Lexus IS300 2019 Owner's Manual / 2019 IS300,IS350 OWNER'S MANUAL (OM53E71U)

2414-5. Using the driving support systems
4
Driving
IS350 AWD/IS350/IS300 AWD/IS300_U
◆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 warning
buzzer sounds.
◆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.

2424-5. Using the driving support systems
IS350 AWD/IS350/IS300 AWD/IS300_U
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 (yellow) 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.
■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.

2434-5. Using the driving support systems
4
Driving
IS350 AWD/IS350/IS300 AWD/IS300_U
Press the LDA switch to turn the LDA
system on.
The LDA indicator illuminates and a
message is displayed on the multi-infor-
mation display.
Press the LDA switch again to turn the
LDA system off.
When the LDA system is turned on or
off, operation of the LDA system contin-
ues in the same condition the next time
the engine is started.
Turning LDA system on

2444-5. Using the driving support systems
IS350 AWD/IS350/IS300 AWD/IS300_U
LDA indicator
The illumination condition of the
indicator informs the driver of the
system operation status.
Illuminated in white:
LDA system is operating.
Illuminated in green:
Steering wheel assistance of the steer-
ing control function is operating.
Flashing in orange:
Lane departure alert function is operat-
ing.
Operation display of steering wheel
operation support
Indicates that steering wheel assistance of the steering control function is
operating.
Lane departure alert function display
Displayed when the multi-information disp lay is switched to the driving assist
system information screen.
Indications on multi-information display
1
2
3
Inside of displayed white lines is
whiteInside of displayed white lines is
black
Indicates that the system is recognizing
white (yellow) lines. When the vehicle
departs from its lane, the white line dis-
played on the side the vehicle departs
from flashes orange. Indicates that the system is not able to
recognize white (ye
llow) lines or is
temporarily canceled.

2454-5. Using the driving support systems
4
Driving
IS350 AWD/IS350/IS300 AWD/IS300_U
■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 straight road or around a gentle curve with a radius of more
than approximately 492 ft. (150 m).
• No system malfunctions are detected. ( P. 525)
●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. 103)
• Vehicle is not accelera ted or decelerated by a certain 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.
●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. 103)
• 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. 525)
■Temporary cancellation of functions
When the operation conditions are no longer met, a function may be temporarily can-
celed. However, when the operation conditio ns are met again, operation of the function
is automatically restored. ( P. 245)
■Steering control function
Depending on the vehicle speed, lane depart ure situation, road conditions, etc., the
driver may not feel the function is operating 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.

2464-5. Using the driving support systems
IS350 AWD/IS350/IS300 AWD/IS300_U
■Hands off steering wheel warning
If the driver continues to keep their hands of f of the steering wheel, a buzzer sounds and
a warning message and the symb ol shown in the illustration are displayed on the multi-
information display. This warning also operat es in the same way when the driver continu-
ously operates the steering wheel only a sm all amount. Always keep your hands on the
steering wheel when using this system, regardless of warnings.
Depending on the vehicle and road conditions, the warning may not operate.
■Vehicle sway warning function
Depending on the vehicle and road conditions, the warning may not operate.
■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. When the system determines that the driver has
removed their hands from the steering wheel
while the steering control function is operating,
a warning message urging the driver to hold the
steering wheel and the symbol shown in the
illustration are displayed on the multi-informa-
tion display.
When the system determines that the vehicle is
swaying while the vehicle sway warning function
is operating, a buzzer sounds and a warning
message urging the driver to rest and the sym-
bol shown in the illustration are simultaneously
displayed on the multi-information display.

2474-5. Using the driving support systems
4
Driving
IS350 AWD/IS350/IS300 AWD/IS300_U
■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 tilts 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. 532)
■Customization
P. 103

2484-5. Using the driving support systems
IS350 AWD/IS350/IS300 AWD/IS300_U
In vehicle-to-vehicle distance control mode, the vehicle automatically a\
cceler-
ates and decelerates to match the speed changes of the preceding vehicle even
if the accelerator pedal is not depressed. In constant speed control mode, the
vehicle runs at a fixed speed.
Use the dynamic radar cruise control on freeways and highways.
●Vehicle-to-vehicle distance control mode ( P. 251)
●Constant speed control mode ( P. 256)
Vehicle-to-vehicle distance switch
Display
Set speed
Indicators
Cruise control switch
Dynamic radar cruise control
Summary of functions
1
2
3
4
5

2494-5. Using the driving support systems
4
Driving
IS350 AWD/IS350/IS300 AWD/IS300_U
WARNING
■Before using dynamic radar cruise control
●Driving safely is the sole responsibility of the driver. Do not rely solely on the system,
and drive safely by always paying ca reful attention to your surroundings.
●The dynamic radar cruise control provides driving assistance to reduce the driver’s
burden. However, there are limitatio ns to the assistance provided.
Read the following conditions carefully. Do not overly rely on this system and always
drive carefully.
• When the sensor may not be correctly detecting the vehicle ahead: P. 258
• Conditions under which the vehicle-to-vehicle distance control mode may not function correctly: P. 259
●Set the speed appropriately depending on the speed limit, traffic flow, road condi-
tions, weather conditions, etc. The driver is responsible for checking 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.
Therefore, 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, resulting in death or serious injury.
●Switch the dynamic radar cruise control off using the “ON/OFF” button when not in
use.
■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 inattentive 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.

2504-5. Using the driving support systems
IS350 AWD/IS350/IS300 AWD/IS300_U
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