2018 LEXUS LS500H Owners Manual

4497-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 7
When trouble arises and fuse box cover. ( → P.385,
388)Push the tabs in and lift the lid off.
3 Open the exclusive jump starting
terminal cover.
4 Connect a positive jumper cable clamp to on your vehicle and connect the
clamp on the other end of the positive cab le to on the second vehicle. Then,
connect a negative cable clamp to on the second vehicle and connect the
clamp at the other end of the negative cable to .
Exclusive jump starting terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic point away from the exclusive jump starting
terminal and any mo ving parts as shown in the illustration
5 Start the engine of the second vehi-
cle. Increase the engine speed
slightly and maintain at that level for
approximately 5 minutes to recharge the 12-volt battery of your
vehicle. A
B
C
D
A
B
C
D

450 7-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 6 Open and close any of the doors of
your vehicle with the power switch
off.
7 Maintain the engine speed of the
second vehicle and start the hybrid
system of your vehicle by turning
the power switch to ON mode.
8 Make sure the “READY” indicator
comes on. If the indicator does not
come on, contact your Lexus
dealer.
9 Once the hybrid system has
started, remove the jumper cables
in the exact reverse order from
which they were connected.
10 Close the exclusive jump starting
terminal cover and install the fuse
box cover and en gine compart-
ment cover.
Once the hybrid system starts, have
the vehicle inspected at your Lexus
dealer as soon as possible. ■
Starting the hybrid system when the
12-volt battery is discharged
The hybrid system cannot be started by
push-starting. ■
To prevent 12-volt battery discharge●
Turn off the headlights and the audio sys-
tem while the hybrid system is off.
●
Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■
When the 12-volt battery is removed or
discharged
●
Information stored in the ECU is cleared.
When the 12-volt battery is depleted,
have the vehicle inspected at your Lexus
dealer.
●
Some systems may require initialization. ( → P.495)■
When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the
12-volt battery terminals, contact your
Lexus dealer. ■
Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradually even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.) ■
When recharging or replacing the
12-volt battery ●
In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
12-volt battery is discharged. Use the
wireless remote control or the mechani-
cal key to lock or unlock the doors. ●
The hybrid system may not start on the
first attempt after the 12-volt battery has
recharged but will start normally after the
second attempt. This is not a malfunction. ●
The power switch mode is memorized by
the vehicle. When the 12-volt battery is
reconnected, the system will return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
the 12-volt battery, turn the power switch
off.
If you are unsure what mode the power
switch was in before the 12-volt battery
discharged, be especially careful when
reconnecting the 12-volt battery.
■
When replacing the 12-volt battery
●
Use a Central Degassing type 12-volt
battery (European Regulations).
●
Use a 12-volt battery with the same case
size as the previous 12-volt battery and an
epuivalent 20 hour rate capacity (20HR)
or greater.

4517-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 7
When trouble arises • If the sizes differ, the 12-volt battery can-
not be properly secured.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and the hybrid system
may not be able to start.●
Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.●
After replacing, firmly attach the follow-
ing items to the exhaust hole of the
12-volt battery.
• Use the exhaust hose that was attached
to the 12-volt battery before replacing
and confirm that it is firmly connected to
the hole section of the vehicle.
• Use the exhaust hole plug included with
the 12-volt battery replaced or the one
installed on the 12-volt battery prior to
the replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose
For details, consult your Lexus dealer. A
B
C WARNING■
When removing the 12-volt battery
terminals
Always remove the negative (-) terminal
first. If the positive (+) terminal contacts
any metal in the surrounding area when
the positive (+) terminal is removed, a
spark may occur, leading to a fire in addi-
tion to electrical shocks and death or
serious injury. ■
Avoiding 12-volt battery fires or
explosions
Observe the following precautions to
prevent accidentally igniting the flamma-
ble gas that may be emitted from the
12-volt battery: ●
Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentiona lly in contact with
any other than the intended terminal. ●
Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or meta l surfaces in the
area, such as brackets or unpainted
metal. ●
Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●
Do not smoke, use matches, cigarette
lighters or allow open flame near the
12-volt battery.
■
12-volt battery precautions
The 12-volt battery contains poisonous
and corrosive acidic electrolyte, while
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
●
When working with the 12-volt battery,
always wear safety glasses and take
care not to allow any battery fluids
(acid) to come into contact with skin,
clothing or the vehicle body.
●
Do not lean over the 12-volt battery.

452 7-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) WARNING●
In the event that battery fluid comes
into contact with the skin or eyes,
immediately wash the affected area
with water and seek medical attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.●
Always wash your hands after handling
the 12-volt battery support, terminals,
and other batter y-related parts.●
Do not allow children near the 12-volt
battery.■
After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers. ■
When replacing the 12-volt battery●
When the vent plug and indicator are
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.●
For information regarding 12-volt bat-
tery replacement, contact your Lexus
dealer.
●
After replacing, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the replaced
12-volt battery. If not properly installed,
gases (hydrogen) may leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
NOTICE
■
When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fan or engine drive
belt. ■
To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another vehicle in an emer-
gency. It cannot be used to jump start
another vehicle.

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

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.