2021 LEXUS RC300 warning

1734-5. Using the driving support systems
4
Driving
celed. However, when the operation
conditions are met again, operation of the
function is automatically restored. ( P.172)
■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
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 warnings.
●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 func-
tion is temporarily ca nceled. This warning
also operates 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 .
Depending on the vehicle condition and
road conditions, the warning may not operate. Also, if the sy
stem determines that
the vehicle is driving around a curve, warn-
ings 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 operating, 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 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.

1744-5. Using the driving support systems
●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, such 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 recognize 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
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.

1754-5. Using the driving support systems
4
Driving
If a different warning message is displayed, follow the instructions displayed on the screen.
■Customization
The following settings can be changed.
For how to change settings, refer to P.351
“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.
“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

1764-5. Using the driving support systems
Vehicle-to-vehicle distance switch
Display
Set speed
IndicatorsCruise control switch
Dynamic radar cruise con-
trol with full-speed range
In vehicle-to-vehicle distance con-
trol mode, the vehicle automati-
cally accelerates, decelerates and
stops to match the speed changes
of the preceding vehicle even if the
accelerator pedal is not depressed.
In constant speed control mode,
the vehicle runs at a fixed speed.
Use the dynamic radar cruise con-
trol with full-speed range on free-
ways and highways.

Vehicle-to-vehicle distance con-
trol mode ( P.178)
 Constant speed control mode
( P.182)
System Components
A
B
C
D
WARNING
■Before using dynamic radar cruise
control with full-speed range
●Driving safely is th e 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 with
full-speed range provides driving
assistance to reduce the driver’s bur-
den. 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.184
• Conditions under which the vehi- cle-to-vehicle distance control mode
may not function correctly:
P.184
●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 with full-speed range off using the
“ON/OFF” button when not in use.
E

1774-5. Using the driving support systems
4
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 with
full-speed range is only intended to help
the driver in determining the following
distance between the driver’s own vehi-
cle and a designated vehicle traveling
ahead. It is not a me chanism that allows
careless or inattentive driving, and it is
not a system that can assist the driver in
low-visibility conditio ns. It is still neces-
sary for driver to pay close attention to
the vehicle’s surroundings.
●Assisting the driver to judge proper
following distance
The dynamic radar cruise control with
full-speed range determines whether the
following distance be tween 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 absolutely
necessary for the driver to remain vigi-
lant and to determine 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 with
full-speed range 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 vehi-
cle and act appropriately in order to
ensure the safety of all involved.
■Situations unsuitable for dynamic
radar cruise control with full-speed
range
Do not use dynamic radar cruise control
with full-speed range in any of the follow-
ing 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

1784-5. 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 system 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.
When the vehicle ahead of you stops, your vehi cle will also stop (vehicle is stopped by sys-
tem control). After the vehicle ahead starts off, pushing the cruise control lever up or
depressing the accelerator pedal will resume follow-up cruising.
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

1814-5. Using the driving support systems
4
Driving
After the vehicle ahead of you starts
off, push the lever up.
Your vehicle will also resume follow-up
cruising if the accelerator pedal is
depressed after the vehicle ahead of
you starts off.1
Pulling the lever toward you can-
cels the speed control.The speed control is also canceled when
the brake pedal is depressed. (When the
vehicle has been stopped by system con-
trol, depressing the brake pedal does not
cancel the setting.)
2Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, when a vehicle ahead is not
detected, 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.
MediumApproximately 130 ft. (40
m)
ShortApproximately 100 ft. (30
m)
Resuming follow-up cruising
when the vehicle has been
stopped by system control (vehi-
cle-to-vehicle distance control
mode)
Distance optionsVehicle-to-vehicle dis- tanceCanceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)

1824-5. Using the driving support systems
■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 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.
2
Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 30 mph [50 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 beco mes the set speed.
Adjusting the speed setting: P.179
Canceling and resuming the speed setting:
 P.181
■Dynamic radar cruise control with
full-speed range 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-
Selecting constant speed con-
trol mode