LEXUS IS 300 (2019 year). Instruction - part 15

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WARNING

■

When to disable the pre-collision system
In the following situations, disable the system, as it may not operate properly, possibly

leading to an accident resulting in death or serious injury:

●

When the vehicle is being towed

●

When your vehicle is towing another vehicle

●

When transporting the vehicle via truck, boat, train or similar means of transportation

●

When the vehicle is raised on a lift with the engine running and the tires are allowed to

rotate freely

●

When inspecting the vehicle using a drum tester such as a chassis dynamometer or

speedometer tester, or when using an on vehicle wheel balancer

●

When a strong impact is applied to the front bumper or front grille, due to an accident

or other reasons

●

If the vehicle cannot be driven in a stable manner, such as when the vehicle has been

in an accident or is malfunctioning

●

When the vehicle is driven in a sporty manner or off-road

●

When the tires are not properly inflated

●

When the tires are very worn

●

When tires of a size other than specified are installed

●

When tire chains are installed

●

When a compact spare tire or an emergency tire puncture repair kit is used

●

If equipment (snow plow, etc.) that may obstruct the radar sensor or camera sensor is

temporarily installed to the vehicle

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Enabling/disabling the pre-collision system

The pre-collision system can be enabled/disabled on 

 (

P. 103) of the

multi-information display.

The system is automatically enabled each time the engine switch is turned to IGNI-

TION ON mode.

If the system is disabled, the PCS
warning light will turn on and a mes-
sage will be displayed on the multi-
information display.

■

Changing the pre-collision warning timing
The pre-collision warning timing can be changed on 

 (

P. 103) of the

multi-information display.

The operation timing setting is retained when the engine switch is turned off.

Far

The warning will begin to operate

earlier than with the default timing.

Middle

This is the default setting.

Near

The warning will begin to operate

later than with the default timing.

Changing settings of the pre-collision system

1

2

3

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Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a

frontal collision with a vehicle or pedestrian is high.
Each function is operational at the following speeds:

●

Pre-collision warning:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For

detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10

and 80 km/h].)

• The relative speed between your vehicle and the vehicle or pedestrian ahead is

approximately 7 mph (10 km/h) or more.

●

Pre-collision brake assist: 
• Vehicle speed is between approximately 20 and 110 mph (30 and 180 km/h). (For

detecting a pedestrian, vehicle speed is between approximately 20 and 50 mph

[30 and 80 km/h].)

• The relative speed between your vehicle and the vehicle or pedestrian ahead is

approximately 20 mph (30 km/h) or more.

●

Pre-collision braking:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For

detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10

and 80 km/h].)

• The relative speed between your vehicle and the vehicle or pedestrian ahead is

approximately 7 mph (10 km/h) or more.

The system may not operate in the following situations:

●

If a battery terminal has been disconnected and reconnected and then the vehicle has

not been driven for a certain amount of time

●

If the shift lever is in R

●

If VSC is disabled (only the pre-collision warning function will be operational)

■

Pedestrian detection function

■

Cancelation of the pre-collision braking
If either of the following occur while the pre-collision braking function is operating, it will

be canceled:

●

The accelerator pedal is depressed strongly.

●

The steering wheel is turned sharply or abruptly.

The pre-collision system detects pedestrians

based on the size, profile, and motion of a

detected object. However, a pedestrian may not

be detected depending on the surrounding

brightness and the motion, posture, and angle of

the detected object, preventing the system from

operating properly. (

P. 238)

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Conditions under which the system may operate even if there is no possibility of a colli-

sion

●

In some situations such as the following, the system may determine that there is a possi-

bility of a frontal collision and operate.
• When passing a vehicle or pedestrian

• When changing lanes while overtaking a preceding vehicle

• When overtaking a preceding vehicle that is changing lanes

• When rapidly closing on a vehicle ahead

• If the front of the vehicle is raised or lowered, such as when the road surface is

uneven or undulating

• When approaching objects on the roadside, such as guardrails, utility poles, trees, or

walls

• When driving on a narrow path surrounded by a structure, such as in a tunnel or on

an iron bridge

• When overtaking a preceding vehicle that

is making a left/right turn

• When passing a vehicle in an oncoming

lane that is stopped to make a right/left turn

• When driving on a road where relative

location to vehicle ahead in an adjacent

lane may change, such as on a winding

road

• When there is a vehicle, pedestrian, or

object by the roadside at the entrance of a

curve

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• When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion

on the road surface or roadside

• When rapidly closing on an electric toll gate barrier, parking area barrier, or other

barrier that opens and closes

• When using an automatic car wash

• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead

• When driving through steam or smoke

• When there are patterns or paint on the road or a wall that may be mistaken for a

vehicle or pedestrian

• When driving near an object that reflects radio waves, such as a large truck or

guardrail

• When driving near a TV tower, broadcasting station, electric power plant, or other

location where strong radio waves or electrical noise may be present

• When a crossing pedestrian approaches

very close to the vehicle

• When passing through a place with a low

structure above the road (low ceiling, traffic

sign, etc.)

