2023 TOYOTA BZ4X coolant reservoir

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.

4687-3. Do-it-yourself maintenance
Owners Manual_USA_M42C01_en
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
Reservoir cap
“MAX” line
“MIN” line
■Adding fluid
Make sure to check the fluid
type and prepare the necessary
item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703 brake fluid
FMVSS No.116 DOT 4 or SAE
J1704 brake fluid

Item
Clean funnel
■Brake fluid can absorb moisture
from the air
Excess moisture in the brake fluid
can cause a dangerous loss of brak-
ing efficiency. Use only newly
opened brake fluid.
Check the 12-volt battery as fol-
lows.
■12-volt battery exterior
Make sure that the 12-volt bat-
tery terminals are not corroded
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 d amaging parts or
paint.
Checking and adding the
brake fluidWARNING
■When filling the reservoir
Take care as brake fluid can harm
your hands and eyes and damage
painted surfaces.
If fluid gets on your hands or in
your eyes, flush the affected area
with clean water immediately. If
you still experience discomfort,
see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level
to go down slight ly as the brake
pads wear out or when the fluid
level in the accumulator is high.
If the reservoir needs frequent
refilling, there m ay be a serious
problem.
Checking the 12-volt bat-
tery

5468-2. Steps to take in an emergency
Owners Manual_USA_M42C01_en
pears and then stop the EV
system. If the message does
not disappear, call your Toy-
ota dealer.
If the fan is not operating:
Stop the EV system immedi-
ately and call your Toyota
dealer.
4 After the EV system has
cooled down, inspect the
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately cont act your Toyota
dealer.
5 The coolant level is satisfac-
tory if it is between the “MAX”
and “MIN” lines on the reser-
voir. Reservoir
“MAX” line
“MIN” line
6 If the coolant is insufficient,
replenish with “Toyota Genu-
ine Traction Battery Coolant”.
If you don’t have “Toyota Genuine
Traction Battery Coolant”, contact
your Toyota dealer.
1Remove the bolt.
2 Open the reservoir cap
Have the vehicle inspected at
the nearest your Toyota dealer.
WARNING
■To prevent an accident or
injury when inspecting under
the hood of your vehicle
Observe the following precau-
tions.
Failure to do so may result in seri-
ous injury such as burns.
●If steam is seen coming from
under the hood, do not open the
hood until the steam has sub-
sided. The motor compartment
may be very hot.