2018 LEXUS NX300h key battery

3476-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manu-
al_USA_OM78212U 6
Maintenance and care 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.
1 Take out the mechanical key.
2 Remove the cover. To prevent damage to the key, cover the tip 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
Replacing the battery

348 6-3. Do-it-yourself maintenance
LEXUS NX300h Owners Manu-
al_USA_OM78212U of the flathead screwdriver with a tape.
3 Remove the depleted battery.Insert a new battery with the “+” terminal
facing up.
■
When the card key battery needs to be
replaced (if equipped)
The battery for th e 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 syst em with push-but-
ton start and wireless remote control will
not function properly.
●
The operational rang e will be reduced.
WARNING
■
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.

357
LEXUS NX300h Owners Manu-
al_USA_OM78212U 7 7
When trouble arises When trouble arises7-1. Essential information
Emergency flashers.................. 358
If your vehicle has to be stopped in
an emergency .......................... 358
7-2. Steps to take in an emergency
If your vehicle needs to be towed
........................................................ 360
If you think something is wrong
........................................................ 363
If a warning light turns on or a
warning buzzer sounds ....... 365
If a warning message is displayed
........................................................ 374
If you have a flat tire.................. 377
If the hybrid system will not start
........................................................ 385
If you lose your keys ................. 386
If the fuel filler door cannot be
opened........................................ 387
If the electronic key does not
operate properly .................... 387
If the 12-volt battery is discharged
........................................................ 390
If your vehicle overheats ........ 394
If the vehicle becomes stuck 397

3857-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 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.387)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle. ( → P.64)
 There may be a malfunction in the
immobilizer system. ( → P.69)
 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.385) One of the following may be the cause
of the problem:
 The 12-volt battery may be dis-
charged. ( → P.390)
 The 12-volt battery terminal con-
nections may be lo ose or corroded.
( → P.333)
One of the following may be the cause
of the problem:
 The 12-volt battery may be dis-
charged. ( → P.390)
 One or both of the 12-volt battery
terminals may be disconnected.
( → P.333) Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the hybrid syst em 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.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.168) 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

3877-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 7
When trouble arises 1 Remove 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 mo de is set. If it is
set, cancel the function. ( → P.123)
Use the mechanical key ( → P.104) to
perform the following operations.If the fuel filler door cannot
be 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
operate properly If communication between the
electronic key and vehicle is inter-
rupted ( → P.123) 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

3897-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 7
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. ( → P.347)
■
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)

390 7-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 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.72) 2 Open the hood ( → P.325) and fuse
box cover.
3 Open the exclusive jump starting
terminal cover.
4 Remove the engine cover.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

392 7-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U ■
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.
●
The power back door mu st be initialized.
( → P.110) ■
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
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