2019 LEXUS NX300H engine

3787-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
■If “Traction Battery Needs to be Pro-
tected Refrain From the Use of N Posi-
tion” is shown
This message may be displayed when the
shift lever is in N.
As the hybrid battery (traction battery) can-
not be charged when the shift lever is in N,
when the vehicle is to be stopped for a long
period of time, shift the shift lever to P.
■If “Traction battery needs to be pro-
tected. Shift into P to restart.” is shown
Message is displayed when the remaining
charge for the hybrid battery (traction bat-
tery) is low, because vehicle has been
shifted N for a long period of time.
When operating the vehicle, restart the
hybrid system.
■If “Shift to P Before Exiting Vehicle” is
shown
Message is displayed when the driver’s
door is opened with out turning the power
switch to OFF with the shift lever in any
position other than P.
Shift the shift lever to P.
■If “Shift Is in N Release Accelerator
Before Shifting” is shown
Message is displayed when the accelerator
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 “Front Camera Unavailable” or “Front
Camera Unavailable Remove Debris
On Windshield” is shown
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.208, 369)
●PCS (Pre-Collision System)
●LDA (Lane Departure Alert with steering
control)
●Dynamic radar cruise control with full-
speed range
●Adaptive High-beam System
●Automatic High Beam
■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.330)
■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.330)
■If “See Owner’s Manual” is shown
●If the following messages are shown, fol-
lowing the instruct ions, accordingly.
• “Engine Coolant Temp High” ( P.396)
• “Aux Battery Low” ( P.377)
●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 “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 (traction battery) are dirty, perform the
procedure on P. 316 to clean them.
• If the warning message is shown when

3857-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
7
When trouble arises
4 Lower the vehicle.
5 Firmly tighten each wheel nut two
or three times in the order shown in
the illustration.
Tightening torque:
76 ft•lbf (103 N•m, 10.5 kgf•m)
6Stow the flat tire, tire jack and all
tools.
■The compact spare tire
●The compact spare tire is identified by the
label “TEMPORARY USE ONLY” on
the tire sidewall.
Use the compact spare tire temporarily,
and only in an emergency.
●Make sure to check the tire inflation pres-
sure of the compact spare tire. ( P.408)
■After completing the tire change
The tire pressure warning system must be
reset. ( P.343)
■When using the compact spare tire
As the compact spare tire is not equipped
with a tire pressure warning valve and trans-
mitter, low inflation pressure of the spare
tire will not be indicated by the tire pressure warning system. Also, if you replace the
compact spare tire afte
r 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 spare tire compared to
when driving with standard tires.
■If you have a flat front 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 sp are tire provided
is specifically designed 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 br aking and shifting
operations that cause sudden engine
braking.

3927-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
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.
1Confirm 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.326) 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

3937-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_en
7
When trouble arises
5 Connect a positive jumper cable clamp to on your vehicle and connect the
clamp on the other end of the positive cab le to on the second vehicle. Then,
connect a negative cable clamp to on the second vehicle and connect the
clamp at the other end of the negative cable to .
Exclusive jump starting terminal (your vehicle)
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 vehicle. Increase the engine speed slightly and
maintain at that level for approximatel y 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
7 Open and close any of the doors of yo ur 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 termin al 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.A
B
C
D
A
B
C
D

3967-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_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 and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4
The 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
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
The needle of the engine coolant
temperature gauge ( P.79)
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
A
B
A
B
C

3977-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
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7
When trouble arises
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.
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 (radiato r) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4 The 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.
A
B
A
B
C

3987-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_M78287_enWater can be used in an emergency if
coolant is unavailable.
6
After 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.
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.
●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 dama ge 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.

4038-1. Specifications
LEXUS NX300h Owners Manu-
al_USA_M78287_en
8
Vehicle specifications
This number is also stamped under the
right-hand front seat.■Engine number
The engine number is stamped on the
engine block as shown.
Front
Engine
Model2.5 L 4-cylinder (2AR-FXE)
Type4-cylinder in line, 4-cycle, gasoline
Bore and stroke3.54  3.86 in. (90.0  98.0 mm)
Displacement152.2 cu.in. (2494 cm3)
Valve clearance (engine cold)Automatic adjustment
Drive belt tensionAutomatic adjustment
Fuel
Fuel typeUnleaded gasoline only
Octane Rating87 (Research Octane Number 91) or higher
Fuel tank capacity (Reference)14.8 gal. (56 L, 12.3 Imp.gal.)
Electric motor (traction motor)
TypePermanent magnet synchronous motor
Maximum output105 kW
Maximum torque199 ft•lbf (270 N•m, 27.5 kgf•m)