2021 LEXUS NX300h warning

2184-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
*:If equipped
When driving on highways and free-
ways with white (yellow) lane lines, this
function alerts the driver when the
vehicle might depart from its lane or
course
* and provides assistance by
operating the steering wheel to keep
the vehicle in its lane or course
*. Fur-
thermore, the system provides steering
assistance when dynamic radar cruise
control with full-speed range is operat-
ing to keep the vehicle in its lane.
The LTA system recognizes white (yel-
low) lane lines or a course
* using the
front camera. Additionally, it detects
preceding vehicles using the front
camera and radar.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
LTA (Lane Tracing Assist)*
Summary of functions
WARNING
■Before using LTA system
●Do not rely solely upon the LTA sys-
tem. The LTA system does not auto-
matically drive the vehicle or reduce
the amount of attention that must be
paid to the area in front of the vehicle.
The driver must always assume full
responsibility for driving safely by pay-
ing careful attention to the surround-
ing conditions and operating the
steering wheel to correct the path of
the vehicle. Also, the driver must take
adequate breaks when fatigued, such
as from driving for a long period of
time.
●Failure to perform appropriate driving
operations and pay careful attention
may lead to an accident, resulting in
death or serious injury.
●When not using the LTA system, use
the LTA switch to turn the system off.
■Situations unsuitable for LTA system
In the following situations, use the LTA
switch to turn the system off. Failure to do
so may lead to an accident, resulting in
death or serious injury.
●Vehicle is driven on a road surface
which is slippery due to rainy weather,
fallen snow, freezing, etc.
●Vehicle is driven on a snow-covered
road.
●White (yellow) lines are difficult to see
due to rain, snow, fog, dust, etc.
●Vehicle is driven in a temporary lane or
restricted lane due to construction
work.
●Vehicle is driven in a construction
zone.
●A spare tire, tire chains, etc. are
equipped.
●When the tires have been excessively
worn, or when the tire inflation pres-
sure is low.

2194-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
4
Driving
WARNING
●When tires of a size other than speci-
fied are installed.
●Vehicle is driven in traffic lanes other
than that highways and freeways.
●When your vehicle is towing a trailer
or during emergency towing.
■Preventing LTA system malfunctions
and operations performed by mistake
●Do not modify the headlights or place
stickers, etc. on the surface of the
lights.
●Do not modify the suspension etc. If
the suspension etc. needs to be
replaced, contact your Lexus dealer.
●Do not install or place anything on the
hood or grille. Also, do not install a
grille guard (bull bars, kangaroo bar,
etc.).
●If your windshield needs repairs, con-
tact your Lexus dealer.
■Conditions in which functions may
not operate properly
In the following situations, the functions
may not operate properly and the vehicle
may depart from its lane. Drive safely by
always paying careful attention to your
surroundings and operate the steering
wheel to correct the path of the vehicle
without relying solely on the functions.
●When the follow-up cruising display is
displayed ( P.223) and the preced-
ing vehicle changes lanes. (Your vehi-
cle may follow the preceding vehicle
and also change lanes.)
●When the follow-up cruising display is
displayed ( P.223) and the preced-
ing vehicle is swaying. (Your vehicle
may sway accordingly and depart from
the lane.)
●When the follow-up cruising display is
displayed ( P.223) and the preced-
ing vehicle departs from its lane. (Your
vehicle may follow the preceding vehi-
cle and depart from the lane.)
●When the follow-up cruising display is
displayed ( P.223) and the preced-
ing vehicle is being driven extremely
close to the left/right lane line. (Your
vehicle may follow the preceding vehi-
cle and depart from the lane.)
●Vehicle is being driven around a sharp
curve.
●Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of the road (guardrails,
reflective poles, etc.).

2204-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
WARNING
●Vehicle is driven where the road
diverges, merges, etc.
●Repair marks of asphalt, white (yellow)
lines, etc. are present due to road
repair.
●There are shadows on the road that
run parallel with, or cover, the white
(yellow) lines.
●The vehicle is driven in an area without
white (yellow) lines, su ch as in front of a
tollgate or checkpoint, or at an inter-
section, etc.
●The white (yellow) lines are cracked,
“Botts’ dots”, “Raised pavement
marker” or stones are present.
●The white (yellow) lines cannot be
seen or are difficult to see due to sand,
etc.
●The vehicle is driven on a road surface
that is wet due to rain, puddles, etc.
●The traffic lines are yellow (which may
be more difficult to recognize than
lines that are white).
●The white (yellow) lines cross over a
curb, etc.
●The vehicle is driven on a bright sur-
face, such as concrete.
●If the edge of the road is not clear or
straight.
●The vehicle is driven on a surface that
is bright due to reflected light, etc.
●The vehicle is driven in an area where
the brightness change s suddenly, such
as at the entrances and exits of tunnels,
etc.
●Light from the headlights of an oncom-
ing vehicle, the sun, etc. enters the
camera.
●The vehicle is driven on a slope.
●The vehicle is driven on a road which
tilts left or right, or a winding road.
●The vehicle is driven on an unpaved or
rough road.
●The traffic lane is excessively narrow
or wide.
●The vehicle is extremely tilted due to
carrying heavy luggage or having
improper tire pressure.
●The distance to the preceding vehicle
is extremely short.
●The vehicle is moving up and down a
large amount due to road conditions
during driving (poor roads or road
seams).
●When driving in a tunnel or at night
with the headlights off or when a head-
light is dim due to its lens being dirty or
it being misaligned.
●The vehicle is struck by a crosswind.

