LEXUS RC300 2019 Owners Manual

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Driving
■Lane departure alert function
When the system determines that the
vehicle might depart from its lane, a
warning is displayed on the multi-infor-
mation display, and either the warning
buzzer sounds or the steering wheel
vibrates to alert the driver.
When the warning buzzer sounds or the
steering wheel vibrates, check the sur-
rounding road situation and carefully oper-
ate the steering wheel to move the vehicle
back to the center of the lane.
■Steering control function
When the system determines that the
vehicle might depart from its lane, the
system provides assistance as neces-
sary 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.
LDA (Lane Departure Alert
with steering control)
When driving on highways and
freeways with white (yellow) lines,
this function alerts the driver when
the vehicle might depart from its
lane and provides assistance by
operating the steering wheel to
keep the vehicle in its lane.
The LDA system recognizes visible
white (yellow) lines with the camera
sensor on the upper portion of the
front windshield.
Functions included in LDA sys-
tem

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■Vehicle sway warning function
When the vehicle is swaying or
appears as if it may depart from its lane
multiple times, the warning buzzer
sounds and a message is displayed on
the multi-information display to alert
the driver.
WARNING
■Before using LDA system
Do not rely solely upon the LDA system.
The LDA system does not automatically
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 driv-
ing safely by paying careful attention to
the surrounding conditions and operat-
ing 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.
■To avoid operating LDA system by
mistake
When not using the LDA system, use the
LDA switch to turn the system off.
■Situations unsuitable for LDA system
Do not use the LDA system in the follow-
ing situations.
The system may not operate properly
and lead to an accident, resulting in
death or serious injury.
●A spare tire, tire chains, etc. are
equipped.
●When the tires have been excessively
worn, or when the tire inflation pres-
sure is low.
●Tires which differ by structure, manu-
facturer, brand or tread pattern are
used.
●Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of the road (guardrails,
curbs, reflective poles, etc.).
●Vehicle is driven on a snow-covered
road.
●White (yellow) lines are difficult to see
due to rain, snow, fog, dust, etc.

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Press the LDA switch to turn the LDA
system on.
The LDA indicator illuminates and a mes-
sage is displayed on the multi-information
display.
Press the LDA switch again to turn the
LDA system off.
When the LDA system is turned on or off,
operation of the LDA system continues in the same condition the next time the
engine is started.
LDA indicator
The illumination condition of the indicator
informs the driver of the system operation
status.
Illuminated in white:
LDA system is operating.
Illuminated in green:
Steering wheel assistan
ce of the steering
control function is operating.
Flashing in orange:
WARNING
●Asphalt repair marks, white (yellow)
line marks, etc. are present due to road
repair.
●Vehicle is driven in a temporary lane or
restricted lane due to construction
work.
●Vehicle is driven on a road surface
which is slippery due to rainy weather,
fallen snow, freezing, etc.
●Vehicle is driven in traffic lanes other
than on highways and freeways.
●Vehicle is driven in a construction
zone.
●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 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.
Turning LDA system on
Indications on multi-information
display
A

1644-5. Using the driving support systems
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0_OM_(U)_1810Lane departure alert function is operating.
Operation display of steering
wheel operation support
Indicates that steering
wheel assistance of
the steering control function is operating.
Lane departure alert function dis-
play
Displayed when the mu lti-information dis-
play is switched to the driving assist system
information screen.
Inside of displayed white lines is
white
Indicates that the system is recognizing
white (yellow) lines. When the vehicle
departs from its lane , the white line dis-
played on the side the vehicle departs from
flashes orange.
Inside of displayed white lines is
black
Indicates that the system is not able to rec-
ognize white (yellow) lines or is temporar-
ily canceled.
■Operation conditions of each function
●Lane departure alert function
This function operates when all of the fol-
lowing conditions are met.
• LDA is turned on.
• Vehicle speed is ap proximately 32 mph
(50 km/h) or more.
• System recognizes white (yellow) lines.
• Width of traffic lane is approximately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated.
• Vehicle is driven on a straight road or around a gentle curve with a radius of
more than approximately 492 ft. (150 m).
• No system malfunctions are detected.
( P.166)
●Steering control function
This function operates when all of the fol-
lowing conditions are met in addition to the
operation conditions for the lane depar-
ture alert function.
• Setting for “Steering Assist” in of the multi-information display is set to “On”.
( P.71)
• Vehicle is not acceler ated or decelerated
by a certain 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.165)
●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.71)
• Vehicle speed is ap proximately 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.166)
■Temporary cancellation of functions
When the operation conditions are no lon-
ger met, a function may be temporarily can-
B
C

