2021 LEXUS ES300h ECU

631-4. 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.420)
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 22 mph
(35 km/h).
■Acoustic vehicle alerting system
In the following cases, the acoustic vehicle
alerting system may be difficult for sur-
rounding people to hear.
●In very noisy areas
●In the wind or the rain
Acoustic Vehicle Alerting Sys-
tem

651-4. 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 dr iving style and driving
conditions.
■Starting the hybrid system in an
extremely cold environment (for vehi-
cles sold in except Canada)
When the hybrid battery (traction battery)
is extremely cold (below approximately -
22°F [-30°C]) under the influence of the
outside temperature, it may not be possible
to start the hybrid system. In this case, try to
start the hybrid system again after the tem-
perature of the hybrid battery increases
due to the outside temperature increase
etc.
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 under the rear
seat (right side). 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 de ath 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 ar e exposed inside or
outside your vehicle, an electric shock
may occur. Neve r touch exposed
electric wires.
●For vehicles sold in Canada: If a fluid
leak occurs, do not touch the fluid as it
may be strong alkaline electrolyte
from the hybrid battery (traction bat-
tery). If it comes into contact with your
skin or eyes, wash it off immediately
with a large amount of water or, if pos-
sible, boric acid solution. Seek imme-
diate medical attention.

671-4. Hybrid system
1
For safety and security
There is an air intake vent under the
rear seat (right side) for the purpose of
cooling the hybrid battery (traction
battery). If the vent becomes blocked,
the hybrid battery (traction battery)
may overheat, leading to a reduction in
the hybrid battery (traction 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 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
NOTICE
■Hybrid battery (traction battery)
Do not carry large amounts of water
such as water cooler bottles in the vehi-
cle. If water spills onto the hybrid battery
(traction battery), the battery may be
damaged. Have the vehicle inspected by
your Lexus dealer.
Hybrid battery (traction battery)
air intake vent
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 re mains 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.344 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

691-5. Theft deterrent system
1
For safety and security
1-5.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
transponder 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

711-5. Theft deterrent system
1
For safety and security
■Items to check before locking the
vehicle
To prevent unexpected triggering of
the alarm and vehicle theft, make sure
of the following:
 Nobody is in the vehicle.
 The windows and moon roof are
closed before the alarm is set.
 No valuables or other personal
items are left in the vehicle.
■Setting
Close the doors, trunk and hood, and
lock all the doors using the entry func- tion or wireless re
mote control. The
system will be set automatically after
30 seconds.
Except for Canada, the alarm can also
be set using the mechanical key.
The indicator light changes from being on
to flashing when the system is set.
■Canceling or stopping
Do one of the following to deactivate
or stop the alarm:
 Except for Canada: Unlock the
doors using the entry function, wire-
less remote control or mechanical
key.
 For Canada: Unlock the doors using
the entry function or wireless
remote control.
 Turn the power switch to ACCES-
SORY or ON mode, or start the
hybrid system. (The alarm will be
deactivated or stopped after a few
seconds.)
■System maintenance
The vehicle has a maintenance-free type
alarm system.
■Triggering of the alarm
The alarm may be triggered in the following
situations:
(Stopping the alarm deactivates the alarm
system.)
Alarm
The alarm uses light and sound to
give an alert when an intrusion is
detected.
The alarm is triggered in the follow-
ing situations when the alarm is set:
 A locked door is unlocked or
opened in any way other than
using the entry function, wireless
remote control or mechanical
key
*. (The doors will lock again
automatically.)
 A locked trunk is unlocked or
opened in any way other than
using the entry function or wire-
less remote control.
 The hood is opened.
*:Except for Canada
Setting/canceling/stopping the
alarm system

1013-2. Opening, closing and locking the doors and trunk
3
Before driving
3-2.Opening, closing and locking the doors and trunk
■Smart access system with push-
button start
Carry the electronic key to enable this
function.
1 Grip the driver’s door handle to
unlock the door. Holding the
driver’s door ha ndle for approxi-
mately 2 seconds unlocks all the
doors. Grip the passenger’s door
handle to unlock all the doors.
*
Make sure to touch the sensor on the back
of the handle.
The doors cannot be unlocked for 3 sec-
onds after the doors are locked.
*: The door unlock settings can be changed.
2 Touch the lock sensor (the indenta-
tion on the upper part of the door
handle) to lock all the doors.
Check that the door is securely locked.
■Wireless remote control
1 Locks all the doors
Check that the door is securely locked.
2Unlocks all the doors
Pressing the button unlocks the driver’s
door. Pressing the button again within 5
seconds unlocks the other doors.
Press and hold to open the windows and
moon roof.
*
*
: This setting must be customized at your Lexus dealer.
■Switching the door unlock function
It is possible to set which doors the entry
function unlocks using the wireless remote
control.
1 Turn the power switch off.
2 When the indicator light on the key sur-
face is not on, press and hold ,
or for approximately 5
seconds while pre ssing and holding
.
The setting changes each time an operation
is performed, as shown below. (When
changing the setting continuously, release
the buttons, wait for at least 5 seconds, and
repeat step 2 .)
Doors
Unlocking and locking the doors
from the outside

