2020 LEXUS NX300 battery

3566-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_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 operational 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

3576-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
1Take 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 cause 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.

365
LEXUS NX300 Owners Manual_USA_M78389_en
7
7
When trouble arises
When trouble arises
7-1. Essential information
Emergency flashers.................. 366
If your vehicle has to be stopped in an emergency .......................... 366
If the vehicle is trapped in rising water............................................ 367
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 369
If you think something is wrong ........................................................ 373
Fuel pump shut off system ..... 374
If a warning light turns on or a warning buzzer sounds ....... 375
If a warning message is displayed ........................................................ 384
If you have a flat tire.................. 387
If the engine wi ll not start .......395
If you lose your keys ................. 396
If the fuel filler door cannot be opened........................................ 397
If the electronic key does not operate properly .................... 397
If the vehicle battery is discharged ........................................................ 400
If your vehicle overheats ........ 403
If the vehicle becomes stuck 406

3667-1. Essential information
LEXUS NX300 Owners Manual_USA_M78389_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 engine is not operating,
the battery may discharge.
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 engine.
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 engine, press and hold
the engine switch for 2 consecutive
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

3817-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_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 battery charge becomes insuffi-
cient 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 accelerator and brake pedals are being
depressed simultaneously, and the Brake Override Sys-
tem is operating.
 Release the accelerator pe dal 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 acceler-
ator pedal. (with warning buzzer)
 Momentarily release th e accelerator pedal.
Indicates a malfunction in the Drive-Start Control system
(with warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.

3867-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
speed range
■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.197)
■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 the engine oil, the oil
change system shou ld be reset. (P.337)
■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 deal er. After changing the
engine oil, the oil change system should be
reset. ( P.337)
■If “See Owner’s Manual” is shown
●If the following messages are shown, fol-
lowing the instructions, accordingly.
• “Engine Coolant Temp High” ( P.403)
●If the following messages are shown,
there may be a malfunction.
Immediately have the vehicle inspected
by your Lexus dealer.
• “Braking Power Low”
• “Smart Access System Malfunction”
●If the following messages are shown,
there may be a malfunction.
Immediately stop the vehicle in a safe
place and contact your Lexus dealer.
Continuing to drive the vehicle may be
dangerous.
• “Oil Pressure Low” • “Charging System Malfunction”
• “Transmission Fluid Temp High”
■Warning buzzer
 P.382
NOTICE
■“High Power Consumption Partial
Limit On AC/Heater Operation” is
frequently shown
There is a possible malfunction relating
to the charging system or the battery
may be deteriorating. Have the vehicle
inspected by your Lexus dealer.

3957-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
7
When trouble arises
One of the following may be the cause
of the problem:
There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle.
 The engine may be flooded.
Try to restart the engine again fol-
lowing correct starting proce-
dures.( P.165)
 There may be a malfunction in the
engine immobilizer system.
( P.68)
One of the following may be the cause
of the problem:
 The battery terminal connections
may be loose or corroded.
 The battery may be discharged.
( P.400) The engine starting system may be
malfunctioning due to an electrical
problem such as electronic key battery
depletion or a blown fuse. However, an
interim measure is available to start the
engine. (
P.395)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected.
 The battery may be discharged.
( P.400)
 There may be a malfunction in the
steering lock system.
Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the engine does not start, the
following steps can be used as an
interim measure to start the engine if
the engine switch is functioning nor-
mally.
Do not use this starting procedure
except in cases of emergency.
1 Set the parking brake.
If the engine will not start
If the engine will not start even
though correct starting procedures
are being followed ( P.165), con-
sider each of the following points:
The engine will not start even
though the starter motor oper-
ates normally.
The starter motor turns over
slowly, the interior lights and
headlights are dim, or the horn
does not sound or sounds at a low
volume.
The starter motor does not turn
over
The starter motor does not turn
over, the interior lights and head-
lights do not turn on, or the horn
does not sound.
Starting the engine in an emer-
gency

3977-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
7
When trouble arises
1Remove the cover inside the lug-
gage compartment by inserting a
screwdriver.
When removing the cover, to pre-
vent damage, cover the tip of the
screwdriver with a rag.
2
After removing the cover, pull the
lever to unlock the fuel filler door
and it will be ready to open as usual.
■Things to check before taking measures
●Make sure that the smart access system
with push-button start has not been deac-
tivated in the customizat ion setting. If it is
off, turn the function on.
●Check if battery-saving mode is set. If it is
set, cancel the function. ( P.117)
Use the mechanical key ( P.98) to
perform the following operations.
If the fuel filler door cannot
b
e opened
If the fuel filler door opener switch
cannot be operated, the following
procedure can be used to open the
fuel filler door.
Opening the fuel filler door
If the electronic key does not
o
perate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.118) or the electronic
key cannot be used because the
battery is depleted, the smart
access system with push-button
start and wireless remote control
cannot be used. In such cases, the
doors can be opened and the
engine can be started by following
the procedure below.
NOTICE
■In case of a smart access system with
push-button start malfunction or
other key related problems
Take your vehicle with all the electronic
keys provided with your vehicle, includ-
ing the card key, to your Lexus dealer.
Locking and unlocking the doors