Page 459 of 628

4457-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -35C [-31F])
For more details about coolant, contact any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional.
If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional, test the cap and check for leaks
in the cooling system.
CAUTION
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water
filler cap. (P. 558)
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 pro-
tection 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 536 of 628

5228-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Indicates a malfunction in:
• The automatic headlight leveling system; or
• The Automatic High Beam system (if equipped)
• The LED headlight system (if equipped)
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
Indicates that the accelerator and brake pedal are
being depressed simultaneously
Release the accelerator or brake pedal.
Indicates that the cooling performance of the hybrid
battery (traction battery) has dropped
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied and equipped professional.
Indicates that the washer fluid level is low
Add washer fluid.
Indicates that remaining fuel is approximately 10 L
(2.6 gal., 2.2 Imp. gal.) or less
Refuel the vehicle.
Indicates that the TRC (Traction Control) system
has been deactivated
Turn the TRC on. (P. 295)
(If equipped)
Indicates that all maintenance is required to corre-
spond to the driven distance on the maintenance
schedule
*1.
Comes on approximately 10000 km (6214 miles)
after the maintenance data has been reset.
(The indicator will not work properly unless the
maintenance data has been reset.)
Perform the necessary maintenance. Please reset
the maintenance data after the maintenance is
performed (P. 442)
Warning messageDetails/Actions
(Flashes)
Page 569 of 628
5558-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
NOTICE
When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled
in the cooling fans or belt.
Exclusive jump starting terminal
The exclusive jump starting terminal is intended to charge the 12-volt battery
on your vehicle from another vehicle in an emergency. Do not use the exclusive
jump starting terminal to jump start another vehicle.
Page 570 of 628

5568-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
The needle of the engine coolant temperature gauge (P. 110) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
“Hybrid System Overheat” is shown on the multi-information display.
Steam comes out from under the hood.
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.
After the hybrid system 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 any
authorized Lexus dealer or
repairer, or another duly quali-
fied and equipped professional.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
Page 571 of 628

5578-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
The coolant level is satisfac-
tory 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 emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for coolant
leaks from the radiator or hoses.
The fan operates when the air conditioning system is turned on immedi-
ately 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 conditioning
system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the hybrid system immediately and contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional.
If the fan is operating:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
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.
4
1
2
3
5
6
7
1
2
Page 572 of 628
5588-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
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 any
authorized Lexus dealer or
repairer, or another duly quali-
fied and equipped professional.
The coolant level is satisfac-
tory if it is between the “F”
and “L” lines on the reservoir.
Reservoir
“F”
“L”
Add coolant if necessary.
Water can be used in an emer-
gency 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 any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
If the message is not displayed:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
3
1
2
4
1
2
3
5
6
Page 573 of 628

5598-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
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.
After the hybrid system has been turned off, check that the “READY” indica-
tor is off.
When the hybrid system 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 belt and fan, which
may lead to fingers or clothing (especially a tie, a scarf or a muffler) getting
caught, resulting in serious injury.
NOTICE
When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Add-
ing 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 foreign matter (such as sand or dust
etc.).
When using coolant additives, use genuine Toyota products or equivalent.
Do not loosen the coolant reservoir caps
or water filler cap while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.
Page 582 of 628
567
9 9-1. Specifications
Vehicle specifications
IS300h_EE(OM53B95E)
Spark plug
Cooling system
Gasoline engine
Power control unit
Left-hand drive
vehiclesRight-hand drive
vehicles
Capacity8.2 L (8.7 qt.,
7.2 Imp. qt.)2.0 L (2.1 qt.,
1.8 Imp. qt.)2.2 L (2.3 qt.,
1.9 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 coolant
with long-life hybrid organic acid technology
Do not use plain water alone.
Ignition system
Make DENSO FK20HBR8
Gap 0.8 mm (0.031 in.)
NOTICE
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.