2019 LEXUS NX300H change key battery

711-3. Theft deterrent system
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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 (if
equipped) are closed before the
alarm is set.
 No valuables or other personal
items are left in the vehicle.
■Setting
Close the doors and hood, and lock all
the doors. The system will be set auto-
matically after 30 seconds.
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 alarms:
 Unlock the doors.
 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.)
●A person inside the vehicle opens a door
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.394)
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.)
 The hood is opened.
Setting/canceling/stopping the
alarm system

1063-2. Opening, closing and locking the doors
LEXUS NX300h Owners Manu-
al_USA_M78287_en
■Door lock 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.121
■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.
■Customization
Settings (e.g. unloc king function using a
key) can be changed. (Customizable fea-
tures:  P.421)
■Using the door lock switch
1 Locks all the doors
2 Unlocks all the doors
WARNING
■To prevent an accident
Observe the following precautions while
driving the vehicle.
Failure to do so may result in a door
opening and an occupant falling out,
resulting in death or serious injury.
●Ensure that all doors are properly
closed and locked.
●Do not pull the inside handle of the
doors while driving.
Be especially care ful for the front
doors, as the door s may be opened
even if the inside lock buttons are in
locked position.
●Set the rear door ch ild-protector locks
when children are seated in the rear
seats.
■When opening or closing a door
Check the surroundings of the vehicle
such as whether the vehicle is on an
incline, whether there is enough space
for a door to open and whether a strong
wind is blowing. When opening or clos-
ing the door, hold the door handle tightly
to prepare for any unpredictable move-
ment.
■When using the wireless remote con-
trol and operating the power windows
or moon roof (if equipped)
Operate the power window or moon
roof after checking to make sure that
there is no possibility of any passenger
having any of their body parts caught in
the window or moon roof. Also do not let
a child operate window by the mechani-
cal key. It is possible for children and
other passengers to get caught in the
power window or moon roof.
Unlocking and locking the doors
from the inside

1223-2. Opening, closing and locking the doors
LEXUS NX300h Owners Manu-
al_USA_M78287_enemit radio waves
• Portable radio, cellular phone, cordless phone or other wireless communication
devices
• Another vehicle’s electronic key or a wireless key that emits radio waves
• Personal computers or personal digital assistants (PDAs)
• Digital audio players
• Portable game systems
●If window tint with a metallic content or
metallic objects are attached to the rear
window
●When the electronic key is placed near a
battery charger or electronic devices
■Note for the entry function
●Even when the electronic key is within the
effective range (detection areas), the sys-
tem may not operate properly in the fol-
lowing cases:
• The electronic key is too close to the win- dow or outside door handle, near the
ground, or in a high place when the doors
are locked or unlocked.
• The electronic key is near the ground or
in a high place, or too close to the rear
bumper center when the back door is
opened.
• The electronic key is on the instrument panel, luggage room, floor, or in the door
pockets or glove box when the hybrid
system is started or power switch modes
are changed.
●Do not leave the electronic key on top of
the instrument panel or near the door
pockets when exiting the vehicle.
Depending on the radio wave reception
conditions, it may be detected by the
antenna outside the cabin and the door
will become lockable from the outside,
possibly trapping the electronic key
inside the vehicle.
●As long as the electron ic key is within the
effective range, the doors may be locked
or unlocked by anyone.
●Even if the electronic key is not inside the
vehicle, it may be possible to start the
hybrid system if the electronic key is near
the window.
●The doors may unlock if a large amount
of water splashes on the door handle, such as in the rain or in a car wash when
the electronic key is
within the effective
range. (The door will automatically be
locked after approximately 60 seconds if
the doors are not opened and closed.)
●If the wireless remote control is used to
lock the doors when the electronic key is
near the vehicle, there is a possibility that
the door may not be unlocked by the
entry function. (Use the wireless remote
control to unlock the doors.)
●Touching the door lock sensor while
wearing gloves may delay or prevent lock
operation. Remove the gloves and touch
the lock sensor again.
●When the lock operation is performed
using the lock sensor, recognition signals
will be shown up to two consecutive
times. After this, no recognition signals
will be given.
●If the door handle becomes wet while the
electronic key is within the effective
range, the door may lock and unlock
repeatedly. In that case, follow the follow-
ing correction procedures to wash the
vehicle:
• Place the electronic key in a location 6 ft. (2 m) or more away from the vehicle.
(Take care to ensure that the key is not
stolen.)
• Set the electronic key to battery-saving mode to disable the smart access system
with push-button start. ( P.121)
●If the electronic key is inside the vehicle
and a door handle becomes wet during a
car wash, a message may be shown on
the multi-information display and a
buzzer will sound outside the vehicle. To
turn off the alarm, lock all the doors.
●The lock sensor may not work properly if
it comes into contact with ice, snow, mud,
etc. Clean the lock sensor and attempt to
operate it again.
●A sudden approach to the effective
range or door handle may prevent the
doors from being unlocked. In this case,
return the door handle to the original
position and check that the doors unlock
before pulling the door handle again.
●If there is another electronic key in the
detection area, it may take slightly longer

