2020 LEXUS NX300h battery

3546-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
1Lift the deck board and attach the
hook. ( P.307)
2 Remove the left side deck board.
3 Remove the cover after removing
the chip.
Press
Pull out
Make sure that the 12-volt battery ter-
minals are not corroded and that there
are no loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp
Insert the left side auxiliary box.
1 Push up center position
2 Insert
3 Press
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while
the hybrid system is operating. Also, be
sure all accessories are turned off.
Removing the 12-volt battery
maintenance cover
Exterior
A
B
Installing the 12-volt battery
maintenance cover
A
B

3686-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
■When the card key battery needs to be
replaced (if equipped)
The battery for the card key is available only
at Lexus dealers. Your Lexus dealer can
replace the battery for you.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operationa l range will be reduced.
Prepare the following before replacing
the battery:
Flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent
type recommended by the manufacturer.
●Dispose of used batteries according to
the local laws.
NOTICE
■When using the air conditioning sys-
tem
Make sure that a filter is always installed.
Using the air conditioning system without
a filter may cause damage to the system.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare

3696-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manual_USA_M78530_en
6
Maintenance and care
1 Take out the mechanical key.
2 Remove the cover.
To prevent damage to the key, cover the tip
of the flathead screwdriver with a tape.
3Remove the depleted battery.
Insert a new battery with the “+” terminal
facing up.
Replacing the batteryWARNING
■Removed battery and other parts
These parts are small and if swallowed by
a child, they can cau se choking. Keep
away from children. Failure to do so
could result in death or serious injury.
NOTICE
■For normal operation after replacing
the battery
Observe the following precautions to
prevent accidents:
●Always work with dry hands.
Moisture may cause the battery to
rust.
●Do not touch or move any other com-
ponent inside the remote control.
●Do not bend either of the battery ter-
minals.

377
LEXUS NX300h Owners Manual_USA_M78530_en
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers.................. 378
If your vehicle has to be stopped in an emergency .......................... 378
If the vehicle is trapped in rising water............................................ 379
7-2. Steps to take in an emergency If your vehicle needs to be towed......................................................... 381
If you think something is wrong ........................................................ 384
If a warning light turns on or a warning buzzer sounds ....... 386
If a warning message is displayed ........................................................ 396
If you have a flat tire.................. 400
If the hybrid system will not start ........................................................ 407
If you lose your keys ................. 409
If the fuel filler door cannot be opened........................................ 409
If the electronic key does not operate properly ..................... 410
If the 12-volt battery is discharged ......................................................... 412
If your vehicle overheats ......... 416
If the vehicle becomes stuck . 419

3787-1. Essential information
LEXUS NX300h Owners Manual_USA_M78530_en
7-1.Essential information
Press the switch.
All the turn signal lights will flash. To turn
them off, press the switch once again.
■Emergency flashers
If the emergency flashers are used for a
long time while the hybrid system is not
operating (while the “READY” indicator is
not illuminated), the 12-volt battery may dis-
charge.
1 Steadily step on the brake pedal
with both feet and firmly depress it.
Do not pump the brake pedal repeatedly
as this will increase the effort required to
slow the vehicle.
2Shift the shift lever to N.
If the shift lever is shifted to N
3 After slowing down, stop the vehi-
cle in a safe place by the road.
4 Stop the hybrid system.
If the shift lever cannot be shifted to
N
3 Keep depressing the brake pedal
with both feet to reduce vehicle
speed as much as possible.
4 To stop the hybrid system, press
and hold the power switch for 2
consecutive seconds or more, or
Emergency flashers
The emergency flashers are used to
warn other drivers when the vehicle
has to be stopped in the road due to
a breakdown, etc.
Operating instructions
If your vehicle has to be
stopped in an emergency
Only in an emergency, such as if it
becomes impossible to stop the
vehicle in the normal way, stop the
vehicle using the following proce-
dure:
Stopping the vehicle

3937-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
■Brake Override System/Drive-S tart Control warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (front door), side
impact sensors (rear), driver’s seat position
sensor, driver’s seat be lt buckle switch, front
passenger occupant cl assification system
(ECU and sensors), “AIR BAG ON” indi-
cator light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch,
driver’s seat belt pretensioner, front passen-
ger’s seat belt pretensioner and force lim-
iter, airbags, interconnecting wiring and
power sources. ( P.32)
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■Electric power steering system warning
light (warning buzzer)
When the 12-volt battery charge becomes
insufficient of the voltage temporarily drops,
the electric power steering system warning
light may come on and the warning buzzer
may sound.
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
Warning lightDetails/Actions
Brake Override System
Indicates that the accelerato r and brake pedals are being
depressed simultaneously, and the Brake Override System
is operating.
 Release the accelerator pedal and depress the brake
pedal.
Indicates a malfunction in the Brake Override System (with
warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.
Drive-Start Control
Indicates that the shift position was changed and Drive-
Start Control was operated wh ile depressing the accelera-
tor pedal. (with warning buzzer)
 Momentarily release th e accelerator pedal.
Indicates a malfunction in th e Drive-Start Control system
(with warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.

