2018 LEXUS LS500H radiator

380 6-2. Maintenance
LS500h_OM_OM50F42U_(U) Radiator/con-
denser The radiator and con-
denser should be free
from foreign objects.
( → P.391)
Washer fluid Is there sufficient
washer fluid?
( → P.392)
Trunk Items Check points
12-volt battery Check the connec-
tions. ( → P.393)
Vehicle interior Items Check points
Accelerator
pedal • The accelerator
pedal should move
smoothly (without
uneven pedal effort
or catching).
Hybrid transmis-
sion “Park” mech-
anism •When parked on a
slope and the shift
position is in P, is the
vehicle securely
stopped?
Brake pedal • Does the brake
pedal move
smoothly?
• Does the brake
pedal have appro-
priate clearance
from the floor?
• Does the brake
pedal have the cor-
rect amount of free
play? Items Check points
Brakes • The vehicle should
not pull to one side
when the brakes are
applied.
•The brakes should
work effectively.
• The brake pedal
should not feel
spongy.
• The brake pedal
should not get too
close to the floor
when the brakes are
applied.
Head restraints •Do the head
restraints move
smoothly and lock
securely?
Indicators/buzz-
ers •Do the indicators
and buzzers function
properly?
Lights • Do all the lights
come on?
Parking brake • Does the parking
brake operate nor-
mally?
• When parked on a
slope and the park-
ing brake is on, is the
vehicle securely
stopped?
Seat belts • Do the seat belts
operate smoothly?
• The seat belts should
not be damaged.Items Check points

3836-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care 6-3.Do-it-yourself maintenance
Do-it-yourself service pre-
cautions If you perform maintenance by
yourself, be sure to follow the cor-
rect procedure as given in these
sections.
Maintenance Items Parts and tools
12-volt battery
condition
( → P.393) •Grease
• Conventional
wrench (for terminal
clamp bolts)
Brake fluid level
( → P.391) • FMVSS No.116 DOT
3 or SAE J1703
brake fluid
FMVSS No.116 DOT
4 or SAE J1704
brake fluid
•Rag or paper towel
• Funnel (used only for
adding brake fluid) Engine/power
control unit cool-
ant level
( → P.390) •“Toyota Super Long
Life Coolant” or a
similar high quality
ethylene gly-
col-based non-sili-
cate, non-amine,
non-nitrite and
non-borate coolant
with long-life hybrid
organic acid tech-
nology
For the U.S.A.:
“Toyota Super Long
Life Coolant” is
pre-mixed with 50%
coolant and 50%
deionized water.
For Canada:
“Toyota Super Long
Life Coolant” is
pre-mixed with 55%
coolant and 45%
deionized water.
•Funnel (used only for
adding coolant)
Engine oil level
( → P.388) •“Toyota Genuine
Motor Oil” or equiv-
alent
• Rag or paper towel
•Funnel (used only for
adding engine oil)
Fuses ( → P.414) •Fuse with same
amperage rating as
original
Radiator and con-
denser ( → P.391) ⎯Items Parts and tools

384 6-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) Tire inflation pres-
sure ( → P.408) • Tire pressure gauge
•Compressed air
source
Washer fluid
( → P.392) • Water or washer
fluid containing anti-
freeze (for winter
use)
• Funnel (used only for
adding water or
washer fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions. ■
When working on the engine com-
partment●
Make sure that the “ACCESSORY” or
“IGNITION ON” on the multi-infor-
mation display and the “READY” indi-
cator are both off.●
Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●
Be careful not to touch the engine,
power control unit, radiator, exhaust
manifold, etc. right after driving as they
may be hot. Oil and other fluids may
also be hot.
●
Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●
Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable. Items Parts and tools ■
When working near the electric cool-
ing fan or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the
electric cooling fan may automatically
start to run if the air conditioning is on
and/or the coolant temperature is high.
( → P.391) ■
Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE■
If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

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

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.