2018 LEXUS LS500H cooling

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

454 7-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) coolant is unavailable.
6 Start 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
Reduced Output Power” 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 “F” and “L” lines on
the reservoir.
Reservoir
“F” line
“L” line
5 Remove the engine compartment
cover and add coolant if necessary. Water can be used in an emergency if A
B
A
B
C

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.

4638-1. Specifications
LS500h_OM_OM50F42U_(U) 8
Vehicle specifications Outside temperature
Oil viscosity (0W-20 is explained here
as an example):
• The 0W in 0W-20 indicates the
characteristic of the oil which allows
cold startability. Oils with a lower
value before the W allow for easier
starting of the engine in cold
weather.
• The 20 in 0W-20 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:
The International Lubricant Specifica-
tion Advisory Committee (ILSAC)
Certification Mark is added to some oil
containers to help you select the oil you
should use.A
Cooling system Capacity Gasoline
engine 11.6 qt. (11.0 L, 9.7 Imp. qt.)
Power con-
trol unit 2.6 qt. (2.5 L, 2.2 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 orga nic acid technology
Do not use plain water alone.
Ignition system (spark plug) Make DENSO FK20HBR8
Gap 0.031 in. (0.8 mm)

512 Alphabetical Index
LS500h_OM_OM50F42U_(U) C
Card key .......................................................... 104
Care
Aluminum wheels ...................................... 370
Exterior ........................................................... 370
Interior ............................................................. 373
Seat belts........................................................ 373
Cargo capacity...............................................166
Cargo net ....................................................... 348
Center Display ...............................................316
Chains ............................................................... 310
Child restraint system
Fixed with a LATCH system .................. 53
Fixed with a seat belt................................... 49
Front passenger occupa nt classification
system ............................................................. 40
Points to remember .................................... 45
Riding with children ..................................... 45
Types of child restraint system installation
method ........................................................... 46
Using an anchor bracket .......................... 55
Child safety
12-volt battery precautions ........ 394, 451
Airbag precautions...................................... 34
Child restraint system................................. 46
Heated steering wheel and seat heater
precautions................................................ 337
How your child should wear the seat belt
............................................................................ 25
Moon roof precautions ............................154
Power window lock switch.....................153
Power window precautions ...................152
Rear door child-protectors ....................... 111
Removed electronic key battery precau-
tions ................................................................. 414
Seat belt extender precautions ............. 25
Seat belt precautions .................................. 45
Trunk precautions .........................................112
Child-protectors...............................................111
Cleaning
Aluminum wheels ...................................... 370 Exterior............................................................370
Interior ............................................................. 373
Radar sensor ........................ 199, 200, 206
Seat belts ........................................................ 373
Clock ................................................. 77, 81, 353
Clock light ...................................................... 340
Coat hooks..................................................... 352
Coin holder .................................................... 345
Condenser .......................................................391
Console box .................................................. 346
Cooling system............................................. 390
Engine overheating...................................453
Hybrid system overheating ..................454
Cornering lights .............................................187
Cruise control
Dynamic radar cruise control with
full-speed range ..........................247, 250
Cup holders ................................................... 345
Current fuel consumption .......................... 88
Curtain shield airbags .................................. 29
Customizable features ............................... 481
D
Daytime running light system .................. 185
Defogger
Outside rear view mirrors..................... 324
Rear window ................................................ 324
Windshield .................................................... 324
Differential
Front differential oi l............. ...................... 465
Rear differential oil......... .......... ........... ...... 465
Dimension ...................................................... 460
Dinghy towing................................................. 167
Display
Center Display ............................................. 316
Dynamic radar cruise control with
full-speed range ..................................... 250
Energy monitor .............................................. 96
Head-up display............................................ 92
Intuitive parking assist ..............................266
LKA (Lane-Keeping Assist) ................. 243
LTA (Lane-Tracing Assist) ................... 234