wheel Lexus GS350 2019 Service Manual

258
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.

GS350_300_OM_OM30G96U_(U)
2594-5. Using the driving support systems
4
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.

260
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

GS350_300_OM_OM30G96U_(U)
2614-5. Using the driving support systems
4
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.

262
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.

GS350_300_OM_OM30G96U_(U)
2634-5. Using the driving support systems
4
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.

GS350_300_OM_OM30G96U_(U)
2654-5. Using the driving support systems
4
Driving
■Customization
The following settings can be changed.
For how to change settings, refer to P. 549.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering assist functionTurn steering wheel assistance on and off
Vehicle sway warning functionTurn function on and off
Adjust alert sensitivity
Lane centering functionTurn function on and off

GS350_300_OM_OM30G96U_(U)
2774-5. Using the driving support systems
4
Driving
■Conditions under which the vehicle-to-vehicle distance control mode may not function
correctly
In the case of the following conditions, o perate the brake pedal (or accelerator pedal,
depending on the situ ation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system may not
operate properly.
●When the vehicle ahead of you decelerates suddenly
●When driving on a road surrounded by a struct ure, such as in a tunnel or on a bridge
●While the vehicle speed is decreasing to the set speed after the vehicle accelerates by
depressing the accelerator pedal
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)
●Preceding vehicle has an extremely high
ground clearance
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

294
GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
TVD (Torque Vectoring Differential) (GS F)
With the engine switch in IGNITION
ON mode, pressing the TVD switch
changes the TVD control mode.
The current TVD control mode will be
displayed on the meters.
STANDARD mode
This is the default mode and provides
an optimum balance of driving agility
and stability.
SLALOM mode
This mode emphasizes enhanced
steering response.
TRACK mode
This mode emphasiz
es stability for
high speed sporty driving.
The multi-information display shows the di stribution of driving force between the
right and left rear wheels. ( P. 119)
The TVD system distributes driving force (torque) between the right an\
d left
rear wheels automatically. This syst em contributes to enhanced steering
response while cornering and increased traction when exiting a corner, pro-
viding an agile driving experience.
Changing TVD control modes
1
2
3
TVD control status on the multi-information display

296
GS350_300_OM_OM30G96U_(U)4-5. Using the driving support systems
Driving assist systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the br
akes are applied suddenly, or if the
brakes are applied while drivin g on a slippery road surface
◆Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to contro l skidding when swerving suddenly or turning on
slippery road surfaces
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and pr event the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to prevent the vehicle from ro lling backward when starting on an
incline.
To help enhance driving safety and perf ormance, the following systems oper-
ate automatically in response to variou s driving situations. Be aware, however,
that these systems are supplementary and should not be relied upon too heav-
ily when operating the vehicle.