2614-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
■Sensor detection information
●RC350: The sensor’s detection areas are limited to the areas around the vehicle’s front
and rear bumpers.
●RC F: The sensor’s detection areas are limited to the areas around the vehicle’s front
corner and rear bumpers.
●Certain vehicle conditions and the surround ing environment may affect the ability of
the sensor to correctly detect obstacles. Particular instances where this may occur are
listed below.
• There is dirt, snow or ice on the sensor . (Wiping the sensors will resolve this prob-
lem.)
• The sensor is frozen. (Thawing th e area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen may show an abnormal
display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning co nsiderably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines, air brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensor in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under the bumpers is not detected.
• If obstacles draw too close to the sensor.
• A non-genuine Lexus suspension (low ered suspension etc.) is installed.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there are instances in which, because of their shape,
signs and other objects may be judged by the sensor to be closer than they are.
●The shape of the obstacle may prevent the sensor from detecting it. Pay particular
attention to the following obstacles:
• Wires, fences, ropes, etc.
• Cotton, snow and other materials that absorb sound waves
• Sharply-angled objects
•Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your vehi-
cle
●The following situations may occur during use.
• Depending on the shape of the obstacle and other factors, the detection distance
may shorten, or detect ion may be impossible.
• Obstacles may not be detected if they are too close to the sensor.
• There will be a short delay between obst acle detection and display. Even at slow
speeds, there is a possibility that the obstacle will come within the sensor’s detection
areas before the display is shown and the warning beep sounds.
• Thin posts or objects lower than the sensor may not be detected when approached, even if they have been detected once.
• It might be difficult to hear beeps due to the volume of the audio system or air flow noise of the air conditioning system.
2824-5. Using the driving support systems
RC350/RCF_U (OM24636U)
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if the
brakes are applied while drivin g on a slippery road surface
◆Brake assist
Generates an increased level of braking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning on
slippery road surfaces
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Prevents the vehicle from rolling backward when starting on an incline or slip-
pery slope
◆VGRS (Variable Gear Ratio Steering) (if equipped)
Adjusts the front wheel turning angle in accordance with the vehicle speed
and steering wheel movement
◆DRS (Dynamic Rear Steering) (if equipped)
Contributes to the turning characteristics and responsiveness of the vehicle
by slightly adjusting the rear wheel angle of the vehicle in accordance with
steering wheel movement.
Driving assist systems
To help enhance driving safety and performance, the following systems oper-
ate automatically in response to various driving situations. Be aware, however,
that these systems are supplementary and should not be relied upon too
heavily when operating the vehicle.
2834-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
◆Adaptive Variable Suspension system (if equipped)
By independently controlling the dampin g force of the shock absorbers for
each of the 4 wheels according to the road and driving conditions, this system
combines riding comfort with superior steering stability, and helps good vehi-
cle posture. ( P. 2 7 9 )
◆LDH (Lexus Dynamic Handling system) (if equipped)
Provides integrated control of the VGRS, DRS and EPS. Contributes to turn-
ing characteristics at low speeds, re sponsiveness at medium speeds and
safety at high speeds by controlling the steering angle of the front and rear
wheels in accordance with the steering wheel operation and vehicle speed.
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, EPS, VGRS (if equi pped) and DRS (if equipped) systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, steering assist, and if equipped with
VGRS, steering ratio
◆PCS (Pre-Collision System) (if equipped)
P. 2 9 0
◆BSM (Blind Spot Monitor) (if equipped)
P. 2 9 7
◆TVD (Torque Vectoring Differential) (if equipped)
P. 3 1 3
2884-5. Using the driving support systems
RC350/RCF_U (OM24636U)
WA R N I N G
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operat ing may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable while drivin g on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill- start assist control does not operate effectively when
●Do not overly rely on hill-start assist contro l. Hill-start assist control may not operate
effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist control is not intended to hold the vehicle
stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.
■When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes.
2904-5. Using the driving support systems
RC350/RCF_U (OM24636U)
◆ Pre-collision warning
When a high possibility of a frontal
collision is detected, the pre-colli-
sion system warning light flashes, a
buzzer sounds and a message is
shown on the multi-information dis-
play to urge the driver to take eva-
sive action.
◆Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to ho w strongly the brake pedal is depressed.
The system may not warn the driver using a warning light, warning display and
buzzer when the system detects and judges braking operations.