2214-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
4
Driving
■Lane departure alert function
When the system determines that the
vehicle might depart from its lane or
course
*, a warning is displayed on the
multi-information display, and either a
warning buzzer will sound or the steer-
ing wheel will vibrate to alert the driver.
When the warning buzzer sounds or the
steering wheel vibrates, check the area
around your vehicle and carefully operate
the steering wheel to move the vehicle
back to the center of the lane.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
■Steering assist function
When the system determines that the
vehicle might depart from its lane or
course
*, the system provides assis-
tance as necessary by operating the
steering wheel in small amounts for a
short period of time to keep the vehicle
in its lane.
If the system detects that the steering
wheel has not been operated for a fixed
amount of time or the steering wheel is not
being firmly gripped, a warning is displayed
on the multi-informat ion display and the
function is temporarily canceled.
*: Boundary between asphalt and the side of the road, such as grass, soil, or a curb
WARNING
●The vehicle is affected by wind from a
vehicle driven in a nearby lane.
●The vehicle has just changed lanes or
crossed an intersection.
●Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●Snow tires, etc. are equipped.
●The vehicle is being driven at
extremely high speeds.
Functions included in LTA system

2224-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
■Vehicle sway warning function
When the vehicle is swaying within a
lane, the warning buzzer will sound and
a message will be displayed on the
multi-information display to alert the
driver.
■Lane centering function
This function is linked with dynamic
radar cruise control with full-speed
range and provides the required assis-
tance by operating the steering wheel
to keep the vehicle in its current lane.
When dynamic radar cruise control with
full-speed range is not operating, the lane
centering function does not operate.
In situations where the white (yellow) lane
lines are difficult to see or are not visible,
such as when in a traffic jam, this function
will operate to help follow a preceding
vehicle by monitoring the position of the
preceding vehicle.
If the system detects that the steering
wheel has not been operated for a fixed
amount of time or the steering wheel is not
being firmly gripped, a warning is displayed
on the multi-informat ion display and the
function is temporarily canceled.

2254-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
4
Driving
lowing conditions are met in addition to the
operation conditions for the lane departure
alert function.
•Setting for “Steering Assist” in of the
multi-information display is set to “On”.
( P. 89)
• Vehicle is not accelerated or decelerated
by a fixed amount or more.
• Steering wheel is not operated with a
steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper-
ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. ( P.226)
●Vehicle sway warning function
This function operates when all of the fol-
lowing conditions are met.
• Setting for “Sway Warning” in of the
multi-information display is set to “On”.
( P.89)
• Vehicle speed is approximately 32 mph
(50 km/h) or more.
• Width of traffic lane is approximately 9.8
ft. (3 m) or more.
• No system malfunctions are detected. ( P.226)
●Lane centering function
This function operates when all of the fol-
lowing conditions are met.
• LTA is turned on.
• Setting for “Steering Assist” and “Lane
Center” in of th e multi-information
display are set to “On”. ( P.89)
• This function recognizes white (yellow)
lane lines or the position of a preceding
vehicle (except when the preceding vehi-
cle is small, such as a motorcycle).
• The dynamic radar cruise control with full-speed range is operating in vehicle-
to-vehicle distance control mode.
• Width of traffic lane is approximately 10 to 13 ft. (3 to 4 m).
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (
 P.226)
• Vehicle does not ac celerate or deceler-
ate by a fixed amount or more.
• Steering wheel is not operated with a steering force level su itable for changing
lanes.
• ABS, VSC, TRAC and PCS are not oper- ating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not
displayed. ( P.226)
• The vehicle is being driven in the center
of a lane.
• Steering assist function is not operating.
■Temporary cancelation of functions
●When operation condit ions are no longer
met, a function may be temporarily can-
celed. However, when the operation con-
ditions are met again, operation of the
function is automatically restored.
(  P.224)
●If the operation conditions ( P.224) are
no longer met while the lane centering
function is operating, the steering wheel
may vibrate and the buzzer may sound to
indicate that the function has been tem-
porarily canceled. Howe ver, if the “Alert”
customization setting is set to ,
the system will notify the driver by vibrat-
ing the steering whee l instead of sound-
ing the buzzer.
■Steering assist function/lane centering
function
●Depending on the vehicle speed, lane
departure situation, road conditions, etc.,
the driver may not feel the function is
operating or the function may not oper-
ate at all.
●The steering control of the function is
overridden by the driver’s steering wheel
operation.
●Do not attempt to test the operation of
the steering assist function.
■Lane departure alert function
●The warning buzzer may be difficult to
hear due to external noise, audio play-
back, etc. Also, it may be difficult to feel
steering wheel vibrations due to the road