1023-2. Opening, closing and locking the doors and trunk
To prevent unintended triggering of the
alarm, unlock the doors using the wireless
remote control and open and close a door
once after the settings have been changed.
(If a door is not opened within 60 seconds
after is pressed, the doors will be
locked again and the alarm will automati-
cally be set.)
In a case that the alarm is triggered, imme-
diately stop the alarm. (P.71)
■Impact detection door lock release sys-
tem
In the event that the vehicle is subject to a
strong impact, all the doors are unlocked.
Depending on the force of the impact or the
type of accident, however, the system may
not operate.
■Operation signals
A buzzer sounds and the emergency flash-
ers flash to indicate that the doors have
been locked/unlocked. (Locked: once;
Unlocked: twice)
Windows and moon roof: A buzzer sounds
to indicate that the windows and moon roof
are opening.
■Security feature
If a door is not opened within approximately
60 seconds after the vehicle is unlocked,
the security feature automatically locks the
vehicle again. (However, depending on the
location of the electronic key, the key may
be detected as being in the vehicle. In this
case, vehicle may be unlocked.)
■When the doors cannot be locked by
the lock sensor on the upper part of the
door handle
When the doors cannot be locked even if
the lock sensor on the surface of the door
handle is touched by a finger, touch the lock
sensor with the palm.
If you are wearing gloves, remove them.
■Open door warning buzzer
If an attempt to lock the doors is made when
a door is not fully closed, a buzzer sounds
continuously for 5 seconds. Fully close the
door to stop the buzzer, and lock the vehi-
cle once more.
■Setting the alarm
Locking the doors will set the alarm system.
(  P.71)
■Conditions affecting the operation of
the smart access system with push-but-
ton start or wireless remote control
 P.114
■If the smart access system with push-
button start or the wireless remote con-
trol does not operate properly
Use the mechanical key to lock and unlock
the doors. ( P.389)
Replace the key battery with a new one if it
is depleted. ( P.347)
■If the 12-volt batte ry is discharged
The doors cannot be locked and unlocked
using the smart access system with push-
Multi-information display/BeepUnlocking function
Exterior: Beeps 3 times
Interior: Pings once
Holding the driver’s
door handle unlocks
only the driver’s door.
Holding a passenger’s
door handle unlocks all
the doors.
Exterior: Beeps twice
Interior: Pings onceHolding a door handle
unlocks all the doors.

1053-2. Opening, closing and locking the doors and trunk
3
Before driving
Trunk
The trunk can be opened using the
trunk opener switch, entry function
or wireless remote control.
If the vehicle is equipped with a
power trunk lid, the trunk can be
closed using the trunk closer.
WARNING
Observe the following precautions.
Failure to do so may result in death or
serious injury.
■Before driving
●Make sure that the trunk lid is fully
closed. If the trunk lid is not fully
closed, it may open unexpectedly
while driving and hit near-by objects or
luggage in the trun k may be thrown
out, causing an accident.
●Do not allow children to play in the
trunk.
If a child is accidentally locked in the
trunk, they could suffer from heat
exhaustion, suffocation or other inju-
ries.
●Do not allow a child to open or close
the trunk lid.
Doing so may cause the trunk lid to
open unexpectedly, or cause the
child’s hands, head, or neck to be
caught by the closing trunk lid.
■Important points while driving
Never let anyone sit in the trunk. In the
event of sudden braking or a collision,
they are susceptible to death or serious
injury.
■Using the trunk
Observe the following precautions.
Failure to do so may cause parts of the
body to be caught, resulting in serious
injury.
●Remove any heavy loads, such as
snow and ice, from the trunk lid before
opening it. Failure to do so may cause
the trunk lid to suddenly shut again
after it is opened.
●When opening or closing the trunk lid,
thoroughly check to make sure the
surrounding area is safe.
●If anyone is in the vicinity, make sure
they are safe and let them know that
the trunk is about to open or close.
●Use caution when opening or closing
the trunk lid in windy weather as it may
move abruptly in strong wind.
●Vehicles without power trunk lid: The
trunk lid may suddenly shut if it is not
opened fully. It is more difficult to open
or close the trunk lid on an incline than
on a level surface, so beware of the
trunk lid unexpectedly opening or
closing by itself. Ma ke sure that the
trunk lid is fully open and secure
before using the trunk.
●When closing the trunk lid, take extra
care to prevent your fingers etc. from
being caught.