3977-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
*: A buzzer sounds the first time a message is shown on the multi-information display.
■System warning lights
The master warning light does not come on
or flash in the following cases. Instead, a
separate system warning light will come on
along with a message shown on the multi-
information display.
●Malfunction of the ABS
The ABS warning light comes on.
(  P.388)
●Malfunction of the charging system
The charging system warning light comes
on. ( P.386)
■If “Hybrid System Overheated Output
power reduced” is shown
This message may be displayed when driv-
ing under severe operating conditions. (For
example, when driving up a long steep hill.)
Handling method: P.416
■If “Traction Battery Needs to be Pro-
tected Refrain From the Use of N Posi-
tion” is shown
This message may be displayed when the shift lever is in N.
As the hybrid battery (traction battery) can
not be charged when the shift lever is in N,
shift the shift lever to P when the vehicle is
stopped.
■If “Traction Battery Needs to be Pro-
tected. Shift into P to
Restart.” is shown
This message is displayed when the hybrid
battery (traction battery) charge has
become extremely low because the shift
lever has been left in N for a certain amount
of time.
When operating the vehicle, shift to P and
restart the hybrid system.
■If “Shift to P Before Exiting Vehicle” is
shown
Message is displayed when the driver’s
door is opened without turning the power
switch to OFF with the shift lever in any
position other than P.
Shift the shift lever to P.
■If “Shift Is in N Release Accelerator
Before Shifting” is shown
Message is displayed when the accelerator
System
warning light
Warning buzzer*Warning
Comes onSounds
Indicates an important situation, such as
when a system related to driving is malfunc-
tioning or that danger may result if the cor-
rection procedure is not performed

Comes on or
flashes
Sounds
Indicates an important situation, such as
when the systems shown on the multi-infor-
mation display may be malfunctioning
FlashesSoundsIndicates a situation, such as when damage
to the vehicle or danger may result
Comes onDoes not sound
Indicates a condition, such as malfunction of
electrical components, their condition, or
indicates the need for maintenance
FlashesDoes not sound
Indicates a situation, such as when an opera-
tion has been performed incorrectly, or indi-
cates how to perform an operation correctly

3987-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_enpedal has been depressed and the shift
lever is in N. Release the accelerator pedal
and shift the shift lever to D, S or R.
■If “Depress Brake When Vehicle Is
Stopped Hybrid Syst
em May Overheat”
is shown
Message is displayed when the accelerator
pedal is depressed to maintain the vehicle
position when stopped on a upward slope,
etc.
If this continues, th e hybrid system may
overheat.
Release the accelerator pedal and depress
the brake pedal.
■If “Front Camera Unavailable” or “Front
Camera Unavailable See Owner’s
Manual” is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.208, 389)
●PCS (Pre-Collision System)
●LTA (Lane Tracing Assist)
●LDA (Lane Departure Alert with steering
control)
●Automatic High Beam
●RSA (Road Sign Assist)
●Dynamic radar cruise control with full-
speed range
■If “RSA malfunction Visit Your Dealer” is
shown
The system may be malfunctioning. Have
the vehicle inspected by your Lexus dealer.
■If “Radar Cruise Control Unavailable
See Owner’s Manual” is shown
The dynamic radar cruise control with full-
speed range system is suspended tempo-
rarily or until the problem shown in the mes-
sage is resolved. (causes and coping
methods: P.208)
■If “Radar Cruise Control Unavailable” is
shown
The dynamic radar cruise control with full-
speed range system cannot be used tempo-
rarily. Use the system when it becomes
available again.
■If “Oil Maintenance Required Soon” is
shown
Indicates that the engine oil is scheduled to
be changed. (The indicator will not work
properly unless the oil maintenance data
has been reset.)
Check the engine oil, and change if neces-
sary. After changing th e engine oil, the oil
change system should be reset. ( P.348)
■If “Oil Maintenance Required” is shown
Indicates that the engine oil should be
changed. (After the engine oil is changed
and the oil maintenance data has been
reset.)
Check and change the en gine oil, and oil fil-
ter by your Lexus dealer. After changing the
engine oil, the oil change system should be
reset. ( P.348)
■If “See Owner’s Manual” is shown
●If the following messages are shown, fol-
lowing the instruct ions, accordingly.
• “Engine Coolant Temp High” ( P.416)
●If the following messages are shown,
there may be a malfunction.
Immediately have the vehicle inspected
by your Lexus dealer.
• “Hybrid System Malfunction”
•“Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Braking Power Low”
• “Smart Access System Malfunction”
●If “Aux Battery Low” is shown
• When the display goes off after several
seconds
*
Maintain the hybrid system operation for
more than 15 minutes and charge the 12-
volt battery.
• When the display does not go off Start up the hybrid system using the pro-
cedures for “If the 12-volt battery is dis-
charged” ( P.412).
*: Displays for about 6 seconds
●If “Maintenance required for Traction bat-
tery cooling parts” is shown, the filters
may be clogged, the air intake vents may
be blocked, or there may be a gap in the
duct. Therefore, perform the following
correction procedure.
• If the air intake vents of the hybrid battery