Page 449 of 523

4497-2. Steps to take in an emergency
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7
When trouble arises
Exhaust hole plug
Exhaust hole
Exhaust hose
For details, consult your Lexus dealer.
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 metal 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:
A
B
C
●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.
●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 ha nds after handling
the 12-volt battery support, terminals,
and other battery-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) ma y leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
Page 450 of 523

4507-2. Steps to take in an emergency
LS500h_OM_(U)_1809
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
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 ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
The engine coolant temperature
gauge ( P.81, 85) 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 Output Power
Reduced” is shown on the
multi-information display.
Steam comes out from under the
hood.
Correction procedures
Page 451 of 523

4517-2. Steps to take in an emergency
LS500h_OM_(U)_1809
7
When trouble arises
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.452)
Water can be used in an emergency if 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 oper ate 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 Out-
put Power Reduced” 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.
A
B
A
B
C
D
Page 452 of 523

4527-2. Steps to take in an emergency
LS500h_OM_(U)_1809
3After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The 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 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.
A
B
A
B
C
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4537-2. Steps to take in an emergency
LS500h_OM_(U)_1809
7
When trouble arises
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 .
6 Add coolant through the inlet of the cap
until it is full, and then replace the
cap .
AB
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 “READY”
indicator 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 clothing (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 dama ge to the hybrid
system.
AC
A
B
B
Page 454 of 523
4547-2. Steps to take in an emergency
LS500h_OM_(U)_1809
1Stop the hybrid system. Set the
parking brake and shift the shift
position to P.
2 Remove the mud, snow or sand
from around the rear wheels.
3 Place wood, stones or some other
material under the rear wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift position to D or R and
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press the switch to turn off TRAC.
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.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure
Page 455 of 523
4557-2. Steps to take in an emergency
LS500h_OM_(U)_1809
7
When trouble arises
WARNING
■When attempting to free a stuck vehi-
cle
If you choose to push the vehicle back
and forth to free it, make sure the sur-
rounding area is clear to avoid striking
other vehicles, objects or people. The
vehicle may also lunge forward or lunge
back suddenly as it becomes free. Use
extreme caution.
■When shifting the shift position
Be careful not to shift the shift position
with the accelerator pedal depressed.
This may lead to unexpected rapid accel-
eration of the vehicle that may cause an
accident resulting in death or serious
injury.
NOTICE
■To avoid damaging the transmission
and other components
●Avoid spinning the rear wheels and
depressing the accelerator pedal
more than necessary.
●If the vehicle remains stuck even after
these procedures are performed, the
vehicle may require towing to be freed.
Page 456 of 523
4567-2. Steps to take in an emergency
LS500h_OM_(U)_1809