2021 LEXUS NX300h stop start

4007-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
pedal 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 a message that indicates the malfunc-
tion of front camera is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.209, 391)
●PCS (Pre-Collision System)
●LTA (Lane Tracing Assist) (if equipped)
●LDA (Lane Departure Alert with steering
control) (if equipped)
●Automatic High Beam
●RSA (Road Sign Assist) (if equipped)
●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.209)
■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.350)
■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.350)
■If “See Owner’s Manual” is shown
●If the following messages are shown, fol-
lowing the instruct ions, accordingly.
• “Engine Coolant Temp High” ( P.418)
●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.414).
*: 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

4137-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_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

4187-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
■“Engine Coolant Temp High” is
shown on the multi-information dis-
play
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When exchanging the 12-volt battery
After exchanging, securely attach the
exhaust hose and exhaust hole plug to
the exhaust hole of the exchanged 12-
volt battery. If not properly installed,
gases (hydrogen) may leak into the vehi-
cle interior, and there is the possible dan-
ger of the gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.84)
enters the red zone, or a loss of
hybrid system power is experi-
enced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High” or
“Hybrid System Overheated” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures

4197-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
7
When trouble arises
and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
6
Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the hybrid system immediately
and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8 Check if “Engine Coolant Temp
High” is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact
your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
A
B
A
B
C

4207-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
■If “Hybrid System Overheated” is
shown on the multi-information dis-
play
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood.
3 After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6After stopping the hybrid system
and waiting for 5 minutes or more,
start the hybrid system again and
check if “Hybrid System Over-
heated” is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact your
Lexus dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be driven
normally.
However, if the message appears again fre-
quently, contact your Lexus dealer.
A
B
A
B
C
WARNING
■To prevent an accident or injury when
inspecting under the hood of your
vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

4217-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78578_en
7
When trouble arises
1Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2 Remove the mud, snow or sand
from around the front wheels.
3 Place wood, stones or some other
material under the front wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift lever to D or R,
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press to turn off TRAC. ( P.273)
WARNING
●After the hybrid system has been
turned off, check that the “READY”
indicator is off. When the hybrid sys-
tem is operating, the gasoline engine
may automatically start, or the cooling
fan may suddenly operate even if the
gasoline engine stops. Do not touch or
approach rotating parts such as the
fan, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muf-
fler) getting caught, resulting in serious
injury.
●Do not loosen the coolant reservoir
cap while the hybrid system and radia-
tor are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid
system.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust
etc.).
●Do not use any coolant additive.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

LEXUS NX300h Owners Manual_USA_M78578_en
469What to do if... (Troubleshooting)
Is the power switch in ON mode?
If you cannot release the shift lever
by depressing the brake pedal with
the power switch in ON mode
( P.181)
 It is locked automatically to prevent
theft of the vehicle. ( P.175)
 Is the window lock switch pressed?
The power window except for the
one at the driver’s seat cannot be
operated if the window lock switch
is pressed. ( P.149)
 The auto power off function will be
operated if the vehicle is left in
ACCESSORY or ON mode (the
hybrid system is not operating) for a
period of time. ( P.177)
 The seat belt reminder light is flash-
ing
Are the driver and the passengers wearing the seat belts? (
P.393)
 The parking brake indicator is on
Is the parking brake released?
( P.184)
Depending on the situation, other
types of warning buzzer may also
sound. ( P.388, 398)
 Did anyone inside the vehicle open
a door during setting the alarm?
The sensor detects it and the alarm
sounds. ( P.77)
To stop the alarm, turn the power
switch to ON mode or start the hybrid
system.
 Is the message displayed on the
multi-information display?
Check the message on the multi-
information display. ( P.398)
 When a warning light turns on or a
warning message is displayed, refer
to P.388, 398.
The shift lever cannot be shifted
from P even if you depress the
brake pedal
The steering wheel cannot be
turned after the hybrid system is
stopped
The windows do not open or
close by operating the power
window switches
The power switch is turned off
automatically
A warning buzzer sounds during
driving
An alarm is activated and the
horn sounds
A warning buzzer sounds when
leaving the vehicle
A warning light turns on or a
warning message is displayed

474Alphabetical Index
LEXUS NX300h Owners Manual_USA_M78578_en
Replacing the battery...............................369
Electronically Controlled Brake System (ECB) .............................................................272
Emergency flashers ....................................380
Emergency, in case of If a warning buzzer sounds ................. 388
If a warning light turns on ..................... 388
If a warning message is displayed.....398
If the 12-volt battery is discharged ...... 414
If the electronic key does not operate properly......................................................... 412
If the fuel filler door cannot be opened .............................................................................411
If the hybrid system will not start ........409
If the vehicle is trapped in rising water .......................................................................... 381
If you have a flat tire .................................. 402
If you lose your keys.....................................411
If you think something is wrong .........386
If your vehicle becomes stuck............... 421
If your vehicle has to be stopped in an
emergency ............................................... 380
If your vehicle needs to be towed .....383
If your vehicle overheats ......................... 418
Energy monitor ............................................... 99
Engine .............................................................. 425 Accessory mode ......................................... 177
Compartment .............................................348
Engine switch................................................. 174
Hood................................................................ 346
How to start the hybrid system ............ 174
Identification number ............................... 425
If your vehicle has to be stopped in an
emergency ............................................... 380
Ignition switch (power switch) .............. 174
Overheating.................................................. 418
Power switch ................................................. 174
Engine compartment cover .................... 349
Engine coolant Capacity ......................................................... 427
Checking .........................................................351
Preparing and checking before winter .......................................................................... 279
Warning light .............................................. 389
Engine coolant temperature gauge ....... 84
Engine oil Capacity ......................................................... 426
Checking .......................................................349
Warning light .............................................. 389
Engine switch .................................................. 174
EPS (Electronic Power Steering) Function .......................................................... 272
Warning light .............................................. 390
EV drive mode................................................178
EV indicator ...................................................... 68
Event data recorder (E DR) ........................... 8
F
Flat tire ............................................................. 402
Tire pressure warning system ............ 359
Floor mats .......................................................... 24
Fluid Brake ................................................................ 429
Transmission.................................................428
Washer ...........................................................353
Fog lights Replacing light bulbs ................................375
Switch................................................................ 196
Front passenger occupant classification system ................................................................ 41
Front passenger’s seat belt reminder light .......................................................................... 393
Front seat heaters........................................300
Front seats ........................................................132 Adjustment ......................................................132
Cleaning .........................................................335
Correct driving posture ............................ 25
Driving position memory ........................ 138
Head restraints............................................... 141
Power easy access system .................... 138
Seat heaters ................................................. 300
Seat position memory .............................. 138
Front side marker lights Light switch .................................................... 190