2264-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
conditions, etc.
●If the edge of the course* is not clear or
straight, the lane departure alert function
may not operate.
●Do not attempt to test the operation of
the lane departure alert function.
*: Boundary between asphalt and the side
of the road, such as grass, soil, or a curb
■Hands off steering wheel warning
In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol shown in the illustra-
tion are displayed on the multi-information
display to warn the driver. The warning
stops when the system determines that the
driver holds the steering wheel. Always
keep your hands on the steering wheel
when using this system, regardless of warn-
ings.
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the sy stem is operating
If the driver continue s to keep their hands
off of the steering wheel, the buzzer sounds,
the driver is warned and the function is tem-
porarily canceled. This warning also oper-
ates in the same way when the driver
continuously operates the steering wheel
only a small amount.
The buzzer also sounds even if the alert
type is set to .
●When the system determines that the
vehicle may not turn and instead depart
from its lane while driving around a curve
Depending on the vehicle condition and
road conditions, the warning may not oper-
ate. Also, if the system determines that the vehicle is driving around a curve, warnings
will occur earlier than
during straight-lane
driving.
●When the system determines that the
driver is driving with out holding the steer-
ing wheel while the st eering wheel assist
of the steering assist function is operat-
ing.
If the driver continues to keep their hands
off of the steering wheel and the steering
wheel assist is operatin g, the buzzer sounds
and the driver is warned. Each time the
buzzer sounds, the continuing time of the
buzzer becomes longer.
The buzzer also sounds even if the alert
type is set to .
■Vehicle sway warning function
When the system determines that the vehi-
cle is swaying while the vehicle sway warn-
ing function is operating, a buzzer sounds
and a warning message urging the driver to
rest and the symbol sh own in the illustration
are simultaneously di splayed on the multi-
information display.
Depending on the vehicle and road condi-
tions, the warning may not operate.
■Warning message
If the following warning message is dis-
played on the multi-in formation display and
the LTA indicator illuminates in orange, fol-
low the appropriate troubleshooting proce-
dure. Also, if a different warning message is
displayed, follow the instructions displayed
on the screen.
●“LTA Malfunction Visit Your Dealer”
The system may not be operating properly.
Have the vehicle inspected by your Lexus

2284-5. Using the driving support systems
LEXUS NX300h Owners Manual_USA_M78578_en
WARNING
■Before using LDA system
●Do not rely solely upon the LDA sys-
tem. The LDA system does not auto-
matically drive the vehicle or reduce
the amount of attention that must be
paid to the area in front of the vehicle.
The driver must always assume full
responsibility for driving safely by pay-
ing careful attention to the surround-
ing conditions and operating the
steering wheel to correct the path of
the vehicle. Also, the driver must take
adequate breaks when fatigued, such
as from driving for a long period of
time.
●Failure to perform appropriate driving
operations and pay careful attention
may lead to an accident, resulting in
death or serious injury.
●When not using the LDA system, use
the LDA switch to turn the system off.
■Situations unsuitable for LDA system
In the following situations, use the LDA
switch to turn the system off. Failure to do
so may lead to an acc ident, resulting in
death or serious injury.
●Vehicle is driven on a road surface
which is slippery due to rainy weather,
fallen snow, freezing, etc.
●Vehicle is driven on a snow-covered
road.
●White (yellow) lines are difficult to see
due to rain, snow, fog, dust, etc.
●A spare tire, tire chains, etc. are
equipped.
●When the tires have been excessively
worn, or when the tire inflation pres-
sure is low.
●When tires of a size other than speci-
fied are installed.
●Vehicle is driven in traffic lanes other
than that highways and freeways.
●When your vehicle is towing a trailer
or during emergency towing.
■Preventing LDA system malfunctions
and operations performed by mistake
●Do not modify the headlights or place
stickers, etc. on the surface of the
lights.
●Do not modify the su spension, etc. If
the suspension, etc. needs to be
replaced, contact your Lexus dealer.
●Do not install or place anything on the
hood or grille. Also, do not install a
grille guard (bull bars, kangaroo bar,
etc.).
●If your windshield needs repairs, con-
tact your Lexus dealer.
■Conditions in which functions may
not operate properly
In the following situations, the functions
may not operate properly and the vehicle
may depart from its la ne. Drive safely by
always paying careful attention to your
surroundings and operate the steering
wheel to correct the path of the vehicle
without relying solely on the functions.
●Vehicle is being driven around a sharp
curve.
●Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of the road (guardrails,
reflective poles, etc.).