2020 LEXUS RC300 sensor

1634-5. Using the driving support systems
4
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

1684-5. Using the driving support systems
brightness 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 excessively 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.

1704-5. Using the driving support systems
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.172)
 Constant speed control mode
( P.175)
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.177
• Conditions under which the vehi- cle-to-vehicle distance control mode
may not function correctly:
P.177
●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

1714-5. Using the driving support systems
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Driving
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

1724-5. Using the driving support systems
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

1754-5. Using the driving support systems
4
Driving
1Pulling 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 dynamic radar cruise control
Canceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)
Selecting constant speed con-
trol mode

1764-5. Using the driving support systems
indicator will come on. Afterwards, it
switches to the cruise control indicator.
Switching to constant speed control mode
is only possible when operating the lever
with the cruise control off.
2Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 25 mph [40 km/h])
and push the lever down to set the
speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the lever
is released becomes the set speed.
Adjusting the sp eed setting: P.173
Canceling and resuming the speed setting:
 P.175
■Dynamic radar cruise control can be set
when
●The shift lever is in D.
●Range 4 or higher of D has been selected
by using the paddle shift switch.
●Vehicle speed is at or above approxi- mately 30 mph (50 km/h).
■Accelerating after setting the vehicle
speed
The vehicle can accelerate by operating the
accelerator pedal. After accelerating, the
set speed resumes. Ho wever, during vehi-
cle-to-vehicle distance control mode, the
vehicle speed may decrease below the set
speed in order to main tain the distance to
the preceding vehicle.
■Automatic cancelation of vehi-
cle-to-vehicle dist ance control mode
Vehicle-to-vehicle distance control mode is
automatically canceled in the following situ-
ations:
●Actual vehicle speed falls at or below
approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●When snow mode is set.
●The sensor cannot detect correctly
because it is covered in some way.
●Pre-collision braking is activated.
If vehicle-to-vehicle distance control mode
is automatically canceled for any other
reason, there may be a malfunction in the
system. Contact your Lexus dealer.
■Automatic cancelation of constant
speed control mode
Constant speed control mode is automati-
cally canceled in the following situations:
●Actual vehicle speed is more than
approximately 10 mph (16 km/h) below
the set vehicle speed.
●Actual vehicle speed falls below approxi-
mately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●Pre-collision braking is activated.
If constant speed control mode is automati-
cally canceled for any other reason, there

1774-5. Using the driving support systems
4
Driving
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.175) 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