2019 LEXUS RCF warning

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)

2514-5. Using the driving support systems
4
Driving
RC F_U ◆ Pre-collision warning
When the system determines that
the possibility of a frontal collision is
high, a buzzer will sound and a warn-
ing message will be displayed on the
multi-information display to urge the
driver to take evasive action.
◆ Pre-collision brake assist
When the system determines that the po ssibility of a frontal collision is high,
the system applies greater braking force in relation to how strongly the brake
pedal is depressed.
◆ Pre-collision braking
When the system determines that the po ssibility of a frontal collision is high,
the system warns the driver. If the syst em determines that the possibility of a
frontal collision is extremely high, the br akes are automatically applied to help
avoid the collision or reduce the collision speed.
◆ Suspension control (if equipped)
When the system determines that the po ssibility of a frontal collision is high,
the Adaptive Variable Suspension System (  P. 313) will control the damping
force of the shock absorbers to help ma intain an appropriate vehicle posture.
◆ Steering control (if equipped)
When the system determines that the possibility of a frontal collision is high
and the driver is operating the steering wheel, the LDH system (  P. 313) will
control the turning angle of the front an d rear wheels and effort necessary to
turn the steering wheel to help enhance steering responsiveness.

252 4-5. Using the driving support systems
RC F_U WARNING ■
Limitations of the pre-collision system●
The driver is solely responsible for safe driving. Always drive safely, taking care to
observe your surroundings.
Do not use the pre-collision sy stem instead of normal braking operations under any
circumstances. This system will not preven t collisions or lessen collision damage or
injury in every situation. Do not overly rely on this system. Failure to do so may lead to
an accident, resulting in death or serious injury. ●
Although this system is designed to help avoid a collision or help reduce the impact of
the collision, its effectivenes s may change according to various conditions, therefore
the system may not always be able to achieve the same level of performance.
Read the following conditions carefully. Do not overly rely on this system and always
drive carefully.
• Conditions under which the system may oper ate even if there is no possibility of a
collision:  P. 256
• Conditions under which the system may not operate properly:  P. 258●
Do not attempt to test the operation of the pre-collision system yourself, as the system
may not operate properly, possib ly leading to an accident.■
Pre-collision braking ●
When the pre-collision braking function is operating, a large amount of braking force
will be applied. ●
If the vehicle is stopped by the operation of the pre-collision braking function, the pre-
collision braking function operation will be canceled after approximately 2 seconds.
Depress the brake pedal as necessary. ●
The pre-collision braking fu nction may not operate if certain operations are per-
formed by the driver. If the accelerator pedal is being depressed strongly or the steer-
ing wheel is being turned, the system may de termine that the driver is taking evasive
action and possibly prevent the pre-coll ision braking function from operating.●
In some situations, wh ile the pre-collision braking function is operating, operation of
the function may be canceled if the accele rator pedal is depressed strongly or the
steering wheel is turned and the system de termines that the driv er is taking evasive
action. ●
If the brake pedal is being depressed, the sy stem may determine that the driver is tak-
ing evasive action and possibly delay the op eration timing of the pre-collision braking
function.

2534-5. Using the driving support systems
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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

254 4-5. Using the driving support systems
RC F_U ■
Enabling/disabling the pre-collision system
The pre-collision system can be enabled/disabled on (  P. 111) of the
multi-information display. The system is automatically enabled each time the engine switch is turned to IGNI-
TION ON mode.
If the system is disabled, the PCS
warning light will turn on and a mes-
sage will be displayed on the multi-
information display. ■
Changing the pre-collision warning timing
The pre-collision warning timing can be changed on (  P. 111) of the
multi-information display. The operation timing setting is retained when the engi ne switch is turned off.
Far The warning will begin to operate
earlier than with the default timing.
Middle This is the default setting.
Near The warning will begin to operate
later than with the default timing.Changing settings of the pre-collision system
1
2
3

2554-5. Using the driving support systems
4
Driving
RC F_U ■
Operational conditions
The pre-collision system is enabled and the sy stem determines that the possibility of a
frontal collision with a vehicle or pedestrian is high.
Each function is operationa l at the following speeds:●
Pre-collision warning:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 7 mph (10 km/h) or more. ●
Pre-collision brake assist:
• Vehicle speed is between approximately 20 and 110 mph (30 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 20 and 50 mph
[30 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 20 mph (30 km/h) or more. ●
Pre-collision braking:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 7 mph (10 km/h) or more.
The system may not operate in the following situations: ●
If a battery terminal has been disconnected and reconnected and then the vehicle has
not been driven for a certain amount of time ●
If the shift lever is in R ●
If VSC is disabled (only the pre-collis ion warning function will be operational)■
Pedestrian detection function
■
Cancelation of the pre-collision braking
If either of the following occur while the pre-co llision braking function is operating, it will
be canceled: ●
The accelerator pedal is depressed strongly. ●
The steering wheel is turned sharply or abruptly.The pre-collision system detects pedestrians
based on the size, prof ile, and motion of a
detected object. However, a pedestrian may not
be detected depending on the surrounding
brightness and the motion, posture, and angle of
the detected object, preventing the system from
operating properly. (  P. 259)

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.

2614-5. Using the driving support systems
4
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