2018 LEXUS LS500H coolant temperature

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

426 7-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U)  Fluid leaks under the vehicle.
(Water dripping from the air condi-
tioning after use is normal.)
 Flat-looking tires or uneven tire
wear
 Engine coolant temperature gauge
needle continually points higher
than normal.
 Changes in exhaust sound
 Excessive tire squeal when corner-
ing
 Strange noises related to the sus-
pension system
 Pinging or other noises related to
the hybrid system
 Engine missing, stumbling or run-
ning roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking  Vehicle pulls heavily to one side
when driving on a level road
 Loss of brake effectiveness, spongy
feeling, pedal almost touches the
floor
If you think something is
wrong If you notice any of the following
symptoms, your vehicle probably
needs adjustment or repair. Con-
tact your Lexus dealer as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms

4277-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 7
When trouble arises ■
Brake system warning light (warning buzzer)
■
Brake system warning light (warning buzzer)
■
High coolant temperature warning light *
(warning buzzer)
*
: This light illuminates on the multi-information display.If a warning light turns on or a warning buzzer soundsCalmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Actions to the warning lights or warning buzzers Warning light Details/Actions(U.S.A.)
or (red)
(Canada) Indicates that:
 The brake fluid level is low; or
 The brake system is malfunctioning
→ Immediately stop the vehicle in a safe place and contact your Lexus
dealer. Continuing to drive the vehicle may be dangerous.
Indicates that the brake pads are worn out (only the right-side pads can
be detected)
→ Have the vehicle inspected by your Lexus dealer.
Warning light Details/Actions
(yellow) Indicates a malfunction in:
 The regenerative braking system;
 The electronically controlled brake system; or
 The parking brake system
→ Have the vehicle inspected by your Lexus dealer immediately.
Warning light Details/Actions
Indicates that the engine coolant temperature is too high
→ Immediately stop the vehicle in a safe place.
Handling method ( → P.453)

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

4557-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 7
When trouble arises coolant is unavailable.
6 After stopping the hybrid system
and waiting for 5 minutes or more,
start the hybrid system again and
check for 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 message appears again fre-
quently, contact your Lexus dealer.
■
When adding engine coolant
Add coolant in accordance with the follow-
ing procedure.
1 Remove the engine compartment
cover. 2 Push the tab in and open the engine
compartment cover.
3 Remove the engine cover.
4 Remove the caps and .
5 Add coolant through the inlet of the cap
up to the “F” line , and then
replace the cap . A B
A C
A

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)

514 Alphabetical Index
LS500h_OM_OM50F42U_(U) emergency ................................................ 420
If your vehicle needs to be towed ..... 422
If your vehicle overheats ........................ 453
Energy monitor ....................................... 96, 97
Engine
ACCESSORY mode ...............................170
Compartment ............................................. 387
Engine compartment cover ................ 388
Engine switch................................................ 168
Hood............................................................... 385
How to start the hybrid system ........... 168
Identification number .................................461
If the hybrid system will not start ........ 443
If your vehicle has to be stopped in an
emergency ................................................ 420
Ignition switch (power switch) ............. 168
Overheating................................................. 453
Power switch ................................................ 168
Tachometer .............................................. 77, 81
Engine compartment cover ....................388
Engine coolant
Capacity ......................................................... 463
Checking .......................................................390
Preparing and checking before winter
.........................................................................309
Engine coolant temperature gauge .77, 81
Engine oil
Capacity ......................................................... 462
Checking ...................................................... 388
Preparing and checking before winter
.........................................................................309
Warning light ............................................... 428
Engine oil maintenance data .................. 390
Engine switch (power switch) ................. 168
If your vehicle has to be stopped in an
emergency ................................................ 420
EPS (Electric Power Steering) .............. 303
Warning light ...............................................430
EV drive mode................................................ 172
EV indicator ...................................................... 59
Event data recorder (EDR) ............................7 F
FCTA (Front Cross Traffic Alert) ..........227
First-aid kit storage belt ............................ 349
Flat tire
Tire pressure warning system ............. 397
Floor mats ...........................................................22
Fluid
Brake ............................................................... 465
Hybrid transmission..................................464
Washer ............................................................ 391
Footwell light ................................................. 340
Front air conditioning system ................. 323
Front Cross Traffic Alert (FCTA) ..........227
Front passenger occupant classification
system .............................................................. 40
Front seats
Adjustment ..................................................... 128
Cleaning ......................................................... 373
Correct driving posture ............................ 23
Driving position memory ........................ 139
Head restraints..............................................144
Memory recall function.............................142
Power easy access system .................... 139
Refresh system ............................................. 133
Seat heaters ..................................................336
Seat position memory .............................. 139
Seat ventilators ............................................336
Front side marker light
Light switch .................................................... 185
Replacing light bulbs ..................................417
Front turn signal lights
Replacing light bulbs ..................................417
Turn signal lever .......................................... 180
Fuel
Capacity .......................................................... 461
Fuel gauge ................................................. 77, 81
Information ....................................................470
Refueling.......................................................... 194
Type ................................................................... 461
Warning light .............................................. 430