1684-2. Driving procedures
LEXUS NX300h Owners Manu-
al_USA_M78287_en
4-2.Driving procedures
1Check that the parking brake is set.
2 Check that the shift lever is in P.
3 Firmly depress the brake pedal.
and a message will be displayed on the
multi-information display.
If it is not displayed, the hybrid system can-
not be started.
4 Press the power switch shortly and
firmly.
When operating the power switch, one
short, firm press is enough.
It is not necessary to press and hold the
switch.
If the “READY” indicator turns on, the
hybrid system will operate normally.
Continue depressing the brake pedal until
the “READY” indicator is illuminated.
The hybrid system can be started from any
power switch mode.
5Check that the “READY” indicator
is illuminated.
The vehicle will not move when the
“READY” indicator is off.
■If the hybrid system does not start
●The immobilizer system may not have
been deactivated. ( P.69)
Contact your Lexus dealer.
●Check that the shift leve r is securely set in
P. The hybrid system may not start if the
shift lever is displaced out of P. “To Start
Vehicle, Put Shift Lever into P” will be dis-
played on the multi-information display.
●The smart access system with push-but-
ton start may not be operating prop-
erly.( P.390)
■When the ambient temperature is low,
such as during winter driving conditions
When starting the hybrid system, the flash-
ing time of the “READY” indicator may be
long. Leave the vehicle as it is until the
“READY” indicator is steady on, as steady
means the vehicle is able to move.
■Sounds and vibrations specific to a
hybrid vehicle
 P.63
■Electronic key battery depletion
 P.100
■Conditions affecting operation
 P.121
■Note for the entry function
 P.122
■Steering lock function
●After turning the power switch off and
opening and closing the doors, the steer-
ing wheel will be lock ed due to the steer-
ing lock function. Operating the power
switch again automatically cancels the
steering lock.
●When the steering lock cannot be
released, “Steering Wheel Lock Press
Power Switch while Turning Wheel” will
be displayed on the multi-information dis-
play.
Power (ignition) switch
Performing the following opera-
tions when carryin g the electronic
key on your person starts the hybrid
system or changes power switch
modes.
Starting the hybrid system

