sensor LEXUS RCF 2019 Owner's Manual

250 4-5. Using the driving support systems
RC F_UPCS (Pre-Collision System) The pre-collision system uses a radar sensor and camera sensor to detect
vehicles and pedestrians in front of yo ur vehicle. When the system determines
that the possibility of a frontal collision with a vehicle or pedestrian is high, a
warning operates to urge the driver to take evasive action and the potential
brake pressure is increased to help the driver avoid the collision. If the system
determines that the possibility of a fr ontal collision with a vehicle or pedes-
trian is extremely high, the brakes are automatically applied to help avoid the
collision or help reduce the impact of the collision.
The pre-collision system can be disabled/enabled and the warning timing can
be changed. (  P. 254)

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Driving
RC F_U WARNING ■
When to disable the pre-collision system
In the following situations, di sable the system, as it may not operate properly, possibly
leading to an accident resultin g in death or serious injury:●
When the vehicle is being towed ●
When your vehicle is towing another vehicle ●
When transporting the vehicle via truck, bo at, train or similar means of transportation●
When the vehicle is raised on a lift with the engine running and the tires are allowed to
rotate freely ●
When inspecting the vehicle using a drum tester such as a chassis dynamometer or
speedometer tester, or when using an on vehicle wheel balancer ●
When a strong impact is applied to the fron t bumper or front grille, due to an accident
or other reasons ●
If the vehicle cannot be driven in a stable manner, such as when the vehicle has been
in an accident or is malfunctioning ●
When the vehicle is driven in a sporty manner or off-road●
When the tires are not properly inflated ●
When the tires are very worn ●
When tires of a size other than specified are installed ●
When tire chains are installed ●
When a compact spare tire or an emergency tire puncture repair kit is used ●
If equipment (snow plow, etc.) that may obstruct the radar sensor or camera sensor is
temporarily installed to the vehicle

258 4-5. Using the driving support systems
RC F_U ■
Situations in which the system may not operate properly ●
In some situations such as the following, a vehicle may not be detected by the radar
sensor and camera sensor, preventing the system from operating properly:
• If an oncoming vehicle is approaching your vehicle
• If a vehicle ahead is a motorcycle or bicycle
• When approaching the side or front of a vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shap ed, such as a tractor or side car
• If the sun or other light is shin ing directly on a vehicle ahead
• If a vehicle cuts in front of your ve hicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, accelera-
tion or deceleration)
• When suddenly cutting behind a preceding vehicle
• When driving in inclement we ather such as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, sn ow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes suddenly, such
as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of on coming traffic, shines
directly into the camera sensor
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a
tunnel• If a preceding vehicle has a low rear end,
such as a low bed trailer
• If a vehicle ahead has extremely high
ground clearance
• When a vehicle ahead is not directly in front
of your vehicle

2594-5. Using the driving support systems
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Driving
RC F_U • After the engine has started the vehicle has not been driven for a certain amount of
time
• While making a left/right turn and for a few seconds after making a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the wheels are misaligned
• If a wiper blade is blocking the camera sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or ca mera sensor is misaligned●
In some situations such as the following, sufficient braking forc e may not be obtained,
preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake
parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively worn,
improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery surface●
Some pedestrians such as the following may not be detected by the radar sensor and
camera sensor, preventing the system from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5
ft. (2 m)
• Pedestrians wearing oversized clothing (a ra in coat, long skirt, etc.), making their sil-
houette obscure
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part
of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller , wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as
their surroundings
• Pedestrians near walls, fences , guardrails, or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from be hind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view
mirror, etc.)• If the front of the vehicle is raised or low-
ered

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
RC F_U ■
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

2714-5. Using the driving support systems
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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