
2624-5. Using the driving support systems
IS300h_EE(OM53B95E)
Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set speed. If automatic deceleration/acceleration is not appro-
priate, adjust the vehicle speed, as well as the distance between your vehicle
and vehicles ahead by applying the brakes etc.
Cautions regarding the driving assist systems
Observe the following precautions.
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 intended to help the driver in deter-
mining the following distance between the driver’s own vehicle and a desig-
nated vehicle traveling ahead. It is not a mechanism that allows careless or
inattentive driving, and it is not a system that can assist the driver in low-visi-
bility conditions. It is still necessary for driver to pay close attention to the
vehicle’s surroundings.
Assisting the driver to judge proper following distance
The dynamic radar cruise control determines whether the following distance
between the driver’s own vehicle and a designated vehicle traveling ahead is
appropriate or not. 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 situa-
tion.
Assisting the driver to operate the vehicle
The dynamic radar cruise control has no capability to prevent or avoid a colli-
sion 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 appropri-
ately in order to ensure the safety of all involved.
To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON/OFF” button when not in use.
Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident
resulting in death or serious injury.
In heavy traffic
On roads with sharp bends
On winding roads
On slippery roads, such as those 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 expressways
When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
When an approach warning buzzer is heard often
When your vehicle is towing a trailer or during emergency towing

2634-5. Using the driving support systems
4
Driving
IS300h_EE(OM53B95E)
CAUTION
When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are
in front of you.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (P. 254) will not be activated, and a fatal or serious acci-
dent may result.
Vehicles that cut in suddenly
Vehicles traveling at low speeds
Vehicles that are not moving
Vehicles with small rear ends (trailers with no load on board etc.)
Motorcycles traveling in the same lane
Conditions under which the vehicle-to-vehicle distance control may not func-
tion correctly
Apply the brakes as necessary in the following conditions as the radar sensor
may not be able to correctly detect vehicles ahead, and a fatal or serious acci-
dent may result:
When water or snow thrown up by a the surrounding vehicles hinders the
functioning of the sensor
When your vehicle is pointing upwards (caused by a heavy load in the trunk
etc.)
When the road curves or when the lanes are narrow
When steering wheel operation or your position in the lane is unstable
When the vehicle ahead of you decelerates suddenly
Handling the radar sensor
Observe the following to ensure the cruise control system can function effec-
tively.
Otherwise, the system may not function correctly and could result in an acci-
dent.
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 dam-
age them.
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If
the sensor or surrounding area is subject to a strong impact, always have the
area inspected and adjusted by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
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.
Do not replace them with non-genuine parts.

2654-5. Using the driving support systems
4
Driving
IS300h_EE(OM53B95E)
Press the LDA switch to activate
the system.
The LDA indicator and lane lines
will come on.
Press the switch again to turn the
LDA system off.
The LDA system will remain on or
off even if the power switch is
turned to ON mode.
When the vehicle speed is approximately 50 km/h (32 mph) or more
When the lane width is more than approximately 2.5 m (8.2 ft.)
When driving on a straight road or through a curve with a radius of
more than approximately 100 m (328 ft.)
Turning the LDA system on
Operating conditions

2674-5. Using the driving support systems
4
Driving
IS300h_EE(OM53B95E)
Temporary cancelation of the LDA system functions
If any of the following occurs, the LDA system functions will be temporarily
canceled. The functions will resume after the necessary operating conditions
have returned.
The turn signal lever is operated.
The vehicle speed deviates from the operating range of the LDA system func-
tions.
When the lane lines cannot be recognized while driving.
When the lane departure warning sounds.
The lane departure warning function will not operate again for a several sec-
onds after it has been activated, even if the vehicle leaves the lane again.
The lane departure warning
Depending on the audio system sound level or air conditioning fan noise while
the audio system or air conditioning system is in use, it may be difficult to hear
the warning sound.
After the vehicle has been parked in the sun
The LDA system may not be available and a warning message (P. 518) will be
displayed for a while after driving has started. When the temperature in the cabin
decreases and the temperature around the camera sensor (P. 264) becomes suit-
able for its operation, the functions will begin to operate.
If there are lane markers on only one side of the vehicle
The lane departure warning will not operate for the side on which lane markers
could not be recognized.
Conditions in which the function may not operate correctly
In the following situations, the camera sensor may be unable to recognize lane
markers causing the lane departure warning function to operate incorrectly. How-
ever, this does not indicate a malfunction.
When driving through an area with no lane markers, such as a tollbooth, a
crossing or before a ticket checkpoint
When driving on a sharp curve
When lane markers are extremely narrow or extremely wide
When the vehicle leans to one side an unusual amount due to a heavy load or
improper tire inflation pressure
When the following distance between your vehicle and the vehicle ahead is
extremely short
When the lane markers are yellow (These may be more difficult for the system
to recognize compared to white markers.)
When the lane markers are broken, Botts’ dots (raised pavement markers) or
stones
When the lane markers are on a curb etc.
When lane markers are obscured or partially obscured by sand, dirt, etc.
When there are shadows on the road running parallel with lane markers, or if a
shadow covers the lane markers
When driving on a particularly bright road surface, such as concrete

