
5217-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_U_OM78007U ■
Situations in which the tire pressure warning system may not operate properly ●
In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehicle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extremely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer. ●
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility th at generates strong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless ph one or other wireless
communication device ●
When the vehicle is parked, the time taken for the warning to start or go off could be
extended. ●
When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function. ■
The initialization operation ●
Make sure to carry out initialization af ter adjusting the tire inflation pressure.
Also, make sure the tires are cold before carry ing out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the power swit ch off during initializat ion, it is not neces-
sary to press the reset switch again as init ialization will restart automatically when the
power switch has been turned to ON mode for the next time. ●
If you accidentally press the reset switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are co ld, and conduct initial-
ization again. ■
Warning performance of the tire pressure warning system
The warning of the tire pressure warning syst em will change in accordance with the con-
ditions under which it was initialized. For this reason, the system may give a warning even
if the tire pressure does not reach a low enough level, or if the pressure is higher than the
pressure that was adjusted to when the system was initialized. ■
When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases, the set-
tings have not been recorded and the system will not operate properly. If repeated
attempts to record tire inflation pressure settings are unsuccessful, have the vehicle
inspected by your Lexus dealer. ●
When operating the tire pressure warning reset switch, the tire pressure warning light
does not blink 3 times. ●
After carrying out the initializ ation procedure, the tire pres sure warning light blinks for
1 minute then stays on after driving for 20 minutes.

5237-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_U_OM78007U WA R N I N G ■
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resultin g in death or serious injury.●
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear. ●
Do not use tire sizes other than those recommended by Lexus. ●
Do not mix differently constructed tires (radial, bias-belted or bias-ply tires). ●
Do not mix summer, all season and snow tires. ●
Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously. ●
Vehicles with a compact spare tire: Do no t tow if your vehicle has a compact spare
tire installed. ■
When initializing the tire pressure warning system
Do not initializing tire inflation pressure wi thout first adjusting the tire inflation pressure
to the specified level. Otherwise, the tire pressure warning light may not come on even
if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal. ■
Caution regarding interference with electronic devices
●
Users of any electrical medical device other than implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemakers or implantable cardioverter defibril-
lators should consult the ma nufacturer of the device for information about its opera-
tion under the influence of radio waves.
Radio waves could have unexpected effe cts on the operation of such medical
devices. ●
People with implantable cardiac pacemakers,
cardiac resynchronization therapypacemak-
ers or implantable cardioverter defibrillators
should not come within 17.7 in. (450 mm) of
the tire pressure warning system initiators.
The radio waves may affect the operation of
such devices.

558 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf your vehicle needs to be towed
The following may indicate a problem with your hybrid transmission. Contact
your Lexus dealer or commercial towing service before towing. ( P. 5 6 2 )●
The hybrid warning message shows on and the vehicle does not move. ●
The vehicle makes an abnormal sound.
Do not tow with a sling-type truck to
prevent body damage.If towing is necessary, we recommend having your vehicle towed by your
Lexus dealer or a commercial towing service, using a lift-type truck or flat bed
truck.
Use a safety chain system for all towing, and abide by all state/provincial and
local laws.
2WD models: If towing your vehicle with a wheel-lift type truck from the front,
the vehicle’s rear wheels and axles must be in good conditions. ( P. 559, 562)
If they are damaged, use a towing dolly or flatbed truck.
AWD models: If towing your vehicle with a wheel-lift type truck, use a towing
dolly. ( P. 559, 562)
Situations needs to contact dealers before towing
Towing with a sling-type truck

562 8-2. Steps to take in an emergency
NX300h_U_OM78007U WA R N I N G
Observe the following precautions.
Failure to do so may result in death or serious injury. ■
When transporting the vehicle
2WD models
AW D m o d e l s
■
While towing ●
When towing using a cables or chains, avoid sudden starts, etc. which place excessive
stress on the towing hook and rope. The towing hook or rope may become damaged,
broken debris may hit people and cause serious damage. ●
Do not turn the power switch off.
There is a possibility that the steering wheel is locked and cannot be operated.■
Installing towing eyelets to the vehicle
Make sure that towing eyelets are installed securely.
If not securely installed, towing ey elets may come loose during towing.Be sure to transport the vehicle with the front
wheels raised or with all four wheels raised off
the ground. If the vehicle is towed with the front
wheels contacting the ground, the drivetrain
and related parts may be damaged or electric-
ity generated by the operation of the motor
may cause a fire to occur depending on the
nature of the damage or malfunction.
Be sure to transport the vehicle with all four
wheels raised off the ground. If the vehicle is
towed with the tires contacting the ground, the
drivetrain or related parts may be damaged,
the vehicle may fly off the truck, or electricity
generated by the operation of the motor may
cause a fire to occur depending on the nature
of the damage or malfunction.

