2018 LEXUS LS500H radiator cap

3876-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care
Engine oil level dipstick ( → P.388)
Power control unit coolant reservoir ( → P.390)
Engine coolant reservoir ( → P.390)
Engine oil filler cap ( → P.389)
Brake fluid reservoir ( → P.391)
Fuse boxes ( → P.414)
Washer fluid tank ( → P.392)
Engine coolant radiator ( → P.391)
Power control unit coolant radiator ( → P.391)
Electric cooling fan
Condenser ( → P.391)■
12-volt battery
→ P.393Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
K

3916-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care cold.
Reservoir cap
“F” line
“L” lineIf the level is on or below the “L” line, add
coolant up to the “F” line. ( → P.453)
■
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 condition,
have your vehicle inspected by your
Lexus dealer.
■
Checking fluid level
The brake fluid level should be A
B
C WARNING■
When the hybrid system is hot
Do not remove the en gine/power control
unit coolant reservoir caps. ( → P.456)
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
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

4537-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 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 radiator core (radiator) for any
leaks.
Radiators
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 “F” and “L” lines on
the reservoir.
Reservoir
“F” line
“L” line
Coolant inlet cap
5 Add coolant if necessary.
( → P.455) 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.77, 81) is in the red
zone or a loss of hybrid system
power is experienced. (For exam-
ple, the vehicle speed does not
increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” or “Hybrid System
Overheated Reduced Output
Power” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures A
B
A
B
C
D

456 7-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 6 Add coolant through the inlet of the cap
until it is full, and then replace the
cap .
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 indicator on
the power switch and 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 cl othing (especially a
tie, a scarf or a muffler) getting caught,
resulting in serious injury.●
Do not loosen the coolant inlet cap or
the coolant reservoir cap 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. B
B NOTICE■
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.

5191-1. What to do if... (Troubleshooting)
LS500h_OM_OM50F42U_(U) 519Alphabetical Index
Preparing and checking before winter
.........................................................................309
Power easy access system ........................139
Power outlets ................................................ 353
Power rear seat ..............................................135
Power steering (Elect ric power steering
system).......................................................... 303
Warning light ...............................................430
Power switch .................................................. 168
Auto power off function .............................171
Changing the power switch modes ..170
Power switch (engine switch)
If your vehicle has to be stopped in an
emergency ................................................ 420
Power trunk opener and closer ............... 114
Power windows
Door lock linked window operation..152
Jam protection function............................. 151
Operation......................................................... 151
Window lock switch ..................................153
Pre-Collision System (PCS)
Function ..............................................209, 220
PCS OFF switch ...............................212, 222
Warning light ............................................... 433
Warning message........................... 219, 226
R
Radar cruise control (dynamic radar cruise
control with full-speed range).. 247, 250
Radiator .............................................................391
RCD (Rear camera detection) .............. 265
Warning message..................................... 278
RCD (Rear Camera Detection)
Function ...........................................................277
RCTA
Function .......................................................... 273
Warning message..................................... 274
RCTA (Rear Cross Traffic Alert) ......... 265
RCTA function ..............................................274
Rear air conditioning system .................. 333
Rear Cross Traffic Alert (RCTA) ......... 273
Rear door sunshades ..... ............................ 355 Rear Multi Operation Pa nel .................... 318
Rear seat position memory .......................143
Rear seats .........................................................135
Adjustment ..................................................... 135
Head restraints..............................................144
Rear seat position memory.....................143
Relaxation system ....................................... 138
Seat heaters ..................................................336
Seat ventilators ............................................336
Rear side marker lights
Light switch .................................................... 185
Replacing light bulbs ..................................417
Rear sunshades ............................................ 356
Rear turn signal lights
Replacing light bulbs ..................................417
Turn signal lever .......................................... 180
Rear view mirror
Inside rear view mirror ............................. 148
Outside rear view mirrors...................... 149
Rear window defogger ............................. 324
Refueling
Capacity .......................................................... 461
Fuel types ........................................................ 461
If the fuel filler do or cannot be opened
..........................................................................445
Opening the fuel tank cap ..................... 194
Regenerative braking ................................... 59
Remote Touch ................................................314
Replacing
Electronic key battery ................................413
Fuses...................................................................414
Light bulbs .......................................................417
Tires ................................................................. 405
Resetting the message indicating mainte-
nance is required ...................................... 378
Rev indicator .................................................... 83
Rev peak............................................................. 83
Road Sign Assist ...........................................247
RSA (Road Sign Assist) .............................247
Run-flat tires........................................ 397, 442