Page 82 of 1014
811-2. Hybrid system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
When stopped/during start off
The gasoline engine stops when the vehicle is stopped. During
start off, the electric motor (traction motor) drives the vehicle. At
slow speeds or when traveling down a gentle slope, the engine is
stopped and the electric motor (traction motor) is used.
During normal driving
The gasoline engine is predominantly used. The electric motor
(traction motor) charges the hybrid battery (traction battery) as
necessary.
When accelerating sharply
When the accelerator pedal is depressed heavily, the power of the
hybrid battery (traction battery) is added to that of the gasoline
engine via the electric motor (traction motor).
When braking (regenerative braking)
The electric motor (traction motor) charges the hybrid battery
(traction battery).
Page 84 of 1014

831-2. Hybrid system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
After the 12-volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is running on the hybrid
battery (traction battery). If this continues for a few days, contact any autho-
rized Lexus dealer or repairer, or another duly qualified and equipped profes-
sional.
Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibration even though the vehicle is able
to move. For safety, apply the parking brake and make sure to shift the shift
position to P when parked.
The following sounds or vibrations may occur 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.
Sounds from the hybrid system may be heard when the trunk lid is open.
Sounds may be heard from the hybrid transmission when the hybrid system
starts or stops.
Engine sounds may be heard when accelerating sharply.
Sounds may be heard due to regenerative braking when the brake pedal is
depressed.
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 dealer or repairer, or another duly qualified
and equipped professional regarding maintenance, repair, recycling and dis-
posal. Do not dispose of the vehicle yourself.
Customization
Settings (e.g. on/off operation of the EV indicator) can be changed.
(Customizable features: P. 942)
Page 86 of 1014

851-2. Hybrid system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
There are air intake vents on the
both sides of the rear seatback
for the purpose of cooling the
hybrid battery (traction battery).
If the vents become blocked, the
hybrid battery may overheat,
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 off the high voltage current and
stops the fuel pump to minimize 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 dealer or repairer, or another duly qualified and equipped
professional.
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. 838)
Hybrid battery (traction battery) air vents
Emergency shut off system
Hybrid warning message
Page 88 of 1014
871-2. Hybrid system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
CAUTION
High voltage precautions
The vehicle has high voltage DC and AC systems as well as a 12-volt sys-
tem. DC and AC high voltage is very dangerous and can cause severe burns
and electric shock that may result in death or serious injury.
Never touch, disassemble, remove or replace the high voltage parts,
cables or their connectors.
The hybrid system will become hot after starting as the system uses high
voltage. Be careful of both the high voltage and the high temperature, and
always obey the caution labels attached to the vehicle.
Never try to open the service plug
access hole located behind the rear
seats. The service plug is used only
when the vehicle is serviced and is sub-
ject to high voltage.
Page 90 of 1014

891-2. Hybrid system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
CAUTION
Hybrid battery (traction battery)
Your vehicle contains a sealed nickel-metal hydride battery. Never resell,
hand over or modify the hybrid battery. To prevent accidents, hybrid bat-
teries that have been removed from a disposed vehicle are collected
through any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional. Do not dispose of the battery yourself.
Unless the battery is properly collected, the following may occur, result-
ing in death or serious injury:
• The hybrid battery may be illegally disposed of or dumped, and some-
one may touch a high voltage part, resulting in an electric shock.
• The hybrid battery is intended to be used exclusively with your hybrid
vehicle. If the hybrid battery is used outside of your vehicle or modified
in any way, accidents such as electric shock, heat generation, smoke
generation, an explosion and electrolyte leakage may occur.
When reselling or handing over your vehicle, the possibility of an acci-
dent is extremely high because the person receiving the vehicle may not
be aware of these dangers.
If your vehicle is disposed of without the hybrid battery having been
removed, there is a danger of serious electric shock if high voltage parts,
cables and their connectors are touched. In the event that your vehicle
must be disposed of, the hybrid battery must be disposed of by any autho-
rized Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional. If the hybrid battery is not disposed of properly, it may cause
electric shock that can result in death or serious injury.
Page 92 of 1014

91
1 1-3. Theft deterrent system
GS450h_300h_OM_OM30D53E_(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 indicate 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 transponder chips that prevent the
hybrid system from starting if a key has not been previously regis-
tered 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 prevent vehicle theft but does not
guarantee absolute security against all vehicle thefts.
Page 94 of 1014
931-3. Theft deterrent system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
Page 96 of 1014
951-3. Theft deterrent system
1
GS450h_300h_OM_OM30D53E_(EE)
For safety and security
NOTICE
To ensure the system operates correctly
Do not modify or remove the system. If modified or removed, the proper
operation of the system cannot be guaranteed.