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celed. However, wh en the operation
conditions are met again, operation of the
function is automatically restored. ( P.164)
■Steering control function
Depending on the vehicle speed, lane
departure situation, ro ad conditions, etc.,
the driver may not feel the function is oper-
ating or the function may not operate at all.
■Lane departure alert function
The warning buzzer may be difficult to hear
due to external noise, audio playback, etc.
Also, it may be difficult to feel steering
wheel vibrations due to the road conditions
etc.
■Hands off steering wheel warning
When the system determines that the driver
has removed their hands from the steering
wheel while the steering control function is
operating, a warning message urging the
driver to hold the steering wheel and the
symbol shown in the illustration are dis-
played on the multi-information display.
If the driver continue s to keep their hands
off of the steering wheel, a warning mes-
sage and the symbol shown in the illustra-
tion are displayed on the multi-information
display, and the function is temporarily can-
celed. This warning also operates in the
same way when the driver continuously
operates the steering wheel only a small
amount. Always keep your hands on the
steering wheel when using this system,
regardless of warnings.
Depending on the vehicle and road condi-
tions, the warning may not operate.
■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 displayed on the
multi-information display.
Depending on the vehicle and road condi-
tions, the warning may not operate.
■White (yellow) lines are only on one side
of road
The LDA system will not operate for the
side on which white (yellow) lines could not
be recognized.
■Conditions in whic h functions may not
operate properly
In the following situations, the camera sen-
sor may not detect white (yellow) lines and
various functions may not operate normally.
●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 intersec-
tion, 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 reco gnize than lines that
are white).
●The white (yellow) lines cross over a curb,
etc.
●The vehicle is driven on a bright surface,
such as concrete.
●The vehicle is driven on a surface that is
bright due to reflected light, etc.
●The vehicle is driven in an area where the

1664-5. Using the driving support systems
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0_OM_(U)_1810brightness changes suddenly, such as at
the entrances and exits of tunnels, etc.
●Light from the headlights of an oncoming
vehicle, the sun, etc. enters the camera.
●The vehicle is driven where the road
diverges, merges, etc.
●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 vehicle is driven around a sharp
curve.
●The traffic lane is ex
cessively narrow or
wide.
●The vehicle is extremely tilted due to car-
rying 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).
●The headlight lenses are dirty and emit a
faint amount of light at night, or the beam
axis has deviated.
●The vehicle is struck by a crosswind.
●The vehicle has just changed lanes or
crossed an intersection.
●Snow tires, etc. are equipped.
■Warning message
If the following warning messag e is displayed on the multi-information display and the LDA
indicator illuminates in orange, follow th e appropriate troubleshooting procedure.
Warning messageDetails/Actions
“Lane Departure Alert Malfunction
Visit Your Dealer”The system may not be operating properly.
Have the vehicle inspected at your Lexus dealer.
“Front Camera Unavailable Remove
Debris On Windshield”
Dirt, rain, condensation, ice, snow, etc. are present
on the windshield in front of the camera sensor.
Turn the LDA system off, remove any dirt, rain,
condensation, ice, snow, et c. from the windshield,
and then turn the LDA system back on.
“Front Camera Unavailable”
The operation conditions of the camera sensor
(temperature, etc.) are not met.
 When the operation conditions of the camera
sensor (temperature, etc.) are met, the LDA system
will become available. Turn the LDA system off, wait
for a little while, and then turn the LDA system back
on.
“Lane Departure Alert Unavailable”
The LDA system is temporarily canceled due to a
malfunction in a sensor other than the camera sen-
sor.
 Turn the LDA system off and follow the appropri-
ate troubleshooting procedures for the warning
message. Afterward, drive the vehicle for a short
time, and then turn the LDA system back on.

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If a different warning message is displayed, fo llow the instructions displayed on the screen.
■Customization
The following settings can be changed.
For how to change settings, refer to P.339
“Lane Departure Alert Unavailable
Below Approx 32MPH”
The LDA system cannot be used as the vehicle
speed is less than approx imately 32 mph (50 km/h).
 Drive the vehicle at approximately 32 mph (50
km/h) or more.
“Lane Departure Alert Unavailable
at Current Speed”The LDA system cannot be used as the vehicle
speed is too high.
 Slow down.
Warning messageDetails/Actions
FunctionSetting details
Lane departure
alert functionAdjust alert sensitivity
Adjust alert type
Steering control
functionTurn steering wheel
assistance on and off
Vehicle sway
warning functionTurn function on and
off
Adjust alert sensitivity

1684-5. Using the driving support systems
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Vehicle-to-vehicle distance switch
Display
Set speed
IndicatorsCruise control switch
Dynamic radar cruise con-
trol
In vehicle-to-vehicle distance con-
trol mode, the vehicle automati-
cally accelerates and decelerates
to match the speed changes of the
preceding vehicle even if the accel-
erator pedal is not depressed. In
constant speed control mode, the
vehicle runs at a fixed speed.
Use the dynamic radar cruise con-
trol on freeways and highways.

