2020 LEXUS RC300 Lane Departure Alert

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

1664-5. Using the driving support systems
Lane 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.168)
●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.69)
• 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.167)
●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.69)
• 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.168)
■Temporary cancellation of functions
When the operation conditions are no lon-
ger met, a function may be temporarily can-
B
C

1674-5. Using the driving support systems
4
Driving
celed. However, when the operation
conditions are met again, operation of the
function is automatically restored. ( P.166)
■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

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.

1694-5. 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.341
“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

1984-6. Driving tips
4-6.Driving tips
Use fluids that are appropriate to
the prevailing outside temperatures.
• Engine oil
• Engine coolant
• Washer fluid
Have a service technician inspect
the condition of the battery.
 Have the vehicle fitted with four
snow tires or purchase a set of tire
chains for the rear tires.
*
Ensure that all tires are the specified size
and brand, and that chains match the size
of the tires.
*: Tire chains cannot be mounted on vehi-
cles with front and rear tires of differing
sizes and vehicles with LDH and 19-inch
tires.
Perform the following according to the
driving conditions:
 Do not try to forcibly open a window
or move a wiper that is frozen. Pour
Winter driving tips
Carry out the necessary prepara-
tions and inspections before driving
the vehicle in winter. Always drive
the vehicle in a manner appropriate
to the prevailing weather condi-
tions.
Preparation for winter
WARNING
■Driving with snow tires
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in a loss of
vehicle control and cause death or seri-
ous injury.
●Use tires of the specified size.
●Maintain the recommended level of air
pressure.
●Do not drive in excess of 75 mph (120
km/h), regardless of the type of snow
tires being used.
●Use snow tires on all, not just some
wheels.
■Driving with tire chains
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in the vehicle
being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed
limit specified for the tire chains being
used, or 30 mph (50 km/h), which-
ever is lower.
●Avoid driving on bumpy road surfaces
or over potholes.
●Avoid sudden acceleration, abrupt
steering, sudden br aking and shifting
operations that cause sudden engine
braking.
●Slow down sufficiently before entering
a curve to ensure that vehicle control is
maintained.
●Do not use LDA (Lane Departure
Alert with steering control) system.
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow
tires from Lexus dealers or legitimate tire
retailers.
This is because the removal and attach-
ment of snow tires affects the operation
of the tire pressure warning valves and
transmitters.
Before driving the vehicle

2877-2. Steps to take in an emergency
7
When trouble arises
■LDA (Lane Departure Alert) indicator
■PCS warning light
■Slip indicator
Warning lightDetails/Actions
(orange)
If the LDA indicator is illuminated:
Indicates a malfunction in the LDA (Lane Departure Alert with steering
control) system.
Check the warning message displayed on the multi-information
display. ( P.168)
If the LDA indicator flashes:
Indicates that the vehicle has deviated from the lane (while the LDA
[Lane Departure Alert with steering control] system is operating)
 Check the area around the vehicle and return the vehicle to
between the lane lines.
Warning lightDetails/Actions
(flashes or illumi-
nates)
When a buzzer sounds simultaneously:
Indicates a malfunction has occurred in the PCS (Pre-Collision System).
 Have the vehicle inspected by your Lexus dealer immediately.
When a buzzer does not sound:
The PCS (Pre-Collision System) has become temporarily unavailable,
corrective action may be necessary.
 Follow the instructions displayed on the multi-information display.
(  P.154, 294)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability Control)
system is disabled, the PCS warning light will illuminate.
 P.162
Warning lightDetails/Actions
Indicates a malfunction in:
The VSC (Vehicle Stability Control) system;
 The TRAC (Traction Control) system; or
 The hill-start assist control system
The light will flash when the VSC or the TRAC system is operating.
 Have the vehicle inspected by your Lexus dealer immediately.

2947-2. Steps to take in an emergency
In some situations, the master warning light and warning buzzer may not oper-
ate as specified. In this case, follow the instructions displayed in the warning
message.
 If a warning light comes on or flashes at the same time that a warning message is
displayed, take corrective actio n according to the warning light. ( P.284)
*: A buzzer sounds the first time a message is shown on the multi-information display.
■Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications.
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level is low. Check the level
of the engine oil, and add if necessary.
This message may appear if the vehicle is
stopped on a slope. Move the vehicle to a
level surface and check to see if the mes-
sage disappears.
■If “Front Camera Unavailable” or “Front
Camera Unavailable Remove Debris
On Windshield” is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.154, 287)
●PCS (Pre-Collision System)
●LDA (Lane Departure Alert with steering
control)
●Automatic High Beam
●Dynamic radar cruise control
■If “Maintenance Required Soon” is dis-
played
Indicates that all maintenance according to
the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( P.240)
*: Refer to the separate “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the main tenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all mainte nance is required to
correspond to the driven distance on the
maintenance schedule
*.
Comes on approximately 5000 miles
(8000 km) after the message has been
reset. (The indicator will not work properly
unless the message ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( P.240)
*: Refer to the separate “Scheduled Main-
Comes onDoes not sound
Indicates a condition, such as malfunction of electri-
cal components, their cond ition, or indicates the
need for maintenance
FlashesDoes not sound
Indicates a situation, such as when an operation has
been performed incorrectly, or indicates how to
perform an operation correctly
Warning buzzer*Warning