2019 LEXUS RC300 warning

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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

1734-5. Using the driving support systems
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1 Pulling the lever toward you can-
cels the speed control.
The speed control is also canceled when
the brake pedal is depressed.
2Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, cruise control does not resume
when the vehicle speed is approximately
25 mph (40 km/h) or less.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehi-
cle-to-vehicle distance.
■Warnings may not occur when
In the following instances, warnings
may not occur even when the vehi-
cle-to-vehicle distance is small.
 When the speed of the preceding
vehicle matches or exceeds your
vehicle speed
 When the preceding vehicle is trav-
eling at an extremely slow speed
 Immediately after the cruise control
speed was set
 When depressing the accelerator
pedal
When constant speed control mode is
selected, your vehicle will maintain a
set speed without controlling the vehi-
cle-to-vehicle distance. Select this
mode only when vehicle-to-vehicle dis-
tance control mode does not function
correctly due to a dirty radar sensor,
etc.
1 With the cruise control off, press
and hold the “ON/OFF” button for
1.5 seconds or more.
Immediately after the “ON/OFF” button is
pressed, the radar crui se control indicator
Canceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)
Selecting constant speed con-
trol mode

1754-5. Using the driving support systems
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may be a malfunction in the system. Con-
tact your Lexus dealer.
■Brake system operation sound
If the brakes are applied automatically while
the vehicle is in vehicle-to-vehicle distance
control mode, a brake system operation
sound may be heard. This does not indicate
a malfunction.
■Warning messages and buzzers for
dynamic radar cruise control
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution while driv-
ing. If a warning message is shown on the
multi-information display, read the message
and follow the instructions.
■When the sensor may not be correctly
detecting the vehicle ahead
In the case of the following and depending
on the conditions, operate the brake pedal
when deceleration of the system is insuffi-
cient or operate the accelerator pedal
when acceleration is required.
As the sensor may not be able to correctly
detect these types of vehicles, the approach
warning ( P.173) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same
lane
●Vehicles with small rear ends (trailers
with no load on board, etc.)
●Motorcycles travelin g in the same lane
●When water or snow thrown up by the
surrounding vehicles hinders the detect-
ing of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
■Conditions under which the vehi-
cle-to-vehicle distance control mode
may not function correctly
In the case of the following conditions,
operate the brake pedal (or accelerator
pedal, depending on the situation) as nec-
essary.
As the sensor may not be able to correctly
detect vehicles ahead, the system may not
operate properly.
●When the road curves or when the lanes
are narrow
●When the vehicle ahead of you deceler-
ates suddenly
●When driving on a road surrounded by a
structure, such as in a tunnel or on a
bridge
●When the vehicle speed is decreasing to
the set speed after the vehicle acceler-
ates by depressing the accelerator pedal