Page 453 of 608

ES300h_OM_OM33D45U_(U)
4537-3. Do-it-yourself maintenance
7
Maintenance and care
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system 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. 531)
■Power control unit 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. 531)
■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 mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 °F [-35 °C])
Canada:
“Toyota Super Long Life Cool ant” is a mixture 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 c oolant reservoir cap, power control unit cool-
ant reservoir cap, drain cock and water pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.
Coolant
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454
ES300h_OM_OM33D45U_(U)7-3. Do-it-yourself maintenance
Check the radiator and condenser an
d clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine coolant reservoi r cap, power control unit coolant reservoir
cap, or the radiator cap.
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 cool-
ing. 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.
Radiator and condenser
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.
Page 510 of 608

5108-2. Steps to take in an emergency
ES300h_OM_OM33D45U_(U)
*: A buzzer sounds the first time a message is shown on the multi-information display.
■If “Hybrid System Overheated Reduced Output Power” is shown
This message may be displayed when driving under severe operating conditions.
(For example, when driving up a long steep hill.)
Handling method: →P. 531
■If “Maintenance Required for Hybrid Batter y Cooling Parts at Your Dealer” is shown
The filter may be clogged, the air intake vent may be blocked or there may be a gap in
duct. Have maintenance performed on the hy brid battery (traction battery) cooling
component at your Lexus dealer.
■If “Hybrid Battery Low Shift Out of N to Recharge” is shown
Message is displayed when the remaining char ge for the hybrid battery (traction battery)
is low.
As the hybrid battery (tractio n battery) can not be charged when the shift lever is in N,
when stopped for long periods of time shift the shift lever to P.
■If “Hybrid Battery Low Hybrid System St opped Shift to P and Restart” is shown
Message is displayed when the remaining char ge for the hybrid battery (traction battery)
is low, because vehicle has been sh ifted N for a long period of time.
When operating the vehicle, restart the hybrid system.
■If “Shift to P Before Ex iting Vehicle” is shown
Message is displayed when the driver’s door is opened without turning the power switch
to OFF with the shift lever in any position other than P.
Shift the shift lever to P.
■If “Shift Is in N Release Accelerator Before Shifting” is shown
Message is displayed when th e accelerator pedal has been depressed and the shift lever
is in N. Release the accel erator pedal and shift the shift lever to D or R.
■If “Maintenance Required Soon” is shown (U.S.A. only)
Indicates that all maintenance according to the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles (7200 km) after the message has been reset.
If necessary, perform maintenance.
*: Refer to the separate “Scheduled Maintena nce” or “Owner’s Manual Supplement” for
the maintenance interval applicable to your vehicle.
Comes on⎯Does not sound
Indicates a condition, such as malfunc-
tion of electrical components, their
condition, or indicates the need for
maintenance
Flashes⎯Does not sound
Indicates a situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly
System
warning
lightWarning buzzer*Warning
Page 531 of 608

531
ES300h_OM_OM33D45U_(U)8-2. Steps to take in an emergency
8
When trouble arises
If your vehicle overheats
■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 system, 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.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” lines on the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( →P. 86) enters the
red zone or a loss of hybrid system po wer is experienced. (For example, the
vehicle speed does not increase.)
●“Hybrid System Overheated” is shown on the multi-information display.
●Steam comes out from under the hood.
Correction procedures
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5328-2. Steps to take in an emergency
ES300h_OM_OM33D45U_(U)
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
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, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
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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Page 533 of 608
5338-2. Steps to take in an emergency
ES300h_OM_OM33D45U_(U)
8
When trouble arises
■If “Hybrid System Overheated” is shown on the multi-information display Stop the vehicle in a safe place.
Stop the hybrid system an d carefully lift the hood.
After the hybrid system has cooled down, 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 coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.
Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
Start the hybrid system and check for the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
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Page 534 of 608

5348-2. Steps to take in an emergency
ES300h_OM_OM33D45U_(U)
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 h ood, do not open the hood until the steam
has subsided. The engine compartment 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 rotating parts such as the fan, which may lead to fingers or clothing
(especially a tie, a scarf or a muffler) ge tting caught, resulting in serious injury.
●Do not loosen the radiator cap or the c oolant 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 system has cooled down sufficiently. Adding cool
coolant to a hot hybrid system too quickly can cause damage to the hybrid system.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.
Page 543 of 608
ES300h_OM_OM33D45U_(U)
5439-1. Specifications
9
Vehicle specifications
Cooling system
Capacity
Gasoline
engine7.6 qt. (7.2 L, 6.3 Imp.qt.)
Power
control unit
3.4 qt. (3.2 L, 2.8 Imp.qt.)
Coolant type
Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-sili-
cate, non-amine, non-nitrite, and non-borate cool-
ant with long-life hybrid organic acid technology
Do not use plain water alone.
Ignition system
Spark plug
MakeDENSO FK16HR-A8
Gap0.031 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system
12-volt battery
Open voltage at 68°F
(20° C):12.0 V or higher
(Voltage is checked 20 minutes after the hybrid system
and all lights are turned off.)
Charging rates5 A max.