2021 LEXUS ES300h radiator

3146-2. Maintenance
Radiator/con-
denser
The radiator and con-
denser should be free
from foreign objects.
( P.324)
Washer fluid
Is there sufficient
washer fluid?
( P.325)
Trunk
ItemsCheck points
12-volt battery
Check the battery fluid
level and connections.
( P.326)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should move
smoothly (without
uneven pedal effort
or catching).
Hybrid transmis-
sion “Park” mech-
anism
•When parked on a slope and the shift
lever is in P, is the
vehicle securely
stopped?
Brake pedal
•Does the brake pedal move
smoothly?
•Does the brake
pedal have appro-
priate clearance
from the floor?
•Does the brake pedal have the cor-
rect 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?
Indicators/buzz-
ers•Do the indicators and buzzers function
properly?
Lights
• Do all the lights come on?
• Are the headlights aimed correctly?
Parking brake
• Does the parking brake operate nor-
mally?
• When parked on a slope and the park-
ing brake is on, is the
vehicle securely
stopped?
Seat belts
• Do the seat belts operate smoothly?
• The seat belts should not be damaged.
ItemsCheck points

3186-3. Do-it-yourself maintenance
Light bulbs
( P.352)
•Bulb with same number
and wattage rating as
original
• Flathead screwdriver
Radiator and
condenser
(  P.324)

Tire inflation
pressure
( P.339)• Tire pressure gauge
• Compressed air source
Washer fluid
( P.325)
• 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 elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Make sure that the “IGNITION ON”
on the multi-information display and
the “READY” indicator are both off.
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
power control unit, radiator, 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 compartment.
ItemsParts and tools●Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable.
■When working near the electric cool-
ing fan or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the
electric cooling fan may automatically
start to run if the air conditioning is on
and/or the coolant temperature is high.
(  P.324)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting 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.

3216-3. Do-it-yourself maintenance
6
Maintenance and care
Fuse boxes (P.349)
Engine oil filler cap ( P.322)
Engine oil level dipstick ( P.321)
Brake fluid reservoir ( P.325)
Radiator ( P.324)
Electric cooling fan
Condenser ( P.324)
Power control unit coolant reservoir ( P.324)
Engine coolant reservoir ( P.323)
Washer fluid tank ( P.325)
■12-volt battery
 P.326
With the engine at operating tempera-
ture and turned off, check the oil level
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
Checking and adding the engine
oil

3246-3. Do-it-yourself maintenance
Reservoir cap
“F” line
“L” line
If the level is on or below the “L” line, add
coolant up to the “F” line. ( P.396)
■Power control unit coolant reser-
voir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
(  P.397)
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite,
and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mix-
ture of 50% coolant and 50% deionized
water. (Minimum temperature: -31°F [-
35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water. (Minimum temperature: -44°F [-
42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses,
engine/power control unit coolant reser-
voir caps, drain cock and water pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects.
If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
A
B
C
A
B
C
WARNING
■When the hybrid system is hot
Do not remove the engine/power con-
trol unit coolant reservoir caps or the
radiator cap. ( P.398)
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neithe r 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 pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser

3256-3. Do-it-yourself maintenance
6
Maintenance and care
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary items.
 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 braking effi-
ciency. Use only newly opened brake fluid.
If any washer does not work or “Wind-
shield Washer Fluid Low” is shown on
the multi-information display, the
washer tank may be empty. Add
washer fluid.
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
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 slightly as the brake pads wear out
or when the fluid leve l in the accumulator
is high.
If the reservoir needs frequent refilling,
there may be a serious problem.
Adding the washer fluid
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.

3967-2. Steps to take in an emergency
If the engine coolant temperature
gauge enters the red zone or
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood. 3
After the hybrid system has cooled
down sufficiently, inspect the hoses
and cooling system for leaks.
Radiator
Cooling fan
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “F” and “L” lines on
the reservoir.
Reservoir
“F” line
“L” line
Coolant inlet cap
5 Add coolant if necessary.
Water can be used in an emergency if
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
The engine coolant temperature
gauge ( P.78) is in the red zone
or a loss of hybrid system power is
experienced. (For example, the
vehicle speed does not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” or “Hybrid system over-
heated Output power reduced” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures
A
B
A
B
C
D

3977-2. Steps to take in an emergency
7
When trouble arises
engine coolant is unavailable.
6Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fan oper-
ates and to check for coolant leaks
from the radiator or hoses.
The fan operates when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fan is operating
by checking the fan sound and air flow. If it
is difficult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fan may not operate in freezing tem-
peratures.)
7 If the fan is not operating:
Stop the hybrid system immediately
and contact your Lexus dealer.
If the fan is operating:
Have the vehicle inspected at the
nearest Lexus dealer.
If “Hybrid system overheated Out-
put power reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood. 3
After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiato r) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4 The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emergency if
A
B
A
B
C

3987-2. Steps to take in an emergency
power control unit coolant is unavailable.
6After stopping the hybrid system
and waiting for 5 minutes or more,
start the hybrid system again and
check if “Hybrid system over-
heated Output power reduced” is
shown on the multi-information dis-
play.
If the message does not disappear:
Stop the hybrid system and contact your
Lexus dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be driven
normally.
However, if the me ssage appears again
frequently, contact your Lexus dealer.
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.
●After the hybrid system has been
turned off, check that the “READY”
indicator are off.
When the hybrid system is operating,
the gasoline engine may automatically
start, or the cooling fan may suddenly
operate even if the gasoline engine
stops. Do not touch or approach rotat-
ing parts such as the fan, which may
lead to fingers or clothing (especially a
tie, a scarf or a muffler) getting caught,
resulting in serious injury.
●Do not loosen the coolant inlet cap or
coolant reservoir caps while the hybrid
system and radiator are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause dama ge to the hybrid
system.
■To prevent damage to the cooling
system
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust
etc.).
●Do not use any coolant additive.