull to
one side when
the brakes are
applied.
• The brakes should work
effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get
too close to the
floor when the
brakes are
applied.
Head
restraints
• Do the head restraints move
smoothly and
lock securely?
Indica-
tors/buzzers
• Do the indica-tors and buzzers
function prop-
erly?
Lights
• Do all the lights come on?
• Are the head- lights aimed cor-
rectly?
Parking brake
• Does the park-ing brake oper-
ate normally?
• When parked on a slope and the
parking brake is
on, is the vehicle
securely
stopped?
ItemsCheck points

4617-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
7
Maintenance and care
Heater cool-
ant level
(  P.465)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene glycol-based
non-silicate, non-
amine, non-nitrite
and non-borate
coolant with long-
life hybrid organic
acid technology
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% coolant
and 50% deion-
ized water.
• Funnel (used only for adding coolant)
Fuses
( P.499)• Fuse with same
amperage rating
as original
Headlight aim
( P.501)Phillips-head
screwdriver
Radiator and
condenser
( P.466)

Tire inflation
pressure
( P.491)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.471)
• Water or washer
fluid containing
antifreeze (for win-
ter use)
• Funnel (used only for adding water or
washer fluid)
ItemsParts and toolsWARNING
The motor 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 motor
compartment
●Make sure that “POWER ON”
on the multi-information display
and the “READY” indicator are
both off.
●Keep hands, clothing and tools
away from the moving fan.
●Be careful not to touch the
motor, power control unit, radia-
tor, etc., right after driving as
they may be hot. Coolant and
other fluids may also be hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the motor compartment.
●Do not smoke, cause sparks or
expose an open flame to the 12-
volt battery. 12-volt battery
fumes are flammable.
●Be extremely cautious when
working on the 12-volt battery. It
contains poisonous and corro-
sive sulfuric acid.
●Never touch, disassemble,
remove or replace the high volt-
age parts, cables and their con-
nectors. It can cause severe
burns or electric shock that may
result in death or serious injury.

4627-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
1Pull the hood lock release
lever.
The hood will pop up slightly.
2Push the auxiliary catch lever
to the left and lift the hood.
WARNING
■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 fan may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. ( P.466)
■Safety glasses
Wear safety glasses to prevent
flying or falling material, fluid
spray, etc., from getting in your
eyes.
Hood
Opening the hood

4657-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
7
Maintenance and care
Heater coolant reservoir ( P.465)
Washer fluid tank ( P.471)
Power control unit coolant reservoir ( P.467)
12-volt battery ( P.468)
Brake fluid reservoir ( P.468)
Fuse box ( P.499)
Radiator ( P.466)
Condenser ( P.466)
Electric cooling fan
The coolant level is satisfactory
if it is between the “MAX” and “MIN” lines on the reservoir
when the EV system is cold.
Motor compar tment
Components
Checking the heater cool-
ant

4667-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
Reservoir cap
“MAX” line
“MIN” line
If the level is on or below the “MIN”
line, add coolant up to the “MAX”
line. (P.545)
■Coolant selection
Only use “Toyota Super Long Life
Coolant” or a similar high quality
ethylene glycol based non-silicate,
non-amine, non-nitrite, and nonbo-
rate coolant with long-life hybrid
organic acid technology.
“Toyota Super Long Life Coolant” is
a mixture of 50% coolant and 50%
deionized water. (Minimum tem-
perature: -31°F [-35°C])
For more details about coolant, con-
tact your Toyota dealer.
■If the coolant level drops within
a short time of replenishing
Visually check the radiator, hoses,
power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have your
Toyota dealer, test the cap and
check for leaks in the cooling sys-
tem.
Check the radiator and con-
denser and clear away any for-
eign objects.
If either of the above parts is
extremely dirty or you are not
sure of their condition, have
your vehicle inspected Toyota
dealer.
WARNING
■When the heater system is
hot
Do not remove the heater coolant
reservoir caps.
The heater system may be under
pressure and may spray hot cool-
ant if the cap is removed, causing
serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct
mixture of water and antifreeze
must be used to provide proper
lubrication, corrosion protection
and cooling. Be sure to read the
antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to
prevent it from damaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the EV system is hot
Do not touch the radiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.

4677-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
7
Maintenance and care
The coolant level is satisfactory
if it is between the “MAX” and
“MIN” lines on the reservoir
when the EV system is cold. Reservoir cap
“MAX” line
“MIN” line
If the level is on or below the “MIN”
line, add coolant up to the “MAX”
line.
■Coolant selection
In order to ensure maximum perfor-
mance of the traction battery cooling
system and limit risks of battery
short-circuit and other damage to your vehicle, Toyota recommends
using “Toyota Genuine Traction Bat-
tery Coolant” or similar high-quality
ethylene glycol-based, low electric
conductivity coolant, non-amine and
non-borate coolant with azole addi-
tives.
Toyota cannot guarantee that the
use of a product o
ther than “Toyota
Genuine Traction Battery Coolant”
will prevent risks of battery short-cir-
cuit or other damage.
Never use water as it will cause
damage.
Do not reuse cool ant that has been
removed from the radiator.
For more details about coolant, con-
tact your Toyota dealer.
■If the coolant level drops within
a short time of replenishing
Visually check the hoses, heater
coolant reservoir caps, drain cock
and water pump.
If you cannot find a leak, have your
Toyota dealer, t est the cap and
check for leaks in the cooling sys-
tem.
WARNING
■When the electric cooling fan
are operating
Do not touch the motor compart-
ment.
With the power switch in ON, the
electric cooling fan may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. Be sure the
power switch is OFF when work-
ing near the electric cooling fan or
radiator grille.
Checking the power con-
trol unit coolant
WARNING
■When the EV system is hot
Do not remove the power control
unit coolant reservoir caps.
The cooling system may be under
pressure and may spray hot cool-
ant if the cap is removed, causing
serious injuries, such as burns.