568 8-2. Steps to take in an emergency
NX300h_U_OM78007U * 1
: This light illuminates on the multi-information display.
* 2
: Driver’s and front passenger’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to alert the driver that his or her seat belt
is not fastened. Once the power switch is turned to ON mode, the buzzer sounds for
6 seconds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer sounds
once. If the seat belt is st ill unfastened after 24 second s, the buzzer will sound inter-
mittently for 10 seconds. Then, if the seat be lt is still unfastened, the buzzer will sound
in a different tone for 20 more seconds.
The front passenger’s seat be lt warning buzzer sounds to alert the front passenger
that his or her seat belt is not fastened. The buzzer sounds once if the vehicle reaches
a speed of 12 mph (20 km/h). If the seat belt is still unfastened after 24 seconds, the
buzzer will sound intermittently for 10 seconds. Then, if the seat belt is still unfastened,
the buzzer will sound in a different tone for 20 more seconds. ■
SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front), side impact sensors (r ear), driver’s seat position sensor, driver’s
seat belt buckle switch, front passenger occupant classification system (ECU and sen-
sors), “AIR BAG ON” indicator light, “AIR BAG OFF” indicator light, front passenger’s
seat belt buckle switch, driver’s seat belt pr etensioner, front passenger’s seat belt preten-
sioner and force limiter, airbags, interconnecting wiring and power sources. ( P. 4 0 )■
Front passenger detection sensor, seat belt reminder and warning buzzer●
If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sittin g in the seat.●
If a cushion is placed on th e seat, the sensor may not detect a passenger, and the warn-
ing 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.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.

590 8-2. Steps to take in an emergency
NX300h_U_OM78007U One of the following may be the cause of the problem: ●
The 12-volt battery may be discharged. ( P. 5 9 5 )●
One or both of the 12-volt battery terminals may be disconnected. ( P. 5 1 2 )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 system if the power switch is functioning nor-
mally:
Do not use this starting procedur e except in cases of emergency.
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function 1
2
3
4

594 8-2. Steps to take in an emergency
NX300h_U_OM78007U Press the power switch.
In the event that the hybrid system st ill cannot 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 normally
do when stopping the hybrid system. ■
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediatel y when the battery is depleted. ( P. 5 3 2 )■
Alarm (if equipped)
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 al arm system is set, the alarm may be trig-
gered. ■
Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and mode s will be changed each time the switch is
pressed. ( P. 202)■
When the electronic key does not work properly ●
Make sure that the smart access system wi th push-button start has not been deacti-
vated in the custom ization setting. If it is off, turn the function on.
(Customizable features P. 6 3 5 )●
Check if battery-saving mo de is set. If it is se t, cancel the function. ( P. 1 4 2 )
WA R N I N G ■
When using the mechanical key and operating the power windows or moon roof
Operate the power window or moon roof afte r checking to make sure that there is no
possibility of any passenger having any of their body parts caught in the window or
moon roof.
Also, do not allow children to operate the mech anical key. It is possible for children and
other passengers to get caught in the power window or moon roof. 4
3

5978-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of your vehicle with the power switch off.
Maintain the engine speed of the second vehicle and start the hybrid system
of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light does not
come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Close the exclusive jump starting terminal cover, and reinstall the fuse box
cover to its original position.
Once the hybrid system starts, have th e 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 system while the hybrid system is off. ●
Turn off any unnecessary electrical components 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 discharge and the draining effects of certain electrical appli-
ances. If the vehicle is left for a long time, the 12-volt battery may discharge, 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 mechanical 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 dis-
charged, be especially careful when reconnecting the 12-volt battery. ●
The power back door must be initialized. ( P. 1 3 4 )●
Make sure that the key is not inside the vehicle when recharging or replacing the
12-volt battery. The key may be locked in the vehicle if the alarm is activated. ( P. 88)5
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