2020 LEXUS NX300h ECU

3817-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
7-2.Steps to take in an emergency
If your vehicle needs to be
towed
If towing is ne cessary, we recom-
mend having your vehicle towed by
your Lexus dealer or commercial
towing service, using a wheel-lift
type truck or flatbed truck.
Use a safety chain system for all
towing, and abide by all state/pro-
vincial and local laws.
If towing your vehicle with a wheel-
lift type truck, use a towing dolly.
(  P.381, 382)
WARNING
Observe the following precautions.
Failure to do so may result in death or
serious injury.
■When towing the vehicle
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.
■While towing
●When towing using a cables or chains,
avoid sudden starts, etc. which place
excessive stress on the towing eyelets,
cables or chains. The towing eyelets,
cables or chains may become dam-
aged, 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 oper-
ated.
■Installing towing eyelets to the vehi-
cle
Make sure that towing eyelets are
installed securely.
If not securely installed, towing eyelets
may come loose during towing.
NOTICE
■To prevent damage to the vehicle
when towing using a wheel-lift type
truck
●Do not tow the vehicle from the rear
when the power switch is off. The
steering lock mechanism is not strong
enough to hold the front wheels
straight.
●When raising the vehicle, ensure ade-
quate ground clearance for towing at
the opposite end of the raised vehicle.
Without adequate clearance, the vehi-
cle could be damaged while being
towed.
■To prevent damage to the vehicle
when towing with a sling-type truck
Do not tow with a sling-type truck, either
from the front or rear.

3837-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
7
When trouble arises
If you use chains or cables to tie down
your vehicle, the angles shaded in
black must be 45°.
Do not overly tighten the tie downs or
the vehicle may be damaged.
If a tow truck is not available in an
emergency, your vehicle may be tem-
porarily towed using cables or chains
secured to the emergency towing eye-
lets. This should only be attempted on
hard surfaced roads for a short dis-
tance at under 18 mph (30 km/h).
A driver must be in the vehicle to steer
and operate the brakes. The vehicle’s
wheels, drivetrain, ax les, steering and
brakes must be in good condition.
To have your vehicle towed by another vehicle, the towing eyelet must be
installed to your vehicle. Install the tow-
ing eyelet by following the specified
procedure.
1
Take out the towing eyelet.
(P.400)
2 Remove the eyelet cover using a
flathead screwdriver.To protect the bodywork, place a rag
between the screwdriver and the vehicle
body as shown in the illustration.
3Insert the towing eyelet into the
hole and tighten partially by hand.
Emergency towing procedure
To have your vehicle towed

3847-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
4Tighten down the towing eyelet
securely using a wheel nut wrench.
5 Securely attach cables or chains to
the towing eyelet.
Take care not to damage the vehicle body.
6Enter the vehicle being towed and
start the hybrid system.
If the hybrid system does not start, turn the
power switch to ON mode.
7Shift the shift lever to N and release
the parking brake.
When the shift lever cannot be shifted:
P.180
■While towing
If the hybrid system is off, the power assist
for the brakes and steering will not function,
marking steering and braking more difficult.
■Wheel nut wrench
Wheel nut wrench is installed in luggage
compartment. ( P.400)
 Fluid leaks under the vehicle
(Water dripping from the air condi-
tioning after use is normal.)
 Flat-looking tires or uneven tire
wear
 Engine coolant temperature gauge
needle continually points higher
than normal
 Changes in exhaust sound
 Excessive tire squeal when corner-
ing
 Strange noises related to the sus-
pension system
 Pinging or other noises related to
the hybrid system
 Engine misfire or misses, stumbling
or running roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking
If you think something is
wrong
If you notice any of the following
symptoms, your vehicle probably
needs adjustment or repair. Con-
tact your Lexus dealer as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms

3937-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_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 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.
Warning lightDetails/Actions
Brake Override System
Indicates that the accelerato r and brake pedals are being
depressed simultaneously, and the Brake Override System
is operating.
 Release the accelerator pedal 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 accelera-
tor pedal. (with warning buzzer)
 Momentarily release th e accelerator pedal.
Indicates a malfunction in th e Drive-Start Control system
(with warning buzzer)
 Have the vehicle inspected by your Lexus dealer
immediately.

4027-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_en
4Use the hook to secure the deck
board as shown in the illustration.
5 Removing the Jack.
1 Remove the rubber band.
2 Remove the cover and the jack.
When stowing the jack, close it by turning
the handle indicated by until it does not
move anymore, stow the jack and the
cover, and press on the jack to fix with the
rubber band.
1 Remove deck under tray.
2 Loosen the center fastener that
secures the spare tire.
1 Chock the tires.
A
Taking out the spare tire
WARNING
■When storing the spare tire
Be careful not to catch fingers or other
body parts between the spare tire and
the body of the vehicle.
Replacing a flat tire

4067-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_enwarning system. Also, if you replace the
compact spare tire after the tire pressure
warning light comes on, the light remains
on.
■When the compact spare tire is
equipped
The vehicle becomes lower when driving
with the compact spar e tire compared to
when driving with standard tires.
■If you have a flat fron t tire on a road cov-
ered with snow or ice
Install the compact spare tire on one of the
rear wheels of the vehicle. Perform the fol-
lowing steps and fit tire chains to the front
tires:
1 Replace a rear tire with the compact
spare tire.
2 Replace the flat front tire with the tire
removed from the rear of the vehicle.
3 Fit tire chains to the front tires.
WARNING
■When using the compact spare tire
●Remember that the spare tire provided
is specifically desi gned for use with
your vehicle. Do not use your spare
tire on another vehicle.
●Do not use more than one spare tire
simultaneously.
●Replace the spare tire with a standard
tire as soon as possible.
●Avoid sudden acceleration, abrupt
steering, sudden braking and shifting
operations that cause sudden engine
braking.
■When the compact spare tire is
attached
The vehicle speed may not be correctly
detected, and the following systems may
not operate correctly:
• ABS & Brake assist
•VSC
•TRAC
• Dynamic radar cruise control with full- speed range
• PCS (Pre-Collision System)
•EPS
• LTA (Lane Tracing Assist) (if equipped)
• LDA (Lane Departure Alert with steering control) (if equipped)
• Panoramic view monitor (if equipped)
• Lexus parking assist monitor (if equipped)
• Intuitive parking assist (if equipped)
• Navigation system (if equipped)
• BSM (Blind spot monitor) (if equipped)
• Automatic high Beam (if equipped)
Also, not only can the following system
not be utilized fully, bu t it may even nega-
tively affect the drive-train components:
•E-Four
■Speed limit when using the compact
spare tire
Do not drive at speeds in excess of 50
mph (80 km/h) when a compact spare
tire is installed on the vehicle.
The compact spare tire is not designed
for driving at high speeds. Failure to
observe this precaution may lead to an
accident causing death or serious injury.
■After using the tools and jack
Before driving, make sure all the tools
and jack are securely in place in their
storage location to reduce the possibility
of personal injury during a collision or
sudden braking.

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.

4167-2. Steps to take in an emergency
LEXUS NX300h Owners Manual_USA_M78530_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