2013 Lexus GS300h cooling

9187-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
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”
Coolant inlet cap
3
1
2
GS300hGS450h
4
1
2
3
4
GS300hGS450h

9197-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
Add coolant if necessary. (P. 923)
Water can be used in an emergency if engine 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 immedi-
ately 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 your Lexus
dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
5
GS300hGS450h
6
7

9207-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
If “Hybrid System Overheat” is shown on the multi-information
display
Stop 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 your Lexus
dealer.
The coolant level is satisfactory if it is between the “F”/
“FULL” and “L”/“LOW” lines on the reservoir.
Reservoir
“F”/“FULL”
“L”/“LOW”
1
2
3
1
2
GS300hGS450h
4
1
2
3
GS300hGS450h

9247-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
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 indicator on
the power switch and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automati-
cally 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 muf-
fler) getting caught, resulting in serious injury.
Do not loosen the coolant inlet cap or
the coolant reservoir caps while the
hybrid system and radiator are hot.
High temperature steam or coolant
could spray out.

9257-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30D53E_(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 additives.

933
8 8-1. Specifications
Vehicle specifications
GS450h_300h_OM_OM30D53E_(EE)
Cooling system
Gasoline
engine
Power control unit
Left-hand
drive
vehiclesRight-hand
drive
vehicles
Capacity
GS300h8.4 L (8.9 qt.,
7.4 Imp.qt.)2.1 L (2.2 qt.,
1.8 Imp.qt.)2.3 L (2.4 qt.,
2.0 Imp.qt.)
GS450h9.4 L (9.9 qt.,
8.3 Imp.qt.)3.1 L (3.3 qt.,
2.7 Imp.qt.)2.9 L (3.1 qt.,
2.6 Imp.qt.)
Coolant typeUse either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and
non-borate coolant 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.

965Alphabetical index
GS450h_300h_OM_OM30D53E_(EE)
Child safety .................................58
12-volt battery
precautions .................752, 916
Airbag precautions..................47
Child restraint system .............59
How your child should
wear the seat belt ............39, 41
Installing child restraints ........71
Moon roof precautions .........221
Power window lock switch...215
Power window precautions...217
Rear door child-protectors ....184
Removed electronic key
battery precautions .............781
Seat belt comfort guide...........39
Seat belt precautions ...............43
Seat heater precautions .........703
Trunk precautions ................190
Child-protectors ........................184
Cleaning ............................720, 724
Aluminum wheels.................721
Exterior .................................720
Interior ..................................724
Seat belts...............................725Clock ........................................ 698
Coat hooks ................................ 715
Condenser ................................ 747
Console box .............................. 690
Console box light...................... 690
Coolant ..................................... 744
Capacity ............................... 933
Checking .............................. 744
Preparing and checking
before winter ..................... 434
Cooling system ......................... 744
Engine overheating .............. 917
Hybrid system overheating .. 917
Cruise control
Cruise control ...................... 298
Dynamic radar cruise control ....
302
Dynamic radar cruise control
with full-speed range ......... 319
Cup holders............................... 691
Curtain shield airbags ................ 45
Customizable features .............. 943