Page 689 of 787

6878-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
8
When trouble arises
CAUTION
■Avoiding 12-volt battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable
gas that may be emitted from the 12-volt battery:
●Make sure each jumper cable is connected to the correct terminal and that it is
not unintentionally in contact with any other than the intended terminal.
●Do not allow the other end of the jumper cable connected to the “+” terminal 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 compounds. 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 12-volt battery fluids (acid) to come into contact with skin, cloth-
ing or the vehicle body.
●Do not lean over the 12-volt battery.
●In the event that 12-volt 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 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, continued 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
→P. 5 6 5
Page 690 of 787
688
ES350_300h_OM_OM33B99U_(U)
8-2. Steps to take in an emergency
If your vehicle overheats (gasoline vehicles)
Stop the vehicle in a safe place and turn off the air conditioning system,
and then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and
radiator core (radiator) for any leaks.Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( →P. 97) enters
the red zone or a loss of engine power is experienced. (For example,
the vehicle speed does not increase.)
●Steam comes out from under the hood.
Correction procedures
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2
3
1
2
Page 691 of 787
6898-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
8
When trouble arises
The coolant level is satisfactory if it is between the “FULL” and “LOW”
line on the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that
the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately after
a cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, turn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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Page 692 of 787

6908-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
CAUTION
■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 compartment may be very hot.
●Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans
and belts. Failure to do so may cause the hands or clothing to be caught, resulting
in serious injury.
●Do not loosen the radiator cap or the coolant reservoir cap while the engine and
radiator are hot. High temperature steam or coolant could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can cause damage to the engine.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additives.
Page 693 of 787
691
ES350_300h_OM_OM33B99U_(U)
8-2. Steps to take in an emergency
8
When trouble arises
If your vehicle overheats (hybrid vehicles)
■If the needle of the engine coolant temperature gauge enters the red
zone
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( →P. 97) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
●“Hybrid System Overheat” ( →P. 647) is shown on the multi-informa-
tion display.
●Steam comes out from under the hood.
Correction procedures
1
2
Page 694 of 787
6928-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
After the hybrid system has cooled down sufficiently, inspect the
hoses and cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
The coolant level is satisfactory if it is between the “FULL” and
“LOW” line on the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
3
1
2
4
1
2
3
4
5
Page 695 of 787
6938-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
8
When trouble arises
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fans operate and to check for coolant
leaks from the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately
after a cold start. Confirm that the fans are operating by checking the fan
sound and air flow. If it is difficult to check these, turn the air conditioning sys-
tem on and off repeatedly. (The fans may not operate in freezing tempera-
tures.)
If the fans are not operating:
Stop the hybrid system immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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7
Page 696 of 787
6948-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
■If “Hybrid System Overheat” is shown on the multi-information dis-
play
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, inspect the hoses and radi-
ator core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
The coolant level is satisfactory if it is between the “FULL” and
“LOW” line on the reservoir.Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
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2
3
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