2021 LEXUS ES300h radiator cap

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

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

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.

456Alphabetical index
Parking assist sensors (intuitive parking assist) ............................................................... 216
Parking brake.................................................. 157 Operation........................................................ 157
Parking brake engaged warning buzzer.......................................................................... 158
Warning light ................................................. 371
Warning message...................................... 158
Parking lights .................................................... 161 Light switch ...................................................... 161
Parking Support Brake function (rear- crossing vehicles) ........................... 229, 241Function ............................................................ 241
Parking Support Brake function (rear pedestrians) ..................................... 229, 245Function .......................................................... 245
Parking Support Brake function (static objects) ..............................................229, 235Function .......................................................... 235
PCS (Pre-Collision System) .................... 180 Function ........................................................... 180
PCS OFF switch ..........................................182
Warning light ................................................. 371
Personal lights................................................277
PKSA (Parking Support Alert) ................215
PKSB (Parking Support Brake)............. 229 Warning message..................................... 234
Power control unit.......................................... 64
Power control unit coolant ...................... 323 Capacity .........................................................405
Checking ....................................................... 323
Preparing and checking before winter......................................................................... 254
Power easy access system ........................120
Power outlet .................................................. 284
Power steering (Elect ric power steering
system).......................................................... 248 Warning light ............................................... 367
Power switch ...................................................145 Auto power off function ...........................149
Changing the power switch modes . 148
If your vehicle has to be stopped in an emergency ................................................ 358
Starting the hybrid system ...................... 145
Power trunk lid .............................................. 105
Power windows ............................................. 130 Door lock linked window operation ... 131
Jam protection function ............................. 131
Operation ....................................................... 130
Window lock switch.................................... 131
Pre-Collision System (PCS) .................... 180 Function ........................................................... 180
PCS OFF switch ......................................... 182
Warning light .................................................371
R
Radar cruise control (dynamic radar cruise control with full-speed range).............. 198
Radiator ........................................................... 324
RCD (Rear Camera Detection) .............215 Function .......................................................... 227
Warning message .....................................228
RCTA (Rear Cross Traffic Alert) 215, 222
RCTA Function .......................................................... 222
Warning message ..................................... 223
Rear Cross Traffic Alert (RCTA) 215, 222
Rear door sunshades ................................. 293
Rear seats Head restraints..............................................123
Rear side marker lights ................................ 161 Light switch ...................................................... 161
Rear sunshades ............................................ 293
Rear turn signal lights ..................................156 Replacing light bulbs ................................352
Turn signal lever .......................................... 156
Rear view mirror Inside rear view mirror ..............................126
Outside rear view mirrors....................... 127
Rear window defogger ............................. 266
Refueling ........................................................... 172 Capacity ........................................................ 403
Fuel types ...................................................... 403
If the fuel filler do or cannot be opened