Page 546 of 784
546
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
Hybrid vehicles (2AR-FXE engine)
■12-volt battery (hybrid vehicles)
P. 5 6 2
Washer fluid tank ( P. 561)
Fuse boxes ( P. 586)
Power control unit coolant
reservoir ( P. 553)
Engine oil level dipstick (P. 548)
Engine oil filler cap (P. 550) Engine coolant reservoir
(P. 553)
Brake fluid reservoir (P. 5 5 6 )
Power control unit coolant
radiator ( P. 555)
Electric cooling fans
Condenser ( P. 555)
Engine coolant radiator (P. 555)1
2
3
4
5
6
7
8
9
10
11
Page 554 of 784

554
ES350_300h_OM_OM33B99U_(U)
7-3. 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 un it 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 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 555 of 784
ES350_300h_OM_OM33B99U_(U)
5557-3. Do-it-yourself maintenance
7
Maintenance and care
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
Radiator and condenser
CAUTION
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause serious inju-
ries, such as burns.
Page 688 of 784
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 expe rienced. (For example,
the vehicle speed does not increase.)
●Steam comes out from under the hood.
Correction procedures
1
2
3
1
2
Page 689 of 784
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 fa ns 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 engine immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
4
1
2
3
4
5
6
7
Page 690 of 784

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 temperatur e 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 692 of 784
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 693 of 784
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 fa ns 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.
6
7