2020 LEXUS NX300h battery

3997-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
(traction battery) ar e dirty, perform the
procedure on P.335 to clean them.
• If the warning message is shown when
the air intake vents of the hybrid battery
(traction battery) are not dirty, have the
vehicle inspected by your Lexus dealer.
●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”
■Warning buzzer
 P.394
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 12-volt bat-
tery may be deteriorating. Have the vehi-
cle inspected by your Lexus dealer.
■“Aux Battery Low” is frequently
shown
The 12-volt battery may have deterio-
rated. As the battery may discharge in
this state when left unattended, have the
battery inspected by your Lexus dealer.

4077-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
One of the following may be the cause
of the problem:
 The electronic key may not be func-
tioning properly. ( P.410)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle. ( P.70)
 There may be a malfunction in the
immobilizer system. ( P.75)
 There may be a malfunction in the
steering lock system.
 The hybrid system may be malfunc-
tioning due to an electrical problem
such as electronic key battery
depletion or a blown fuse. However,
depending on the type of malfunc-
tion, an interim measure is available
to start the hybrid system.
( P.408)
NOTICE
■Be careful when driving over bumps
with the compact spare tire installed
on the vehicle
The vehicle becomes lower when driving
with the compact spare tire compared to
when driving with standard tires. Be
careful when driving over uneven road
surfaces.
■Driving with tire chains and the com-
pact spare tire
Do not fit tire chains to the compact
spare tire.
Tire chains may damage the vehicle body
and adversely affect driving perfor-
mance.
■When replacing the tires
When removing or fitting the wheels,
tires or the tire pressure warning valve
and transmitter, contact your Lexus
dealer as the tire pr essure warning valve
and transmitter may be damaged if not
handled correctly.
If the hybrid system will not
start
Reasons for the hybrid system not
starting vary depending on the situ-
ation.
Check the following and perform
the appropriate procedure:
The hybrid system will not start
even though the correct starting
procedure is being followed.
(  P.174)

4087-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
One of the following may be the cause
of the problem:
The 12-volt battery may be dis-
charged. ( P.412)
 The 12-volt battery terminal con-
nections may be loose or corroded.
( P.352)
One of the following may be the cause
of the problem:
 The 12-volt battery may be dis-
charged. ( P.412)
 One or both of the 12-volt battery
terminals may be disconnected.
( P.352)
Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start,
the following steps can be used as an
interim measure to start the hybrid sys-
tem if the power switch is functioning
normally.
Do not use this starting procedure
except in cases of emergency. 1
Set the parking brake.
2 Shift the shift lever to P.
3 Turn the power switch to ACCES-
SORY mode.
4 Press and hold the power switch for
about 15 seconds while depressing
the brake pedal firmly.
Even if the hybrid system can be
started using the above steps, the sys-
tem may be malfunctioning. Have the
vehicle inspected by your Lexus dealer.
The interior lights and head-
lights are dim, or the horn does
not sound or sounds at a low vol-
ume.
The interior lights and head-
lights do not turn on, or the horn
does not sound.
Starting the hybrid system in an
emergency

4107-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
■Things to check before taking measures
●Make sure that the smart access system
with push-button start has not been deac-
tivated in the customization setting. If it is
off, turn the function on.
●Check if battery-saving mode is set. If it is
set, cancel the function. ( P.127)
Use the mechanical key ( P.108) to
perform the following operations.
■Unlocking the door
1 Insert the mechanical key while
pulling on the driver’s door handle.
2 Turn the key in order to perform the
following operations.
Unlocking the door
Opens the windows and moon
roof
* (turn and hold)
Closes the windows and moon
roof
* (turn and hold)
*: This setting must be customized at your Lexus dealer
3 Remove the key, return the handle,
and then pull the handle again.
If the electronic key does not
operate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.128) 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 hybrid
system 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
A
B
C

4117-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
■Locking the door
1 Move the inside lock button to the
lock position.
2 Close the door.
1 Ensure that the shift lever is in P and
depress the brake pedal.
2 Touch the Lexus emblem side of the
electronic key to the power switch.
When the electronic key is detected, a
buzzer sounds and the power switch will
turn to ON mode.
When the smart access system with push-
button start is deactivated in customization
setting, the power switch will turn to 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 recommended that the elec-
tronic key battery be replaced immediately
when the battery is depleted.
■Alarm
Using the mechanical ke y to lock the doors
will not set the alarm system. If a door is
unlocked using the me chanical key when
the alarm system is set, the alarm may be
triggered.
WARNING
■When using the mechanical key and
operating the power windows or
moon roof
Operate the power window or moon
roof after checking to make sure that
there is no possibilit y of any passenger
having any of their body parts caught in
the window or moon roof.
Also, do not allow ch ildren to operate the
mechanical key. It is possible for children
and other passengers to get caught in
the power window or moon roof.
Starting the hybrid system

4127-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
■Changing power switch modes
Release the brake pedal 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.176)
If you have a set of jumper (or booster)
cables and a second vehicle with a 12-
volt battery, you can jump start your
vehicle by following the steps below.
1 Confirm that the electronic key is
being carried.
When connecting the jumper (or booster)
cables, depending on the situation, the
alarm may activate and the doors may lock.
( P.78)
If the 12-volt battery is dis-
charged
The following procedures may be
used to start the hybrid system if the
vehicle’s 12-volt battery is dis-
charged.
You can also call your Lexus dealer
or a qualified repair shop.
Restarting the hybrid system

4147-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic point away from the exclusive jump starting
terminal and any mo ving parts as shown in the illustration
6 Start the engine of the second vehi-
cle. Increase the engine speed
slightly and maintain at that level for
approximately 5 minutes to
recharge the 12-volt battery of your
vehicle.
7 Open and close any of the doors of
your vehicle with the power switch
off.
8 Maintain the engine speed of the
second vehicle and start the hybrid
system of your vehicle by turning
the power switch to ON mode.
9 Make sure the “READY” indicator
comes on. If the indicator light does
not come on, contact your Lexus
dealer.
10 Once the hybrid system has
started, remove the jumper cables
in the exact reverse order from
which they were connected.
11 Close the exclusive jump starting
terminal cover, and reinstall the fuse
box cover to its original position.
Once the hybrid system starts, have
the vehicle inspected at your Lexus
dealer as soon as possible.
■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 gradually 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 batte ry 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 requ ire initialization.
B
C
D

4157-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
■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.
C
A
B
WARNING
■Avoiding 12-volt battery fires or
explosions
Observe the following precautions to
prevent accidentally igniting the flamma-
ble gas that may be emitted from the 12-
volt battery:
●Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentionally in contact with
any other than the intended terminal.
●Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or meta l surfaces in the
area, such as brackets or unpainted
metal.
●Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●Do not smoke, use matches, cigarette
lighters or allow open flame near the
12-volt battery.
■12-volt Battery precautions
The 12-volt battery contains poisonous
and corrosive acidic electrolyte, while
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
●When working with the 12-volt battery,
always wear safety glasses and take
care not to allow any battery fluids
(acid) to come into contact with skin,
clothing or the vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes
into contact with the skin or eyes,
immediately wash the affected area
with water and seek medical attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your ha nds after handling
the 12-volt battery support, terminals,
and other battery-related parts.