2754-5. Using the driving support systems
4
Driving
IS300h_EE(OM53B95E)
You can change the warning beep volume and Lexus Display Audio
screen operating conditions.
Press the “MENU” button on the Lexus Display Audio controller. (P.
318)
Select “Setup” on the “Menu” screen.
Select “Vehicle” on the “Setup” screen.
Select “LEXUS park assist” on the “Vehicle settings” screen.
Select the desired button.
The alert volume can be
adjusted.
On or off can be selected for
Lexus parking assist-sensor
display.
Front or rear center sensors
display and tone indication can
be set.
The Lexus parking assist-sensor can be operated when
Front center sensors:
• The power switch is in ON mode.
• The shift lever is in a position other than P or R.
• The vehicle speed is less than about 10 km/h (6 mph).
Front corner sensors:
• The power switch is in ON mode.
• The shift lever is in a position other than P.
• The vehicle speed is less than about 10 km/h (6 mph).
(At any speed when the shift lever is in R)
Rear corner and rear center sensors:
• The power switch is in ON mode.
• The shift lever is in R.
Lexus parking assist-sensor display
When an obstacle is detected while the rear view monitor system is in use, the
warning indicator will appear in the top right of the screen even if the display set-
ting has been set to off.
Setting up Lexus parking assist-sensor
1
2
3
4
5
1
2
3

2764-5. Using the driving support systems
IS300h_EE(OM53B95E)
Sensor detection information
The sensor’s detection areas are limited to the areas around the vehicle’s front
corner and rear bumpers.
Certain vehicle conditions and the surrounding 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
problem.)
• The sensor is frozen. (Thawing the 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 considerably 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 sensors 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 (lowered 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 particu-
lar 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 vehicle
The following situations may occur during use.
• Depending on the shape of the obstacle and other factors, the detection dis-
tance may shorten, or detection may be impossible.
• Obstacles may not be detected if they are too close to the sensor.
• There will be a short delay between obstacle detection and display. Even at
slow speeds, there is a possibility that the obstacle will come within the sen-
sor’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.

2784-5. Using the driving support systems
IS300h_EE(OM53B95E)
CAUTION
When using the Lexus parking assist-sensor
Observe the following precautions.
Failing to do so may result in the vehicle being unable to be driven safely and
possibly cause an accident.
Do not use the sensor at speeds in excess of 10 km/h (6 mph).
The sensors’ detection areas and reaction times are limited. When moving
forward or reversing, check the areas surrounding the vehicle (especially the
sides of the vehicle) for safety, and drive slowly, using the brake to control the
vehicle’s speed.
Do not install accessories within the sensors’ detection areas.
NOTICE
When using Lexus parking assist-sensor
In the following situations, the system may not function correctly due to a sen-
sor malfunction etc. Have the vehicle checked by any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
The Lexus parking assist-sensor operation display flashes, and a beep sounds
when no obstacles are detected.
If the area around a sensor collides with something, or is subjected to strong
impact.
If the bumper or grille collides with something.
If the display shows continuously without beeping, except when the buzzer
mute switch has been turned on.
If a display error occurs, first check the sensor.
If the error occurs even when there is no ice, snow or mud on the sensor, it is
likely that the sensor is malfunctioning.
Notes when washing the vehicle
Do not apply intensive bursts of water or steam to the sensor area.
Doing so may result in the sensor malfunctioning.

2884-5. Using the driving support systems
IS300h_EE(OM53B95E)
CAUTION
When using the rear view monitor system
The rear view monitor system is a supplemental device intended to assist the
driver when backing up. When backing up, be sure to check visually behind
and all around the vehicle before proceeding.
Observe the following precautions to avoid an accident that could result in
death or serious injuries.
Never depend on the rear view monitor system entirely when backing up. The
image and the position of the guide lines displayed on the screen may differ
from the actual state.
Use caution, just as you would when backing up any vehicle.
Be sure to back up slowly, depressing the brake pedal to control vehicle
speed.
The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to traffic
conditions, road surface conditions, vehicle condition, etc. when parking. It is
necessary to be fully aware of this before using the rear view monitor system.
When parking, be sure to check that the parking space will accommodate your
vehicle before maneuvering into it.
Do not use the rear view monitor system in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains
• When the trunk lid is not closed completely
• On roads that are not flat or straight, such as curves or slopes.
In low temperatures, the screen may darken or the image may become faint.
The image could distort when the vehicle is moving, or you may become
unable to see the image on the screen. Be sure to check direct visually and
with the mirrors all around the vehicle before proceeding.
If the tire sizes are changed, the position of the fixed guide lines displayed on
the screen may change.
The camera uses a special lens. The distances between objects and pedestrians
that appear in the image displayed on the screen will differ from the actual
distances.
(P. 281)