• When passing under an object (billboard,

etc.) at the top of an uphill road

• When driving through or under objects

that may contact the vehicle, such as thick

grass, tree branches, or a banner

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Situations in which the system may not operate properly

●

In some situations such as the following, a vehicle may not be detected by the radar

sensor and camera sensor, preventing the system from operating properly:
• If an oncoming vehicle is approaching your vehicle

• If a vehicle ahead is a motorcycle or bicycle

• When approaching the side or front of a vehicle

• If a preceding vehicle has a small rear end, such as an unloaded truck

• If a vehicle ahead is carrying a load which protrudes past its rear bumper

• If a vehicle ahead is irregularly shaped, such as a tractor or side car

• If the sun or other light is shining directly on a vehicle ahead

• If a vehicle cuts in front of your vehicle or emerges from beside a vehicle

• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, accelera-

tion or deceleration)

• When suddenly cutting behind a preceding vehicle

• When driving in inclement weather such as heavy rain, fog, snow or a sandstorm

• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead

• When driving through steam or smoke

• When driving in a place where the surrounding brightness changes suddenly, such

as at the entrance or exit of a tunnel

• When a very bright light, such as the sun or the headlights of oncoming traffic, shines

directly into the camera sensor

• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a

tunnel

• If a preceding vehicle has a low rear end,

such as a low bed trailer

• If a vehicle ahead has extremely high

ground clearance

• When a vehicle ahead is not directly in front

of your vehicle

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• After the engine has started the vehicle has not been driven for a certain amount of

time

• While making a left/right turn and for a few seconds after making a left/right turn

• While driving on a curve and for a few seconds after driving on a curve

• If your vehicle is skidding

• If the wheels are misaligned

• If a wiper blade is blocking the camera sensor

• The vehicle is wobbling.

• The vehicle is being driven at extremely high speeds.

• When driving on a hill 

• If the radar sensor or camera sensor is misaligned

●

In some situations such as the following, sufficient braking force may not be obtained,

preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake

parts are extremely cold, extremely hot, or wet

• If the vehicle is not properly maintained (brakes or tires are excessively worn,

improper tire inflation pressure, etc.)

• When the vehicle is being driven on a gravel road or other slippery surface

●

Some pedestrians such as the following may not be detected by the radar sensor and

camera sensor, preventing the system from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5

ft. (2 m)

• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), making their sil-

houette obscure

• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part

of their body

• Pedestrians who are bending forward or squatting

• Pedestrians who are pushing a stroller, wheelchair, bicycle or other vehicle

• Groups of pedestrians which are close together

• Pedestrians who are wearing white and look extremely bright

• Pedestrians in the dark, such as at night or while in a tunnel

• Pedestrians whose clothing appears to be nearly the same color or brightness as

their surroundings

• Pedestrians near walls, fences, guardrails, or large objects

• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road

• Pedestrians who are walking fast

• Pedestrians who are changing speed abruptly

• Pedestrians running out from behind a vehicle or a large object

• Pedestrians who are extremely close to the side of the vehicle (outside rear view

mirror, etc.)

• If the front of the vehicle is raised or low-

ered

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■

If the PCS warning light flashes or illuminates and a warning message is displayed on

the multi-information display
The pre-collision system may be temporarily unavailable or there may be a malfunction

in the system.

●

In the following situations, the warning light will turn off, the message will disappear and

the system will become operational when normal operating conditions return:
• When the radar sensor or camera sensor or the area around either sensor is hot,

such as in the sun

• When the radar sensor or camera sensor or the area around either sensor is cold,

such as in an extremely cold environment

• When a front sensor is dirty or covered with snow, etc.

• When the part of the windshield in front of the camera sensor is fogged up or cov-

ered with condensation or ice (Defogging the windshield: 



P. 422)

• If the camera sensor is obstructed, such as when the hood is open or a sticker is

attached to the windshield near the camera sensor

●

If the PCS warning light continues to flash or remains illuminated or the warning mes-

sage does not disappear even though the vehicle has returned to normal, the system

may be malfunctioning. Have the vehicle inspected by your Lexus dealer immediately.

■

If VSC is disabled

●

If VSC is disabled (

P. 303), the pre-collision brake assist and pre-collision braking

functions are also disabled.

●

The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake System

Unavailable” will be displayed on the multi-information display.

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When driving on highways and freeways with white (yellow) lines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering wheel to keep the vehicle in its lane.
The LDA system recognizes visible
white (yellow) lines with the camera
sensor on the upper portion of the front
windshield.

◆

Lane departure alert function

When the system determines that
the vehicle might depart from its
lane, a warning is displayed on the
multi-information display, and either
the warning buzzer sounds or the
steering wheel vibrates to alert the
driver.

When the warning buzzer sounds or

the steering wheel vibrates, check

the surrounding road situation and

carefully operate the steering wheel

to move the vehicle back to the cen-

ter of the lane.

LDA (Lane Departure Alert with steering control)

Summary of functions

Functions included in LDA system

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◆

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.

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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 conditions 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 operations 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, curbs, 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 other 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 repairs, contact your Lexus dealer.

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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

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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 display 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 (yellow) lines or is
temporarily canceled.

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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 approximately 32 mph (50 km/h) or more.

• System recognizes white (yellow) lines.

• Width of traffic lane is approximately 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 following conditions are met in addition to the

operation conditions for the lane departure alert function.
• Setting for Steering Assist in 

 of the multi-information display is set to On. 

(

P. 103)

• Vehicle is not accelerated 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 approximately 32 mph (50 km/h) or more.

• Width of traffic lane is approximately 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 conditions are met again, operation of the function

is automatically restored. (

P. 245)

■

Steering control function
Depending on the vehicle speed, lane departure 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 feel steering wheel vibrations due to the road conditions etc.

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Hands off steering wheel warning

If the driver continues to keep their hands off of the steering wheel, a buzzer sounds and

a warning message and the symbol shown in the illustration are displayed on the multi-

information display. This warning also operates in the same way when the driver continu-

ously operates the steering wheel only a small 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.

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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 area 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 carrying 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 amount 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 lanes or crossed an intersection.

●

Snow tires, etc. are equipped.

■

Warning message
Warning messages are used to indicate a system malfunction or to inform the driver of

the need for caution while driving. (

P. 532)

■

Customization
P. 103