2019 Lexus GS350 Owner's Manual

GS350_300_OM_OM30G96U_(U)
2574-5. Using the driving support systems
4
Driving
◆Steering assist 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.
GS350/GS300: 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 dis-
played on the multi-information dis-
play and the warning buzzer sounds.
GS F: If the system detects that the
steering wheel has not been oper-
ated 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
function is temporarily canceled.
◆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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GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
◆Lane centering function
This function is linked with radar
cruise control and provides the
required assistance by operating the
steering wheel to keep the vehicle in
its current lane.
When radar cruise control is not
operating, the lane centering func-
tion does not operate.
GS350/GS300: 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 dis-
played on the multi-information dis-
play and the warning buzzer sounds.
GS F: If the system detects that the
steering wheel has not been oper-
ated 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
function is temporarily canceled.

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2594-5. Using the driving support systems
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Driving
WARNING
■Before using LKA system
Do not rely solely upon the LKA system. The LKA 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 LKA system by mistake
When not using the LKA system, use the LKA switch to turn the system off.
■Situations unsuitable for LKA system
Do not use the LKA 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 LKA system malfunctions and operations perf ormed 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.

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GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
Press the LKA switch to turn the LKA system on.
The LKA indicator illuminates and a messag
e is displayed on the multi-information
display.
Press the LKA switch again to turn the LKA system off.
When the LKA system is turned on or off, operation of the LKA system continues in
the same condition the next time the engine is started.
LKA indicator
The illumination condition of the
indicator informs the driver of the
system operation status.
Illuminated in white:
LKA system is operating.
Illuminated in green:
Steering wheel assistance of the steer-
ing assist function or lane centering
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 assist function or lane
centering function is operating.
Turning LKA system on
GS350/GS300GS F
Indications on multi-information display
1
2

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Driving
Lane departure alert function display
Displayed when the multi-information display is switched to the driving assist
system information screen.
■Operation conditions of each function
●Lane departure alert function
This function operates when all of the following conditions are met.
• LKA 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. 264)
●Steering assist 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 the multi-information display is set to “On”.
(  P. 106, 114)
• 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 (Pre-Collision System) are not operating.
• TRAC or VSC is not turned off.
• GS F: Hands off steering wheel alert is not displayed. ( P. 263)
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.

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GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
●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. 106, 114)
• 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. 264)
●Lane centering function
This function operates when all of the following conditions are met.
• LKA is turned on.
• Setting for “Steering Assist” and “Lane Center” in of the multi-information display are set to “On”. ( P. 106, 114)
• System recognizes white (yellow) lines.
• Dynamic radar cruise control with full-speed range is operating.
• Width of traffic lane is approximately 8.2 to 13.5 ft. (2.5 to 4.1 m).
• 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 656 ft. (200 m).
• No system malfunctions are detected. ( P. 264)
• Vehicle does not accelera te or decelerate 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 (Pre-Collision System) are not operating.
• TRAC or VSC is not turned off.
• GS F: Hands off steering wheel alert is not displayed. ( P. 263)
• Steering assist function is not operating.
■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. 261)
■Steering assist function/lane centering 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.

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Driving
■Hands off steering wheel warning
GS350/GS300:
Depending on the vehicle and road conditions, the warning may not operate.
GS F:
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. When the system determines that the driver has
removed their hands from the steering wheel
while the steering assist function or lane center-
ing function is operating, a warning message
urging the driver to hold the steering wheel and
the symbol shown in the illustration are dis-
played on the multi-information display.
If the driver continues to keep their hands off of
the steering wheel, a buzzer sounds and a warn-
ing message and the symbol shown in the illus-
tration are displayed on the multi-information
display. This warning al so operates in the same
way when the driver cont inuously operates the
steering wheel only a small amount. Always
keep your hands on the steering wheel when
using this system, regardless of warnings.
When the system determines that the driver has
removed their hands from the steering wheel
while the steering assist function or lane center-
ing function is operating, a warning message
urging the driver to hold the steering wheel and
the symbol shown in the illustration are dis-
played on the multi- information display.
If the driver continues to keep their hands off of
the steering wheel, a warning message and the
symbol shown in the illustration are displayed on
the multi-information display, and the function is
temporarily canceled. This warning also oper-
ates in the same way when the driver continu-
ously operates the steering wheel only a small
amount. Always keep your hands on the steer-
ing wheel when using th is system, regardless of
warnings.
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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GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
■White (yellow) lines are only on one side of road
The LKA system will not operate for the side
on which white (yellow) lines could not be
recognized.
■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. 444)