
2634-5. Using the driving support systems
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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.

2674-5. Using the driving support systems
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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

2684-5. Using the driving support systems
IS300h_EE(OM53B95E)
When driving on a road surface that is bright due to reflected light
When driving in a location where the light level changes rapidly, such as the
entrance to or exit from a tunnel
When sunlight or the headlights of oncoming vehicles are shining directly into
the camera lens
When driving on roads that are branching or merging
When driving on a road surface that is wet due to rain, previous rainfall, stand-
ing water, etc.
When the vehicle experiences strong up-and-down motion such as when driv-
ing on an extremely rough road or on a seam in the pavement
When headlight brightness at nighttime is reduced due to dirt on the lenses, or
when the headlights are misaligned
When driving on winding roads or roads that are uneven
When driving on rough or unpaved roads
When changing the tires
Depending on the tires used, sufficient performance may not be maintainable.
Warning messages for the LDA system
Warning messages are used to indicate a system malfunction or to inform the
driver of the need for caution while driving. (P. 518)

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.

2954-5. Using the driving support systems
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Driving
IS300h_EE(OM53B95E)
If the vehicle gets stuck in fresh snow or mud, the TRC and VSC systems
may reduce power from the hybrid system to the wheels. Pressing VSC
OFF switch to turn the system off may make it easier for you to rock the
vehicle in order to free it.
Turning off the TRC system only
To turn the TRC system off,
quickly press and release the
switch.
The “TRC OFF” will be shown
on the multi-information display.
Press the switch again to turn the
system back on.
Turning off both TRC and VSC systems
To turn the TRC and VSC sys-
tems off, press and hold the
switch for more than 3 seconds
while the vehicle is stopped.
The VSC OFF indicator light will
come on and the “TRC OFF” will
be shown on the multi-informa-
tion display.
*
Press the switch again to turn the
systems back on.
*: On vehicles with pre-crash safety system, pre-crash brake assist and pre-
crash braking will also be disabled. The pre-crash safety system warning
light will come on and the message will be shown on the multi-information
display. (P. 299)
Disabling the TRC/VSC systems

2994-5. Using the driving support systems
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Driving
IS300h_EE(OM53B95E)
Pre-crash warning
When a high possibility of a fron-
tal collision is detected, the pre-
crash safety system warning light
flashes, a buzzer sounds and a
message is shown on the multi-
information display to urge the
driver to take evasive action.
Pre-crash brake assist
When there is a high possibility of a frontal collision, the system
applies greater braking force in relation to how strongly the brake
pedal is depressed. The system may not warn the driver using a warn-
ing light, warning display and buzzer when the system detects and
judges braking operations.
Pre-crash braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automati-
cally applied to reduce the collision speed.
Suspension control (vehicles with Adaptive Variable Suspension Sys-
tem)
PCS (Pre-Crash Safety system)
: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes
are automatically engaged to lessen impact as well as vehicle damage.
The pre-crash safety system can be turned on and off as necessary by
operating the switch. (P. 301)

3014-5. Using the driving support systems
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Driving
IS300h_EE(OM53B95E)
Enabled
Disabled
The pre-crash safety system warning
light comes on when pre-crash
safety system is disabled.
The radar sensor detects vehicles or
other obstacles on or near the road
ahead and determines whether a
collision is imminent based on the
position, speed, and heading of the
obstacles.
Disabling pre-crash safety system
1
2
Radar sensor