cooling Lexus GS300h 2015 User Guide

4266-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F00E_(EE)
■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% deionized water.
(Minimum temperature: -35 °C [-31 °F])
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 radiator, 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 sys-
tem.
WA R N I N G
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the coolant
inlet cap. ( →P. 5 6 1 )
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.

5087-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
Carrying out the corresponding action turns the messages off.
Other displayed messages
Wa r n i n g m e s s a g eDetails/Actions
Maintenance of the hybrid battery (traction battery)
cooling component is requiredThe filter may be clogged, the air intake vent may be
blocked or there may be a gap in the duct.
→ Have maintenance performed on the hybrid battery
(traction battery) cooling component at any autho-
rized Lexus dealer or repairer, or another duly qual-
ified and equipped professional.

5557-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
WA R N I N G
■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 precautions when han-
dling 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, clothing 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, immedi-
ately 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 any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional 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. 4 3 0
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in the
cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It cannot be used to jump start another vehicle.

5567-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( →P. 104) enters the
red zone or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” ( →P. 482) 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
or “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display
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 any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2

5587-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
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 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 any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
If the fans are operating:
Have the vehicle inspected at the nearest any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■If “Hybrid System Overheated Reduced Output Power” is shown on the
multi-information displayStop 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 radiator
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
6
7
1
2
3
1
2

5617-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
WA R N I N G
■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 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 coolant inlet cap or the
coolant reservoir caps while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.XGS450h
XGS300h

5627-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
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 foreign matter (such as sand or dust etc.).
●Do not use any coolant additive.

5728-1. Specifications
GS450h_300h_OM_OM30F00E_(EE)
Cooling system
Gasoline engine
Power control unit
Left-hand drive vehiclesRight-hand drive vehicles
Capacity
GS450h9.2 L (9.7qt.,
8.1 Imp.qt.)2.1 L (2.2qt.,
1.8 Imp.qt.)1.9 L (2.0qt.,
1.7 Imp.qt.)
GS300h8.1 L (8.6 qt.,
7.1 Imp.qt.)1.6 L (1.7 qt.,
1.4 Imp.qt.)1.8 L (1.9 qt.,
1.6 Imp.qt.)
Coolant typeUse 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
Make
GapDENSO FK20HBR8
0.8 mm (0.031 in.)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.

604Alphabetical index
GS450h_300h_OM_OM30F00E_(EE)
Cargo hooks........................................... 394
CD player
*
Chains .......................................................355
Child restraint system ............................ 56Baby seats, definition .......................... 57
Baby seats, installation ....................... 66
Child seats, definition.......................... 57
Child seats, installation....................... 66
Installing CRS with ISOFIX rigid anchors........................................ 69
Installing CRS with seat belts.......... 66
Installing CRS with top strap .......... 70
Junior seats, definition ........................ 57
Junior seats, installation .....................68
Child safety................................................. 55 12-volt battery
precautions........................... 430, 555
Airbag precautions .............................. 45
Child restraint system......................... 56
How your child should
wear the seat belt ..................... 39, 40
Installing child restraints .................... 65
Moon roof precautions ................... 198
Power window lock switch.............193
Power window precautions .......... 195
Rear door child-protectors ............143
Removed electronic key battery precautions ....................... 452
Seat belt comfort guide ..................... 39
Seat belt precautions .......................... 42
Seat heater precautions .................. 381
Trunk precautions ..............................149
Child-protectors ................................... 143 Cleaning.........................................406, 410
Aluminum wheels.............................. 407
Exterior ................................................... 406
Interior.......................................................410
Seat belts ................................................... 411
Clock ...............................................105, 398
Coat hooks.............................................. 402
Condenser ..............................................427
Console box ........................................... 390
Console box light ...................................391
Coolant..................................................... 425 Capacity..................................................572
Checking ............................................... 425
Preparing and checking
before winter.................................... 354
Cooling system ..................................... 425
Engine overheating .......................... 556
Hybrid system overheating.......... 556
Consumption screen ........................... 126
Cruise control Cruise control ......................................327
Dynamic radar cruise control ....... 315
Dynamic radar cruise control with full-speed range ................... 303
Cup holders ..............................................391
Curtain shield airbags .......................... 43
Customizable features........................ 581