Page 555 of 620

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.
Page 556 of 620

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
Page 558 of 620

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
Page 559 of 620
5597-2. 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”/“F” and “LOW”/
“L” lines on the reservoir.Reservoir
“FULL”/“F”
“LOW”/“L”
Add coolant if necessary.
Water can be used in an emergency if po wer control unit 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 any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional.
4
1
2
3
XGS450h XGS300h
5
XGS450h XGS300h
6
Page 573 of 620
573
8
8-1. Specifications
Vehicle specifications
GS450h_300h_OM_OM30F00E_(EE)
*: The fluid capacity is the quantity of reference.
If replacement is necessary, contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Electrical system
12-volt battery
Open voltage at 20 °C (68 °F):12.0 V or higher
(Voltage is checked 20 minutes after the
hybrid system and all lights are turned off.)
Charging rates5 A max.
Hybrid transmission
Fluid capacity*GS450h5.69 L (6.01 qt., 5.01 Imp.qt.)
GS300h3.80 L (4.02 qt., 3.34 Imp.qt.)
Fluid typeTo y o t a G e n u i n e AT F W S
NOTICE
■Hybrid transmission fluid type
Using transmission fluid other than “Toyota Genuine ATF WS” may cause deterioration
in shift quality and ultimately damage the transmission of your vehicle.
Page 574 of 620

5748-1. Specifications
GS450h_300h_OM_OM30F00E_(EE) Your Lexus vehicle is filled with “Toyota Genuine Differential Gear Oil” at the factory.
Use Lexus approved “Toyota Genuine Differential Gear Oil” or an equivalent of match-
ing quality to satisfy the above specification.
Please contact any authorized Lexus dealer
or repairer, or another duly qualified an d equipped professional for further details.
*: Minimum pedal clearance when depressed with a force of 500 N (51.0 kgf, 112.4 lbf)
while the hybrid system is operating.
When performing the brake pedal inspection, also be sure to check that the brake
system warning light is not illuminated when the hybrid system is operating (If the
brake system warning light is illuminated, refer to P. 476).
Differential
Oil capacity1.35 L (1.43 qt., 1.19 Imp.qt.)
Oil type and viscosityToyota Genuine Differential gear oil LT
75W-85 GL-5 or equivalent
Brakes
Pe d a l c l e a r a n c e*115 mm (4.5 in.) Min.
Pedal free play1.0 — 6.0 mm (0.04 — 0.24 in.)
Fluid typeSAE J1703 or FMVSS No. 116 DOT 3,
SAE J1704 or FMVSS No. 116 DOT 4
Steering
Free playLess than 30 mm (1.2 in.)
Page 579 of 620

579
8
8-1. Specifications
Vehicle specifications
GS450h_300h_OM_OM30F00E_(EE)
Fuel information
■Use of ethanol blended gasoline in a gasoline engine
Lexus allows the use of ethanol blended gasoline where the ethanol content is up to 10%.
Make sure that the ethanol blended gasoline to be used has a Research Octane Number
that follows the above.
■If your engine knocks
●Consult any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
●You may occasionally notice light knocking fo
r a short time while accelerating or driv-
ing uphill. This is normal and there is no need for concern.
XGS450h
EU area:
You must only use unleaded gasoline conforming to European standard
EN228.
Select unleaded gasoline with a Research Octane Number of 95 or higher
for optimum engine performance.
Except EU area:
You must only use unleaded gasoline.
Select unleaded gasoline with a Research Octane Number of 95 or higher.
XGS300h
EU area:
You must only use unleaded gasoline conforming to European standard
EN228.
Select unleaded gasoline with a Research Octane Number of 91 or higher for
optimum engine performance.
Except EU area:
You must only use unleaded gasoline.
Select unleaded gasoline with a Research Octane Number of 91 or higher for
optimum engine performance.
Page 580 of 620

5808-1. Specifications
GS450h_300h_OM_OM30F00E_(EE)
NOTICE
■Notice on fuel quality
●Do not use improper fuels. If improper fuels are used, the engine will be damaged.
●Do not use leaded gasoline.
Leaded gasoline will cause the three-way catalytic converter to lose its effectiveness
and the emission control system to function improperly.
●EU area: Bioethanol fuel sold under names such as “E50” or “E85” and fuel contain-
ing a large amount of ethanol should not be used. The use of these fuels will damage
the vehicle’s fuel system. In case of any doubt, ask any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
●Except EU area: Bioethanol fuel sold under names such as “E50” or “E85” and fuel
containing a large amount of ethanol should not be used. Your vehicle can use gaso-
line mixed with 10% max ethanol. The use of fuel with more than 10% ethanol content
(E10) will damage the vehicle’s fuel system. You must ensure that refueling is carried
out only from a source where fuel specification and quality can be guaranteed. In case
of any doubt, ask any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
●Do not use the methanol blended gasoline such as M15, M85, M100. The use of gas-
oline containing methanol may cause engine damage or failure.