2019 Lexus ES300h ECU

531-3. Hybrid system
1
For safety and security
1-3.Hybrid system
The illustration is an example for explanation and may differ from the actual item.
Gasoline engine
Electric motor (traction motor)
■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.
When the shift lever is in N, the hybrid
battery (traction battery) is not being charged.
*: When the hybrid battery (traction bat-
tery) requires charging or the engine is
warming up, etc., the gasoline engine will
not automatically stop.
■During normal driving
The gasoline engine is predominantly
used. The electric motor (traction
motor) charges the hybrid battery
(traction battery) as necessary.
Hybrid system features
Your vehicle is a hybrid vehicle. It has characteristics different from conven-
tional vehicles. Be sure you are closely familiar with the characteristics of your
vehicle, and operate it with care.
The hybrid system combines the use of a gasoline engine and an electric motor
(traction motor) according to driving conditions, improving fuel efficiency and
reducing exhaust emissions.
System components
A
B

551-3. Hybrid system
1
For safety and security
soft clank will be emitted from the hybrid
battery (traction battery), behind the rear
seats, 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 transmis-
sion 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 regenera-
tive 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 vent under the rear seat.
■Maintenance, repair, recycling, and dis-
posal
Contact your Lexus dealer regarding main-
tenance, repair, recycling 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.412)
When driving with the gasoline engine
stopped, a sound, which changes in
accordance with the driving speed, will
be played in order to warn people
nearby of the vehicle’s approach. This
sound may be heard inside the vehicle.
The sound will stop when the vehicle
speed exceeds approximately 15 mph
(25 km/h).
■Vehicle proximity notification system
In the following cases, the vehicle proximity
notification system may be difficult for sur-
rounding people to hear.
●In very noisy areas
●In the wind or the rain
Also, as the vehicle proximity notification
system is installed on the front of the vehicle,
it may be more difficult to hear from the rear
of the vehicle compared to the front.
Vehicle proximity notification
system

571-3. Hybrid system
1
For safety and security
shielding, and therefore emit approxi-
mately the same amount of electromag-
netic waves as conventional gasoline
powered vehicles or home electronic
appliances.
●Your vehicle may cause sound interfer-
ence in some third party-produced radio
parts.
■Hybrid battery (traction battery)
The hybrid battery (traction battery) has a
limited service life. The lifespan of the
hybrid battery (traction battery) can
change in accordance with driving style and
driving conditions.
WARNING
■High voltage precautions
This vehicle has high voltage DC and AC
systems as well as a 12-volt system. 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 warning 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
subject to high voltage.
■Road accident cautions
Observe the following precautions to
reduce the risk of death or serious injury:
●Stop the vehicle in a safe place to pre-
vent subsequent accidents. While
depressing the brake pedal, apply the
parking brake and sh ift the shift lever
to P to stop the hybrid system. Then,
slowly release the brake pedal.
●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 elec-
tric wires.
●If a fluid leak occurs, do not touch the
fluid as it may be st rong alkaline elec-
trolyte from the hybrid battery (trac-
tion 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 solu-
tion. Seek immediate medical atten-
tion.
●If electrolyte is leaking from the hybrid
battery (traction battery), do not
approach the vehicle.
Even in the unlikely event that the
hybrid battery (traction battery) is
damaged, the internal construction of
the battery will prev ent a large amount
of electrolyte from leaking out. How-
ever, any electrolyte that does leak out
will give off a vapor. This vapor is an
irritant to skin and eyes and could
cause acute poisoning if inhaled.
●Do not bring burning or high-tem-
perature items close to the electrolyte.
The electrolyte may ignite and cause a
fire.
●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 danger-
ous.

