radiator cap Lexus ES300h 2019 Owner's Manual (OM06178U)

3186-3. Do-it-yourself maintenance
Fuse boxes (P.341)
Engine oil filler cap ( P.319)
Engine oil level dipstick ( P.318)
Brake fluid reservoir ( P.322)
Radiator ( P.321)
Electric cooling fan
Condenser ( P.321)
Power control unit coolant reservoir ( P.321)
Engine coolant reservoir ( P.320)
Washer fluid tank ( P.322)
■12-volt battery
 P.323
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

3216-3. Do-it-yourself maintenance
6
Maintenance and care
Reservoir cap
“F” line
“L” line
If the level is on or below the “L” line, add
coolant up to the “F” line. ( P.389)
■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.390)
■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 reservoir
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 en gine/power control
unit coolant reservoir caps or the radia-
tor cap. ( P.391)
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 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 pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser

3897-2. 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.70) 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

3917-2. 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.

448Alphabetical index
Warning light ............................................... 364
Warning message....................................... 147
Parking lights .................................................. 150 Light switch .................................................... 150
Parking Support Brake function (rear- crossing vehicles) ........................... 218, 229Function .......................................................... 229
Parking Support Brake function (rear pedestrians) ...................................... 218, 233Function .......................................................... 233
Parking Support Brake function (static objects) ............................................... 218, 224Function .......................................................... 224
PCS (Pre-Collision System) .....................169 Function ............................................................169
PCS OFF switch ............................................171
Warning light ............................................... 364
Personal lights............................................... 265
PKSA (Parking Support Alert) .............. 204
PKSB (Parking Support Brake)...............218 Warning message......................................222
Power control unit.......................................... 56
Power control unit coolant ...................... 320
Capacity ......................................................... 397
Checking ....................................................... 320
Preparing and checking before winter......................................................................... 242
Power easy access system ......................... 110
Power outlet ...................................................272
Power steering (Elect ric power steering
system).......................................................... 236 Warning light ...............................................360
Power switch ...................................................135 Auto power off function ........................... 137
Changing the power switch modes .. 137
If your vehicle has to be stopped in an
emergency ............................................... 350
Starting the hybrid system.......................135
Power trunk lid ................................................ 95
Power windows ..............................................120 Door lock linked window operation....121
Jam protection function..............................121 Operation ....................................................... 120
Window lock switch.................................... 121
Pre-Collision System (PCS) .....................169 Function ........................................................... 169
PCS OFF switch ........................................... 171
Warning light ...............................................364
R
Radar cruise control (dynamic radar cruise control with full-speed range)...............187
Radiator .............................................................321
RCD (Rear Camera Detection) ........... 204 Function ........................................................... 215
Warning message .......................................216
RCTA (Rear Cross Traffic Alert) .204, 211
RCTA Function ............................................................. 211
Warning message ....................................... 212
Rear Cross Traffic Alert (RCTA) .204, 211
Rear door sunshades ...................................281
Rear seats Head restraints............................................... 113
Rear side marker lights .............................. 150 Light switch .................................................... 150
Rear sunshades ..............................................281
Rear turn signal lights ..................................145 Replacing light bulbs ................................344
Turn signal lever .......................................... 145
Rear view mirror Inside rear view mirror ............................... 116
Outside rear view mirrors........................ 117
Rear window defogger ............................. 254
Refueling ............................................................ 161 Capacity ........................................................ 395
Fuel types ...................................................... 395
If the fuel filler do or cannot be opened
........................................................................... 381
Opening the fuel tank cap ....................... 161
Regenerative braking ................................... 54
Remote Touch .............................................. 246
Replacing Electronic key battery ..............................339