Page 289 of 684

2894-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
WA R N I N G
■When the TRAC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As these
are the systems to help ensure vehicle st ability and driving force, do not turn the
TRAC/VSC systems off unless necessary.
■Expert mode precautions
●Do not use on public roads.
●Use only when the road conditions and safety of the surrounding area can be
ensured.
●Proper use of expert mode requires a profes sional level of driving skill. When using
expert mode, always check the road conditions and surrounding area and drive more
carefully than usual.
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension will affect the driving
assist systems, and may caus e a system to malfunction.
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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 )
Page 291 of 684
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
Page 292 of 684

2924-5. Using the driving support systems
RC350/RCF_U (OM24636U)
■The pre-collision system is operational when
The pre-collision system is enabled and the following conditions are met:
●Pre-collision warning:
• Vehicle speed is greater th an about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Pre-collision brake assist:
• The VSC system is not disabled.
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running
ahead of you is greater than about 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The VSC system is not disabled.
• Vehicle speed is greater th an about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Suspension control:
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 19 mph (30 km/h).
●Steering control:
• The VSC system is not disabled.
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle runningahead of you is greater than about 19 mph (30 km/h).
Page 293 of 684

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 )
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2944-5. Using the driving support systems
RC350/RCF_U (OM24636U)
■Certification
For vehicles sold in the U.S.A.
FCC ID: BABFT0041A
CAUTION: Radio Frequency Radiation Exposure
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled
environment.
This equipment should be installed and oper ated keeping the radiator at least 20cm or
more away from person’s body (excluding ex tremities: hands, wrists, feet and ankles).
Co-location: This transmitter must not be co-located or operated in conjunction with any
other antenna or transmitter.
This device complies with part 15 of the FC C Rules. Operation is subject to the following
two conditions: (1) This device may not caus e harmful interference, and (2) this device
must accept any interference received, incl uding interference that may cause undesired
operation.
FCC WARNING
Changes or modifications not expressly approved by the party responsible for compli-
ance could void the user's authority to operate the equipment.
For vehicles sold in Canada
IC: 2024B-FT0041A
This device complies with Industry Canada licence-exempt RSS standard(s). Operation
is subject to the following two conditions: (1) this device may not cause interference, and
(2) this device must accept any interference, including interference that may cause
undesired operation of the device.
Page 295 of 684

2954-5. Using the driving support systems
4
Driving
RC350/RCF_U (OM24636U)
WA R N I N G
■Limitations of the pre-collision system
●The driver is solely responsible for safe driving. Always drive safely, taking care to
observe your surroundings.
Never use the pre-collision safety system instead of normal braking operations. This
system is not designed to avoid or reduce collisions in every situation. Overly relying
on the system or entrusting it with safety may lead to an accident resulting in death or
serious injury.
Although this system is designed to suppor t in avoiding a collision or reducing the
damage of a collision, its effectiveness may change according to various conditions
( P. 292, 293). Therefore, the system may not always provide the same perfor-
mance. Also, pre-collision braking function may not operate depending on the oper-
ations of the driver. If the driver is stepping on the brake pedal or is operating the
steering wheel, the system may determine th at the driver is taking evasive action and
pre-collision braking func tion may not operate.
●As the pre-collision system is designed to assi st the driver in safe driving, it may oper-
ate under sporty driving conditions, whic h may cause an accident. For this reason
under sporty driving conditions, it is reco mmended that this system be disabled by
using the PCS OFF switch.
■Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surr ounding area to a strong impact.
If the sensor moves even slightly off posi tion, the system may become inaccurate or
malfunction. If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by your Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding area.
●Do not modify or paint the sensor and grille cover.
●If the radar sensor needs to be replaced, contact your Lexus dealer.
Page 296 of 684

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.