Vehicle-to-vehicle distance con-
trol mode ( P.170)
 Constant speed control mode
( P.173)
System Components
A
B
C
D
WARNING
■Before using dynamic radar cruise
control
●Driving safely is the sole responsibility
of the driver. Do not rely solely on the
system, and drive safely by always pay-
ing careful attention to your surround-
ings.
●The dynamic radar cruise control pro-
vides driving assistance to reduce the
driver’s burden. However, there are
limitations to the assistance provided.
Read the following conditions care-
fully. Do not overly rely on this system
and always drive carefully.
• When the sensor ma y not be correctly
detecting the vehicle ahead: P.175
• Conditions under which the vehi- cle-to-vehicle distance control mode
may not function correctly: P.175
●Set the speed appropriately depend-
ing on the speed limit, traffic flow, road
conditions, weather conditions, etc.
The driver is responsible for checking
the set speed.
●Even when the system is functioning
normally, the condition of the preced-
ing vehicle as detected by the system
may differ from the condition
observed by the driver. Therefore, the
driver must always remain alert, assess
the danger of each situation and drive
safely. Relying on this system or assum-
ing the system ensures safety while
driving can lead to an accident, result-
ing in death or serious injury.
●Switch the dynamic radar cruise con-
trol off using the “ON/OFF” button
when not in use.
E

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WARNING
■Cautions regarding the driving assist
systems
Observe the following precautions, as
there are limitations to the assistance
provided by the system.
Failure to do so may cause an accident
resulting in death or serious injury.
●Assisting the driver to measure follow-
ing distance
The dynamic radar cruise control is only
intended to help the driver in determin-
ing the following distance between the
driver’s own vehicle and a designated
vehicle traveling ahead. It is not a mecha-
nism that allows careless or inattentive
driving, and it is not a system that can
assist the driver in low-visibility condi-
tions. It is still necessary for driver to pay
close attention to the vehicle’s surround-
ings.
●Assisting the driver to judge proper
following distance
The dynamic radar cruise control deter-
mines whether the following distance
between the driver’s own vehicle and a
designated vehicle traveling ahead is
within a set range. It is not capable of
making any other type of judgement.
Therefore, it is abso lutely necessary for
the driver to remain vigilant and to deter-
mine whether or not there is a possibility
of danger in any given situation.
●Assisting the driver to operate the
vehicle
The dynamic radar cruise control has
limited capability to prevent or avoid a
collision with a vehicle traveling ahead.
Therefore, if there is ever any danger, the
driver must take immediate and direct
control of the vehicle and act appropri-
ately in order to ensure the safety of all
involved.
■Situations unsuitable for dynamic
radar cruise control
Do not use dynamic radar cruise control
in any of the following situations.
Doing so may result in inappropriate
speed control and could cause an acci-
dent resulting in death or serious injury.
●Roads where there are pedestrians,
cyclists, etc.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those cov-
ered with rain, ice or snow
●On steep downhills, or where there
are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set
speed when driving down a steep hill.
●At entrances to freeways and highways
●When weather conditions are bad
enough that they may prevent the sen-
sors from detectin g correctly (fog,
snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the
front surface of th e radar sensor or
camera sensor
●In traffic conditions that require fre-
quent repeated acceleration and
deceleration
●During emergency towing
●When an approach warning buzzer is
heard often

1704-5. Using the driving support systems
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This mode employs a radar sensor to detect the presence of vehicles up to approx-
imately 328 ft. (100 m) ahead, determines the current vehicle-to-vehicle following
distance, and operates to maintain a suit able following distance from the vehicle
ahead.
Note that vehicle-to-vehicle distance will close in when traveling on downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle distance
can also be set by operating the vehicle-to-vehicle distance switch.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When a vehicle is detected running ahead of you, the system automatically decelerates
your vehicle. When a greater reduction in vehicle speed is necessary, the system applies
the brakes (the stop lights will come on at this time). The sy stem will respond to changes in
the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle distance set by
the driver. Approach warning warns you when th e system cannot decelerate sufficiently to
prevent your vehicle from closing in on the vehicle ahead.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed
The system accelerates until the set speed is re ached. The system then returns to constant
speed cruising.
Driving in vehicle-to-vehicle distance control mode
A
B
C