2019 LEXUS RCF sensor

260 4-5. Using the driving support systems
RC F_U ■
If the PCS warning light flas hes or illuminates and a warning message is displayed on
the multi-inform ation display
The pre-collision system may be temporarily unavailable or there may be a malfunction
in the system. ●
In the following situations, the warning light will turn off, the message will disappear and
the system will become operational when normal operating conditions return:
• When the radar sensor or ca mera sensor or the area around either sensor is hot,
such as in the sun
• When the radar sensor or camera sensor or the area around either sensor is cold,
such as in an extremely cold environment
• When a front sensor is dirt y or covered with snow, etc.
• When the part of the windshield in front of the camera sensor is fogged up or cov-
ered with condensation or ice (Defogging the windshield:
 P. 338)
• If the camera sensor is obstructed, such as when the hood is open or a sticker is
attached to the windshield near the camera sensor ●
If the PCS warning light continues to flash or remains illuminated or the warning mes-
sage does not disappear even though the vehicle has returned to normal, the system
may be malfunctioning. Have the vehicle in spected by your Lexus dealer immediately.■
If VSC is disabled ●
If VSC is disabled (  P. 315), the pre-collision brake a ssist and pre-collision braking
functions are also disabled. ●
The PCS warning light will turn on and “V SC Turned Off Pre-Collision Brake System
Unavailable” will be displayed on the multi-information display.

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Driving
RC F_U When driving on highways and freeways wi th white (yellow) lines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering whee l 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.
◆ Lane departure alert function
When the system determines that
the vehicle might depart from its
lane, a warning is displayed on the
multi-information 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 surrounding road situation and
carefully operate the steering wheel
to move the vehicle back to the cen-
ter of the lane.LDA (Lane Departure Alert with steering control) Summary of functions
Functions included in LDA system

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Driving
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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 which functions may not operate properly
In the following situations, the camera sensor may not detect white (yellow) lines and var-
ious 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 ar ea without white (yellow) lines, such as in front of a tollgate
or checkpoint, or at an intersection, 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 t ilts 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 carry ing 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 am ount due to road conditions during driv-
ing (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 lane s or crossed an intersection.●
Snow tires, etc. are equipped. ■
Warning message
Warning messages are used to indicate a syst em malfunction or to inform the driver of
the need for caution while driving. (  P. 460)■
Customization
Some functions can be customized (  P. 111)

270 4-5. Using the driving support systems
RC F_U WARNING ■
Situations unsuitable for dy namic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury. ●
Roads where there are pede strians, cyclists, etc.●
In heavy traffic ●
On roads with sharp bends ●
On winding roads ●
On slippery roads, such as thos e covered 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 sensors from
detecting correctly (fog, snow, sandstorm, heavy rain, etc.)●
When there is rain, snow, etc. on the fron t surface of the radar sensor or camera sen-
sor ●
In traffic conditions that require frequent repeated a cceleration and deceleration●
During emergency towing ●
When an approach warning buzzer is heard often

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Driving
RC F_U This mode employs a radar sensor to detect the presence of vehicles up to
approximately 328 ft. (100 m) ahead, de termines the current vehicle-to-vehicle
following distance, and operates to main tain a suitable following distance from
the vehicle ahead. Note that vehicle-to-vehicle distance will cl ose 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 dis-
tance 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 sl ower than the set speed appearsWhen a vehicle is detected running ahead of you, the system automatically deceler-
ates 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). Th e 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 the system cannot
decelerate sufficie ntly 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 reached. The system then returns to con-
stant speed cruising.Driving in vehicle-to-vehicle distance control mode
1
2
3

276 4-5. Using the driving support systems
RC F_U When constant speed control mode is se lected, your vehicle will maintain a set
speed without controlling the vehicle-to-veh icle distance. Select this mode only
when vehicle-to-vehicle distance control mode does not function correctly due
to a dirty radar sensor, etc.
With the cruise control off, press and
hold the “ON/OFF” button for 1.5
seconds or more. Immediately after the “ON/OFF” but-
ton is pressed, the 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.
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 becomes the set speed.
Adjusting the speed setting:  P. 273
Canceling and resuming the speed setting:  P. 274Selecting constant speed control mode 1
2

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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 approximately 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. However, during vehicle-to-vehicle distance control mode, the vehi-
cle speed may decrease below the set speed in order to maintain the distance to the pre-
ceding vehicle. ■
Automatic cancelation of vehicle- to-vehicle distance 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 rea-
son, there may be a malfunction in th e system. Contact your Lexus dealer.

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Automatic cancelation of co nstant speed control mode
Constant speed control mode is automatica lly canceled in the following situations:●
Actual vehicle speed is more than approxim ately 10 mph (16 km/h) below the set vehi-
cle speed. ●
Actual vehicle speed falls 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. ●
Pre-collision braking is activated.
If constant speed control mode is automati cally canceled for any other reason, there may
be a malfunction in the system . Contact your Lexus dealer.■
Warning messages and buzzers fo r dynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or to inform
the driver of the need for ca ution while driving. If a warn ing 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 insuff icient 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. 275) 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 (traile rs 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 detecting of
the sensor