Page 681 of 908
ES350 300h_OM_OM33A01U_(U)
6816-3. Do-it-yourself maintenance
6
Maintenance and care
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the engine is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 8 1 3 , 8 1 6 )
■Power control unit coolant reservoir (hybrid vehicles)
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 8 1 6 )
Coolant
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3
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682
ES350 300h_OM_OM33A01U_(U)
6-3. Do-it-yourself maintenance
■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 mixture of 50% coolant and 50% deionized
water. (Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 F [-42C])
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.
CAUTION
■When the engine is hot
Do not remove the engine/power control unit coolant reservoir caps.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither 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 prevent it from damaging parts or paint.
Page 749 of 908
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ES350 300h_OM_OM33A01U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If you think something is wrong
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning 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 cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the engine
●Engine missing, stumbling or running 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 notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Lexus dealer as soon as pos-
sible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 813 of 908

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7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats (gasoline vehicles)
Follow the correction procedure as described below.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 (radia-
tor) for any leaks.
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 cap
“FULL”
“LOW”
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 9 3 )
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.
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Page 814 of 908

8147-2. Steps to take in an emergency
ES350 300h_OM_OM33A01U_(U)
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 fan operates and to chec k 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, tu rn the air conditioning system on and off
repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the engine immediately and contact your Lexus dealer.
If the fan is operating:
Have the vehicle inspected at the nearest Lexus dealer.
5
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 fan
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 while the engine and radiator are hot.
High temperature steam or coolant could spray out.
6
7
Page 815 of 908
8157-2. Steps to take in an emergency
ES350 300h_OM_OM33A01U_(U)
7
When trouble arises
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 commercially available coolant additives.
Page 816 of 908
816
ES350 300h_OM_OM33A01U_(U)
7-2. Steps to take in an emergency
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 an d 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.
After the hybrid system has
cooled down sufficiently,
inspect the hoses and cooling
system for leaks.
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. 9 3 )
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. 772) is shown on the multi-informa-
tion display.
●Steam comes out from under the hood.
Correction procedures
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2
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Page 819 of 908

8197-2. Steps to take in an emergency
ES350 300h_OM_OM33A01U_(U)
7
When trouble arises
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.
●Check that the indicator on the “POWER ” switch and the “READY” indicator are
off.
●On hybrid vehicles, the gasoline engine may automatically start, or the cooling
fan may suddenly operate even if the gasoline engine stops. Do not touch or
approach rotating 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 radiator cap while th e 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 syst em has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too quickly can cause da mage to the hybrid
system.
■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 commercially available coolant additives.