2015 Lexus GS300h engine coolant

4206-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F00E_(EE)
XGS300h
■12-volt battery
→P. 4 2 8
Power control unit coolant
reservoir ( →P. 4 2 5 )
Engine oil level dipstick (→ P. 422)
Engine oil filler cap ( →P. 4 2 3 )
Engine coolant reservoir (→ P. 4 2 5 ) Fuse box (
→P. 4 5 3 )
Wa s h e r f l u i d t a n k ( →P. 4 2 7 )
Electric cooling fans
Condenser ( →P. 4 2 7 )
Radiator ( →P. 4 2 7 )1
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425 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F00E_(EE)
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir when the hybrid system is cold.
■Engine coolant reservoirReservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line, add coolant up to the “FULL” line.
(→ P. 5 5 6 )
■Power control unit coolant reservoir
Coolant
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XGS450hXGS300h
XGS450hXGS300h
Reservoir cap
“FULL” line
“LOW” line Reservoir cap
“F” line
“L” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. (
→P. 5 5 6 ) If the level is on or below the “L” line,
add coolant up to the “F” line.
(
→ P. 5 5 6 )
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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.

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7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
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 nor-
mal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the hybrid system
●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 any authorized Lexus dealer or repairer, or
another duly qualified an
d equipped professional as soon as possible.
Visible s ymp toms
Audible symptoms
Operational symptoms

4927-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
Indicates a malfunction in:•The ABS; or
• The brake assist system
A buzzer also sounds.
→ Immediately stop the vehicle in a safe place and
contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.
→ P. 5 5 6
Indicates a malfunction in the vehicle’s charging system.
→Immediately stop the vehicle in a safe place and
contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Wa r n i n g m e s s a g eDetails/Actions

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
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5577-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.Reservoir
“FULL”
“LOW”
Coolant inlet cap
Add coolant if necessary. ( →P. 5 6 0 )
Water can be used in an emergency if engine coolant is unavailable.
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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