◆Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warning di splay and buzzer. If the system deter-
mines that a collision is unavoidable, the brakes are automatically applied to
reduce the collision speed.
◆Suspension control (if equipped)
When the system determines that there is a high possibility of a frontal colli-
sion, the operation of Adaptive Variable Suspension System ( P. 2 8 3 ) o p t i -
mally controls the damping force of the shock absorber.
PCS (Pre-Collision System)
: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes are
automatically engaged to lessen im pact as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by operating
the switch. ( P. 2 9 1 )
2914-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
◆Steering control (if equipped)
When the system determines that there is a high possibility of a frontal colli-
sion while the steering wheel is being operated, the LDH (Lexus Dynamic
Handling) system controls the steering angle of the front and rear wheels and
torque applied to the steering wheel to enhance the steering wheel operation
response.
Enabled
Disabled
The pre-collision system warning light
comes on when pre-collision system is
disabled.
The radar sensor detects vehicles or
other obstacles on or near the road
ahead and determines whether a colli-
sion is imminent based on the position,
speed, and heading of the obstacles.
Disabling pre-collision system
1
2
Radar sensor
2934-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
■Conditions that may trigger the system even if there is no danger of a collision
In the following situations, the front of the sensor may be obstructed causing the system
to determine that there is a poss ibility of a collision and operate:
●When passing an oncoming vehicle on a cu rb or while making a left or right turn
●When rapidly closing on an obstruction in front of the vehicle, such as a vehicle or toll
gate
●When climbing a hill, and an overhead structure (billboard, low ceiling, street lamps,
etc.) appears in the vehicle’s line of travel
●When driving through a narrow passage or a place with a low ceiling (bridges, tunnels,
overhead passes, etc.)
●When driving on an uneven road surface
●When there is a metal object on the road surf ace, or a gap or protrusion in the road sur-
face
●When there is an extreme change in the vehicle height
●When the sensor is misaligned due to a stro ng impact to the surrounding area of the
sensor
●When there is an object on the side of the road at the entrance to a curve, such as
guardrails
●When the front of your vehicle is inclined (during emergency towing, carrying a heavy
load in the trunk, etc.)
When the system is activated in the situations described above, there is also a possibility
that the brakes will be applied with a force greater than normal.
■Obstacles not detected
The sensor cannot detect plasti c obstacles such as traffic cones. There may also be occa-
sions when the sensor cannot detect pedestrians, animals, bicycles, motorcycles, trees,
or snowdrifts.
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●If the vehicle is skidding when VSC is not operating
●When your vehicle is steeply inclined
●When the radar sensor moves off position due to its surrounding area being subjected
to a strong impact
●When an obstacle suddenly appears in front of the vehicle due to the steering wheel
being turned sharply or another cause
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor cont amination, etc. that results in the sensors
being unable to detect obstacles, the pre-collision syst em will be automatically disabled.
In this case, the system will not activate even if there is a collision possibility.
■When there is a malfunction in the system or if the system is temporarily unusable
The pre-collision system warning light will flash or illuminate and warning messages will
be displayed. ( P. 5 3 4 , 5 4 5 )
2964-5. Using the driving support systems
RC350/RCF_U (OM24636U)
WA R N I N G
■Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre- collision system is intended to assist the
driver in avoiding collisions through the process of LOOK-JUDGE-ACT. There are
limits to the degree of assistance the system can provide, so please keep in mind the
following important points.
●Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the vehicle,
and only within a limited range. It is not a mechanism that allows careless or inatten-
tive driving, and it is not a system that can assist the driver in low-visibility conditions. It
is still necessary for the driver to pay cl ose attention to the vehicle’s surroundings.
●Assisting the driver in making correct judgment
When attempting to estimate the possibility of a collision, the only data available to
the pre-collision system is that from obstacle s it has detected directly in front of the
vehicle. Therefore, it is absolutely necess ary for the driver to remain vigilant and to
determine whether or not there is a possib ility of collision in any given situation.
●Assisting the driver in taking action
The pre-collision brake assist function of th e pre-collision safety system is designed to
help reduce the severity of a collision, an d will only operate when the system deter-
mines that a collision is unavoidable. Withou t proper input from the driver, this system
is not capable of avoiding a collision or brin ging the vehicle to a stop safely. For this
reason, when encountering a dangerous situation the driver must take direct and
immediate action in order to ensu re the safety of all involved.