cooling Lexus ES300h 2020 User Guide

3456-3. Do-it-yourself maintenance
6
Maintenance and care
8Using a Phillips screwdriver, install
the clip.
■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 details, refer to “Owner’s Manual Sup-
plement” or “Scheduled Maintenance”.
■Cleaning the air intake vent
●Dust in the air intake vent may interfere
with the cooling of the hybrid battery
(traction battery). If charging/discharging
of the hybrid battery (traction battery)
becomes limited, the distance that the
vehicle 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 peri-
odically.
●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 Lexus
dealer.
■If “Maintenance required for Traction
battery cooling parts See owner’s man-
ual” is displayed on the multi-informa-
tion display
●If this warning message is displayed on
the multi-information display, remove the
air intake vent cover and clean the filter.
(  P.343)
●After cleaning the air intake vent, start
the hybrid system and check that the
warning message is no longer displayed.
After the hybrid system is started, it may be necessary to drive the vehicle up to
approximately 20 minutes before the
warning message disappears. If the warn-
ing message does not disappear after
driving for appropriately 20 minutes,
have the vehicle inspected by your Lexus
dealer.
WARNING
■When cleaning the air intake vent
●Do not use water or other liquids to
clean the air intake vent. If water is
applied to the hybrid battery (traction
battery) or other components, a mal-
function or fire may occur.
●Before cleaning the air intake vent,
make sure to turn the power switch off
to stop the hybrid system.
■When removing the air intake vent
cover
Do not touch the service plug located
near the air intake vent. ( P.64)
NOTICE
■When cleaning the air intake vent
When cleaning the air intake vent, make
sure to only use a vacuum to suck out
dust and clogs. If a compressed air blow
gun, etc. is used to blow out dust and
clogs, the dust or clogs may be pushed
into the air intake ve nt, which may affect
the performance of the hybrid battery
(traction battery) and cause a malfunc-
tion.

3466-3. Do-it-yourself maintenance
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operational range will be reduced.
Prepare the following before replacing
the battery:
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent
type recommended by the manufacturer.
●Dispose of used batteries according to
the local laws.
1Take out the mechanical key.
NOTICE
■To prevent damage to the vehicle
●Do not allow water or foreign matter to
enter the air intake vent when the
cover is removed.
●Carefully handle the removed filter so
that it will not be damage.
If the filter is damaged, have it replaced
with a new filter by your Lexus dealer.
●Make sure to reinstall the filter and
cover to their original positions after
cleaning.
●Do not install anything to the air intake
vent other than the exclusive filter for
this vehicle or use the vehicle without
the filter installed.
■If “Maintenance Required for Trac-
tion Battery Cooling Parts See
Owner’s Manual” is displayed on the
multi-information display
If the vehicle is continuously driven with
the warning message (indicating that
charging/discharging of the hybrid bat-
tery (traction battery) may become lim-
ited) displayed, the hybrid battery
(traction battery) may malfunction.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare
Replacing the battery

3777-2. Steps to take in an emergency
7
When trouble arises
the driven distance on the maintenance
schedule* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( P.312)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all maintenance is required to
correspond to the driven distance on the
maintenance schedule
*.
Comes on approximately 5000 miles
(8000 km) after the message has been
reset. (The indicator will not work properly
unless the message ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( P.312)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Oil Maintenance Required Soon” is
displayed
Indicates that the engine oil should be
scheduled to be changed.
Check the engine oil and change it if neces-
sary. After changing the engine oil, make
sure to reset the message. ( P.312)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed.
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, make sure to reset the message.
(  P.323)
■If a message that in dicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the multi-
information display is malfunctioning. Have the vehicle inspected by your Lexus dealer
immediately.
■If a message that indicates the need for
referring to Owner’
s Manual is dis-
played
●If any of the following messages are
shown on the multi-information display,
follow the instructions.
• “Engine Coolant Temp High” ( P.395)
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malf unction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Access System with Elec. Key Malfunc-
tion”
• “Hybrid system malfunction”
•“Check Engine”
• “Hybrid battery system malfunction”
• “Accelerator system malfunction”
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfun ction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”
• “Hybrid system stopped”
• “Engine stopped”
●If “Low Auxiliary Battery” is shown
• When the display goes off after several
seconds
*:
Maintain the hybrid system operation for
more than 15 minutes and charge the 12-
volt battery.
• When the display does not go off:
Start up the hybrid system using the proce-
dures for “If the 12-volt battery is dis-
charged” ( P.390).
*: Displays for about 6 seconds
●If “Maintenance required for Traction bat-
tery cooling parts” is shown, the filter may
be clogged, the air intake vent may be
blocked, or there may be a gap in the
duct. Therefore, perform the following
correction procedure.
• If the air intake vent s and filters of the
hybrid battery (traction battery) are dirty,

3947-2. Steps to take in an emergency
WARNING
●In the event that 12-volt battery fluid
comes into contact with the skin or
eyes, immediately wash the affected
area with water and seek medical
attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your hands after handling
the 12-volt battery support, terminals,
and other battery-related parts.
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible. If
the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When exchanging the 12-volt battery
●When the vent plug and indicator are
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.
●After exchanging, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the exchanged 12-
volt battery. If not properly installed,
gases (hydrogen) may leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fan or engine drive
belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another vehicle in an emer-
gency. It cannot be used to jump start
another vehicle.

