2018 LEXUS RCF warning

262 4-5. Using the driving support systems
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)◆ Steering control function
When the system determines that
the vehicle might depart from its
lane, the system provides assistance
as necessary by operating the steer-
ing 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-
information display and the function
is temporarily canceled.
◆ Vehicle sway warning function
When the vehicle is swaying or
appears as if it may depart from its
lane multiple times, the warning
buzzer sounds and a message is dis-
played on the multi-information dis-
play to alert the driver.

2634-5. Using the driving support systems
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)WARNING ■
Before using LDA system
Do not rely solely upon the LDA system. The LDA system does not automatically drive
the vehicle or reduce the amount of attention that must be paid to the area in front of
the vehicle. The driver must always assume full responsibility for driving safely by pay-
ing careful attention to the surrounding cond itions and operating the steering wheel to
correct the path of the vehicle. Also, the driver must take adequate breaks when
fatigued, such as from driving for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury. ■
To avoid operating LDA system by mistake
When not using the LDA system, use the LDA switch to turn the system off.■
Situations unsuitable for LDA system
Do not use the LDA system in the following situations.
The system may not operate properly and lead to an accident, resulting in death or
serious injury. ●
A spare tire, tire chains, etc. are equipped. ●
When the tires have been excessively worn, or when the tire inflation pressure is low. ●
Tires which differ by structure, manufacturer, brand or tread pattern are used. ●
Objects or patterns that could be mistaken for white (yellow) lines are present on the
side of the road (guardrails, cu rbs, reflective poles, etc.).●
Vehicle is driven on a snow-covered road. ●
White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.●
Asphalt repair marks, white (y ellow) line marks, etc. are present due to road repair.●
Vehicle is driven in a temporary lane or restricted lane due to construction work.●
Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow,
freezing, etc. ●
Vehicle is driven in traffic lanes ot her than on highways and freeways.●
Vehicle is driven in a construction zone. ●
During emergency towing ■
Preventing LDA system malfunctions and operations performed by mistake ●
Do not modify the headlights or place stickers, etc. on the surface of the lights.●
Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact your Lexus dealer. ●
Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.). ●
If your windshield needs repair s, contact your Lexus dealer.

266 4-5. Using the driving support systems
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
Operation conditions of each function ●
Lane departure alert function
This function operates when all of the following conditions are met.
• LDA is turned on.
• Vehicle speed is approximatel y 32 mph (50 km/h) or more.
• System recognizes white (yellow) lines.
• Width of traffic lane is approx imately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated.
• Vehicle is driven on a stra ight road or around a gentle curve with a radius of more
than approximately 492 ft. (150 m).
• No system malfunctions are detected. (  P. 453)●
Steering control function
This function operates when all of the follo wing conditions are met in addition to the
operation conditions for the lane departure alert function.
• Setting for Steering Assist in of th e multi-information display is set to On.
(  P. 111)
• Vehicle is not accelerated or dece lerated by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for changing
lanes.
• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Hands off steering wheel alert is not displayed. (  P. 266)●
Vehicle sway warning function
This function operates when all of the following conditions are met.
• Setting for Sway Warning in of the multi-information display is set to On.
(  P. 111)
• Vehicle speed is approximatel y 32 mph (50 km/h) or more.
• Width of traffic lane is approx imately 9.8 ft. (3 m) or more.
• No system malfunctions are detected. (  P. 453)■
Temporary cancellation of functions
When operation conditions are no longer met, a function may be temporarily canceled.
However, when the operation co nditions are met again, operat ion of the function is auto-
matically restored. (  P. 266)■
Steering control function
Depending on the vehicle speed, lane depart ure situation, road conditions, etc., the
driver may not feel the function is operat ing 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 f eel steering wheel vibrations due to the road conditions, etc.■
Hands off steering wheel alert
When the system determines that the driver has removed the hands from the steering
wheel while the steering control function is operating, a warning message is displayed on
the multi-information display.
If the driver continues to keep the hands of f of the steering wheel, a warning message is
displayed and the function is temporarily canc eled. This alert also operates in the same
way when the driver continuously operates the steering wheel only a small amount.
However, depending on the road conditions, etc., the function may not cancel.

2674-5. Using the driving support systems
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
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)

2694-5. Using the driving support systems
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)WARNING ■
Before using dynamic radar cruise control
Driving safely is the sole responsibility of th e driver. Do not rely solely on the system,
and drive safely by always paying careful attention to your surroundings.
The dynamic radar cruise control provides driving assistance to reduce the driver’s
burden. However, there are limitations to the assistance provided.
Set the speed appropriately depending on the speed limit, traffic flow, road conditions,
weather conditions, etc. The driver is responsible for chec king the set speed.
Even when the system is functioning norma lly, the condition of the preceding vehicle as
detected by the system may differ from the condition observed by the driver. There-
fore, the driver must always remain alert, assess the danger of each situation and drive
safely. Relying on this system or assuming the system ensures safety while driving can
lead to an accident, resultin g in death or serious injury.■
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 following distance
The dynamic radar cruise control is only in tended to help the driver in determining
the following distance between the driver ’s own vehicle and a designated vehicle
traveling ahead. It is not a mechanism that allows careless or ina ttentive driving, and it
is not a system that can assist the driver in low-visibility conditions . It is still necessary
for driver to pay close attention to the vehicle’s surroundings. ●
Assisting the driver to judg e proper following distance
The dynamic radar cruise control determines whether the following distance
between the driver’s own vehicle and a design ated 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 vigilant 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 cont rol 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 vehicle and act appropriately in order to
ensure the safety of all involved.■
To avoid inadvertent dynamic radar cruise control activation
Switch the dynamic radar cruise control o ff using the “ON/OFF” button when not in
use.

270 4-5. Using the driving support systems
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)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
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)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

2754-5. Using the driving support systems
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)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 vehicle-
to-vehicle distance. ■
Warnings may not occur when
In the following instances, warnings ma y not occur even when the vehicle-to-
vehicle distance is small. ●
When the speed of the preceding vehicle matches or exceeds your vehicle
speed ●
When the preceding vehicle is traveling at an extremely slow speed ●
Immediately after the crui se control speed was set●
When depressing the accelerator pedalApproach warning (vehicle-to-vehicle distance control mode)