1694-2. Driving procedures
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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Driving
Check that the shift leve r is in P. Press the
power switch while turning the steering
wheel left and right.
●To prevent the steering lock motor from
overheating, operation of the motor may
be suspended if the hybrid system is
turned on and off repeatedly in a short
period of time. In this case, refrain from
operating the hybrid system. After about
10 seconds, the stee ring lock motor will
resume functioning.
■If “Smart Access System Malfunction
See Owner’s Manual” is displayed on
the multi-inform ation display
The system may be malfunctioning. Have
the vehicle inspected by your Lexus dealer
immediately.
■If the “READY” indicator does not come
on
In the event that the “READY” indicator
does not come on even after performing
the proper procedures for starting the vehi-
cle, contact your Lexus dealer immediately.
■If the hybrid system is malfunctioning
 P.67
■Electronic key battery
 P.349
■Operation of the power switch
●If the switch is not pressed shortly and
firmly, the power switch mode may not
change or the hybrid system may not
start.
●If attempting to restart the hybrid system
immediately after turning the power
switch off, the hybrid system may not start
in some cases. After turning the power
switch off, please wait a few seconds
before restarting the hybrid system.
■Customizable functions
 P.423
1 Stop the vehicle completely.
2 Set the parking brake ( P.178),
and shift the shift lever to P
( P.173).
3 Press the power switch.
WARNING
■When starting the hybrid system
Always start the hybrid system while sit-
ting in the driver’s seat. Do not depress
the accelerator pedal while starting the
hybrid system under any circumstances.
Doing so may cause an accident result-
ing in death or serious injury.
■Caution while driving
If hybrid system failure occurs while the
vehicle is moving, do not lock or open the
doors until the vehicle reaches a safe and
complete stop. The steering lock func-
tion will activate and this may lead to an
accident, resulting in death or serious
injury.
NOTICE
■When starting the hybrid system
If the hybrid system becomes difficult to
start, have your vehicle checked by your
Lexus dealer immediately.
NOTICE
■Symptoms indicating a malfunction
with the power switch
If the power switch seems to be operat-
ing somewhat differently than usual, such
as the switch sticking slightly, there may
be a malfunction. Contact your Lexus
dealer immediately.
Stopping the hybrid system

3917-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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When trouble arises
ACCESSORY mode.
3 Firmly depress the brake pedal and
check that message shown on the
multi-information display.
4 Press the power switch.
In the event that the hybrid system still can-
not be operated, contact your Lexus
dealer.
■Stopping the hybrid system
Set the parking brake, shift the shift lever to
P and press the power switch as you nor-
mally do when stopping the hybrid system.
■Electronic key battery
As the above procedure is a temporary
measure, it is recomme nded that the elec-
tronic key battery be replaced immediately
when the battery is depleted.
■Alarm
Using the mechanical key to lock the doors
will not set the alarm system. If a door is
unlocked using the mechanical key when
the alarm system is set, the alarm may be
triggered.
■Changing power switch modes
Release the brake pe dal and press the
power switch in step 3 above.
The hybrid system does not start and modes
will be changed each time the switch is
pressed. ( P.170)

3947-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
■Starting the hybrid system when the 12-
volt battery is discharged
The hybrid system cannot be started by
push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio sys-
tem while the hybrid system is off.
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradua lly even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.)
■When the 12-volt battery is removed or
discharged
●In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
12-volt battery is discharged. Use the
wireless remote control or the mechani-
cal key to lock or unlock the doors.
●The hybrid system may not start on the
first attempt after the 12-volt battery has
recharged but will start normally after the
second attempt. This is not a malfunction.
●The power switch mode is memorized by
the vehicle. When the 12-volt battery is
reconnected, the system will return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
the 12-volt battery, turn the power switch
off.
If you are unsure what mode the power
switch was in before the 12-volt battery
discharged, be especially careful when
reconnecting the 12-volt battery.
●Some systems may require initialization.
■When replacing the 12-volt battery
●Use a 12-volt battery that the case size is
same as the previous one (LN2), 20 hour
rate capacity (20HR) is equivalent
(60Ah) or greater, and performance rat-
ing (CCA) is equivalent (460A) or
greater.
• If the sizes differ, the 12-volt battery can-
not be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and hybrid system may
not be able to start.
●After exchanging, firmly attach the fol-
lowing items to the exhaust hole of the 12-
volt battery.
• Use the exhaust hose that was attached to the 12-volt battery before
exchanging and confirm that it is firmly
connected to the hole section of the vehi-
cle.
• Use the exhaust hole plug included
with the 12-volt battery exchanged or the
one installed on the battery prior to the
exchange. (Depending on the 12-volt
battery to be exchanged, the exhaust
hole may be plugged.)
For details, consult your Lexus dealer.
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