3957-2. Steps to take in an emergency
7
When trouble arises
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.76) 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

3967-2. Steps to take in an emergency
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

3977-2. Steps to take in an emergency
7
When trouble arises
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 overheated
Output power reduced” is shown
on the multi-information display.
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 message appears again fre-
quently, 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 damage to the hybrid
system.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust
etc.).
●Do not use any coolant additive.

4038-1. Specifications
8
Vehicle specifications
cold startability. Oils with a lower
value before the W allow for easier
starting of the engine in cold
weather.
• The 16 in 0W-16 indicates the vis- cosity characteristic of the oil when
the oil is at high temperature. An oil
with a higher viscosity (one with a
higher value) may be better suited if
the vehicle is operated at high
speeds, or under extreme load con-
ditions. How to read oil container label:
API registered marks is added to some
oil containers to help you select the oil
you should use.
*: The fluid capacity is a reference quantity.
If replacement is necessary, contact your Lexus dealer.
■Spark plug
Cooling system
Capacity*
Gasoline engine
6.4 qt. (6.1 L, 5.4 Imp.qt.)
Power control unit
1.9 qt. (1.8 L, 1.6 Imp.qt.)
Coolant type
Use either of the following:
 “Toyota Super Long Life Coolant”
 Similar high-quality ethylene glycol-
based non-silicate, non-amine, non-
nitrite, and non-borate coolant with long-
life hybrid organic acid technology
Do not use plain water alone.
Ignition system
MakeDENSO FC16HR-Q8
Gap0.031 in. (0.8 mm)

448Alphabetical index
Exterior ...........................................................306
Interior .............................................................309
Seat belts........................................................309
Cargo capacity................................................ 141
Cargo hooks ................................................. 283
Center Display ............................................. 258
Chains .............................................................. 254
Child-protectors............................................102
Child restraint system................................... 42 Fixed with a LATCH system .................. 49
Fixed with a seat belt................................... 46
Front passenger occupant classification system ..............................................................37
Points to remember .....................................42
Riding with children ......................................42
Types of child restraint system installation method ........................................................... 43
Using an anchor bracket ............................ 51
Child safety ....................................................... 42 12-volt battery precautions ....... 327, 393
Airbag precautions...................................... 33
Child restraint system................................. 43
Heated steering wheel and seat heater
precautions................................................ 273
How your child should wear the seat belt ............................................................................ 25
Moon roof precautions ............................. 131
Power window lock switch..................... 129
Power window precautions ................... 129
Rear door child-protectors ....................102
Removed electronic key battery precau- tions ............................................................... 347
Seat belt extender precautions ............. 25
Seat belt precautions ...................................42
Trunk precautions ...................................... 103
Cleaning.............................................. 306, 309 Aluminum wheels ......................................306
Exterior ...........................................................306
Interior .............................................................309
Radar sensor......................................172, 208
Seat belts........................................................309
Clock ........................................................ 76, 284 Coat hooks..................................................... 295
Compass ......................................................... 302
Condenser ..................................................... 324
Console box ....................................................281
Console box light ..........................................281
Cooling system............................................. 323
Engine overheating.................................. 395
Hybrid system overheating ................. 396
Cornering lights .............................................. 161 Replacing light bulbs ................................. 351
Cruise control Dynamic radar cruise control with full-
speed range ............................................... 196
Cup holder .......................................................281
Current fuel consumption .......................... 80
Curtain shield airbags .................................. 28
Customizable features ............................... 418
D
Daytime running light system ...................159
Defogger Outside rear view mirrors.....................266
Rear window ................................................266
Windshield ....................................................266
Dimension ......................................................400
Dinghy towing................................................. 142
Display BSM (Blind Spot Monitor)................... 206
Dynamic radar cruise control with full-
speed range ............................................... 196
Energy monitor ............................................. 88
Head-up display............................................84
Intuitive parking assist ............................... 215
LTA (Lane-Tracing Assist) .................... 190
Multi-information display .......................... 79
Parking Support Brake function (rear
pedestrians)............................................... 244
RCD (Rear Camera Detection) ........ 225
RCTA................................................................. 221
Warning message ..................................... 374
Distance until next engine oil change .... 78
Do-it-yourself maintenance ......................313