591-3. Hybrid system
1
For safety and security
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 minimize the risk of electrocu-
tion and fuel leakage. If the emergency
shut off system activates, your vehicle
will not restart. To restart the hybrid system, contact your Lexus dealer.
A message is automatically displayed
when a malfunction occurs in the
hybrid system or an improper opera-
tion is attempted.
If a warning message is shown on the
multi-information display, read the
message and follow the instructions.
■If a warning light comes on, a warning
message is displayed, or the 12-volt bat-
tery is disconnected
The hybrid system may not start. In this
case, try to start the system again. If the
“READY” indicator does not come on, con-
tact your Lexus dealer.
NOTICE
■Hybrid battery (traction battery) air
intake vent
●Make sure not to block the air intake
vent with anything, such as a seat
cover, plastic cover, or luggage. If the
vents become blocked, the hybrid bat-
tery (traction battery) input and output
may be restricted, leading to a reduc-
tion in hybrid battery (traction battery)
output and a malfunction.
●When dust etc. has accumulated in the
air intake vent, periodically clean it
with a vacuum cleaner to prevent the
vent from clogging.
●A filter is installed to the air intake vent.
When the filter remains noticeably
dirty even after cleaning the air intake
vent, filter cleaning or replacement is
recommended. When cleaning or
replacing the filter, contact your Lexus
dealer.
Refer to P.304 for details on how to
clean the filter.
●Do not get water or foreign materials
in the air intake vent as this may cause
a short circuit and damage the hybrid
battery (traction battery).
●Do not carry large amounts of water
such as water cooler bottles in the
vehicle. If water spills onto the hybrid
battery (traction battery), the battery
may be damaged. Have the vehicle
inspected by your
Lexus dealer.
Emergency shut off system
Hybrid warning message

601-4. Theft deterrent system
1-4.Theft deterrent 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 can-
celed.
■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 touch-
ing a key registered to the security sys-
tem (key with a built-in transponder chip)
of another vehicle
■Certifications for the immobilizer system
For vehicles sold in the U.S.A. , Hawaii, Guam and Puerto Rico
Immobilizer system
The vehicle’s keys have built-in tran-
sponder chips that prevent the
hybrid system 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 pre-
vent vehicle theft but does not guar-
antee absolute security against all
vehicle thefts.
Operating the system

611-4. Theft deterrent system
1
For safety and security
For vehicles sold in Canada
NOTICE
■To ensure the system operates cor-
rectly
Do not modify or remove the system. If
modified or removed, the proper opera-
tion of the system cannot be guaranteed.

631-4. Theft deterrent system
1
For safety and security
●The 12-volt battery is recharged or
replaced when the vehicle is locked.
( P.386)
■Alarm-operated door lock
In the following cases, depending on the sit-
uation, the door may automatically lock to
prevent improper entry into the vehicle:
●When a person remaining in the vehicle
unlocks the door and the alarm is acti-
vated.
●While the alarm is activated, a person
remaining in the vehicle unlocks the door.
●When recharging or replacing the 12-volt
battery
NOTICE
■To ensure the system operates cor-
rectly
Do not modify or remove the system. If
modified or removed, the proper opera-
tion of the system cannot be guaranteed.

682-1. Instrument cluster
systems.
Turn signal indicator (P.145)
(U.S.A.) Headlight indicator (
P.150)
(Canada) Tail light indicator (
P.150)
Headlight high beam indicator
(  P.152)
Automatic High Beam indicator
(  P.153)
PCS warning light
*1, 2 (  P.171)
Cruise control indicator
(  P.194)
Dynamic radar cruise control
indicator ( P.187)
Cruise control “SET” indicator
(  P.187)
(white)
LTA indicator ( P.181)
(green)
LTA indicator ( P.181)
(orange)
(flashes)LTA indicator ( P.181)
BSM outside rear view mirror
indicators
*1, 3 (if equipped)
(  P.197, P.211)
BSM indicator (if equipped)
(  P.197)
Intuitive parking assist OFF indi-
cator
*1, 2 (if equipped)
(  P.205)
RCTA OFF indicator
*1, 2 (if
equipped) ( P.211)
RCD OFF indicator*2 (if
equipped) ( P.215)
PKSB OFF indicator
*1, 2 (if
equipped) ( P.219)
(flashes)
Slip indicator*1 ( P.236)
VSC OFF indicator
*1, 2
(  P.237)
Smart access system with push-
button start indicator ( P.135)
“READY” indicator ( P.135)
AGC indicator
*4 (  P.203)
EV drive mode indicator
(  P.139)
(U.S.A.) Parking brake indicator
(
 P.146)
(Canada) Parking brake indicator
(
 P.146)
Brake hold standby indicator
*1
(  P.148)
Brake hold operated indicator
*1
(  P.148)
EV indicator ( P.54)
Low outside temperature indi-
cator
*5 (  P.70)
Security indicator
*6 (  P.60,
P.62)
(U.S.A.) “AIR BAG ON/OFF” indica-
tor
*1, 6 (
 P.37)