2017 Lexus GS300h ECU

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1-2. Hybrid system
1
GS450h_300h_OM_OM30F92E_(EE)
For safety and security
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration ev en though the vehicle is able to move with
the “READY” indicator is illuminated. For sa fety, apply the parking brake and make sure
to shift the shift lever to P when parked.
The following sounds or vibrations may occu r when the hybrid system is operating and
are not a malfunction:
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear seats
when the hybrid system starts or stops.
●Relay operating sounds such as a snap or so ft clank will be emitted from the hybrid bat-
tery (traction battery), behind the rear se ats, when the hybrid system is started or
stopped.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the transmission when the gasoline engine starts or stops,
when driving at low speeds, or during idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is depressed
or as the accelerator pedal is released.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents on the both sides of the rear
seatback.
■Maintenance, repair, recycling, and disposal
Contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer regarding maintenance, repair, recy cling and disposal. Do not dispose of the
vehicle yourself.
■Customization
Settings (e.g. on/off operation of the EV indicator) can be changed.
(Customizable features: P. 561)

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1-2. Hybrid system
1
GS450h_300h_OM_OM30F92E_(EE)
For safety and security
There are air intake vents on the both
sides of the rear seatback for the pur-
pose of cooling the hybrid battery
(traction battery). If the vents become
blocked, the hybrid battery may over-
heat, leading to a reduction in hybrid
battery output.
When a certain level of impact is detected by the impact sensor, the emergency
shut off system blocks the high voltage current and stops the fuel pump to mini-
mize the risk of electrocution and fuel leakage. If the emergency shut off system
activates, your vehicle will not restart. To restart the hybrid system, contact any
authorized Lexus retailer or Lexus authorized repairer, or any reliable repa irer.
A message is automatically displayed when a malfunction occurs in the hybrid
system or an improper operation is attempted.
If a warning message is shown on the
multi-information display, read the
message and follow the instructions. (  P. 466)
Hybrid battery (traction battery) air intake vents
Emergency shut off system
Hybrid warning message

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1-2. Hybrid system
1
GS450h_300h_OM_OM30F92E_(EE)
For safety and security
WARNING
■Road accident cautions
Observe the following precautions to reduce the risk of death or serious injury:
●Pull your vehicle off the road, apply the parking brake, shift the shift lever to P, and
turn the hybrid system off.
●Do not touch the high voltage parts, cables and connectors.
●If electric wires are exposed inside or outside your vehicle, an electric shock may
occur. Never touch exposed electric wires.
●If a fluid leak occurs, do not touch the fluid as it may be strong alkaline electrolyte
from the hybrid battery (traction battery). If it comes into contact with your skin or
eyes, wash it off immediately with a large amount of water or, if possible, boric acid
solution. Seek immediate medical attention.
●If a fire occurs in the hybrid vehicle, leave the vehicle as soon as possible. Never use a
fire extinguisher that is not meant for electric fires. Using even a small amount of
water may be dangerous.
●If your vehicle needs to be towed, do so with rear wheels raised. If the wheels con-
nected to the electric motor (traction motor) are on the ground when towing, the
motor may continue to generate electricity. This may cause a fire. ( P. 454)
●Carefully inspect the ground under the vehicl e. If you find that liquid has leaked onto
the ground, the fuel system may have been damaged. Leave the vehicle as soon as possible.

85
1
1-3. Theft deterrent system
GS450h_300h_OM_OM30F92E_(EE)
For safety and security
Immobilizer system
The indicator light flashes after the
power switch has been turned off to
indicate that the system is operating.
The indicator light stops flashing after
the power switch has been turned to
ACCESSORY or ON mode to indi-
cate that the system has been canceled.
■System maintenance
The vehicle has a maintenance-free type immobilizer system.
■Conditions that may cause the system to malfunction
●If the grip portion of the key is in contact with a metallic object
●If the key is in close proximity to or touching a key to the security system (key with a
built-in transponder chip) of another vehicle
The vehicle’s keys have built-in transpon der chips that prevent the hybrid sys-
tem from starting if a key has not been previously registered in the vehicle’s
on-board computer.
Never leave the keys inside the vehicle when you leave the vehicle.
This system is designed to help prev ent vehicle theft but does not guarantee
absolute security against all vehicle thefts.

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1-3. Theft deterrent system
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GS450h_300h_OM_OM30F92E_(EE)
For safety and security

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1-3. Theft deterrent system
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GS450h_300h_OM_OM30F92E_(EE)
For safety and security
NOTICE
■To ensure the system operates correctly
Do not modify or remove the system. If mo dified or removed, the proper operation of
the system cannot be guaranteed.

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1
1-3. Theft deterrent system
GS450h_300h_OM_OM30F92E_(EE)
For safety and security
Alarm 
The alarm uses light and sound to give an
alert when an intrusion is detected.
The alarm is triggered in the following situations when the alarm is set: ● A locked door is unlocked or opened in any way other than using the entry
function or wireless remote control. (The door will lock again automatically.)
● A trunk is opened in any way other than using the entry function, wireless
remote control or mechanical key.
● The hood is opened.
● The tilt sensor detects a change of vehicle inclination. (if equipped)
Close the doors, trunk and hood, and
lock all the doors using the entry func-
tion or wireless remote control. The
system will be set automatically after
30 seconds. The indicator light changes from being
on to flashing when the system is set.
: If equipped
The alarm
Setting the alarm system

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1-3. Theft deterrent system
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GS450h_300h_OM_OM30F92E_(EE)
For safety and security
■Triggering of the alarm
The alarm may be triggered in the following situations:
(Stopping the alarm deactivates the alarm system.)
■Alarm-operated door lock
In the following cases, the door may automatically lock:
●When a person remain ing in the vehicle unlocks the d oor and the alarm is activated.
●While the alarm is activated, a person re maining in the vehicle unlocks the door.
●When recharging or replacing the 12-volt battery.
■Customization
The alarm can be set to deactivate when the mechanical key is used to unlock.
(Customizable features: P. 561)
●The doors are unlocked using the mechanical
key, or the trunk is opened using the mechani-
cal key.
●A person inside the vehicle opens a door, the
trunk or hood, or unlocks the vehicle using an
inside lock button.
●The 12-volt battery is recharged or replaced
when the vehicle is locked. ( P. 533)
NOTICE
■To ensure the system operates correctly
Do not modify or remove the system. If mo dified or removed, the proper operation of
the system cannot be guaranteed.