2015 Lexus GS350 lane assist

GS350_OM_OM30F69U_(U)
2274-5. Using the driving support systems
4
Driving
■Automatic cancelation of constant speed control
The cruise control will stop maintaining the vehicle speed in the following situations:
●Actual vehicle speed is more than approximately 10 mph (16 km/h) below the set
vehicle speed.
At this time, the memorized set speed is not retained.
●Vehicle speed falls below approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is turned off by pressing the VSC OFF switch.
■When the LKA (Lane-Keeping Assist) will be activated
Using the radar cruise control in vehicle-to-vehicle distance control mode, lane
keeping assist function is activated.
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-to-vehicle
distance control operates properly. (Some obstructions, such as snow, ice and plastic
objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is canceled if an obstruction is detected.
■Warning messages and buzzers for dynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or to
inform the driver of the need for caution while driving. (P. 4 8 1 ) Grille cover
Radar sensor
1
2

233
GS350_OM_OM30F69U_(U)4-5. Using the driving support systems
4
Driving
LKA (Lane-Keeping Assist)
While driving on a freeway or motor highway that has lane markers and
no sharp curves, the system recognizes the lanes using a camera located
above the inside rear view mirror as a sensor to assist the driver with stay-
ing in the lane. The LKA system has two functions.
Camera sensor

: If equipped
Summary of functions

234
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
Lane departure warning function
If the system judges that the vehicle may deviate from its lane, it alerts
the driver using beeping, screen displays and a sensory warning
* given
via the steering wheel.
*: A slight steering torque is applied for a short period of time in the direction of
the center of the lane.
Lane keeping assist function
• This function will be active when the vehicle-to-vehicle distance con-
trol mode of the cruise control (P. 218) is set with vehicle speed
above approximately 45 mph (72 km/h) and while the lane depar-
ture warning function is active.
• When the lane keeping assist function is active, a slight steering
torque will be applied, to help the driver maintain the vehicle inside
the lane.
The lane keeping assist function will be temporarily canceled if the steering
wheel is not operated, or if you continue driving with your hands lightly touch-
ing the steering wheel. (P. 2 3 8 )
Functions included in the LKA
1
2

236
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
■Lane departure warning function
●When the vehicle speed is approximately 30 mph (48 km/h) or
more
●When the lane width is more than approximately 9.8 ft. (3.0 m)
●When driving on a straight road or through a curve with a radius of
more than approximately 394 ft. (120 m)
■Lane keeping assist function
●When the vehicle speed is between approximately 45 and 112 mph
(72 and 180 km/h)
●When the vehicle-to-vehicle distance mode of the radar cruise
control is on, and the set vehicle speed is approximately 45 mph (72
km/h) or more (the function will not operate when the radar cruise
control is in set speed mode)
●When the lane width is between approximately 9.8 and 13.1 ft.
(3.0 and 4.0 m)
●When driving on a straight road or through a curve with a radius of
more than approximately 656 ft. (200 m)
Operating conditions for each function

GS350_OM_OM30F69U_(U)
2374-5. Using the driving support systems
4
Driving
When the LKA system is on, the lane line display and steering wheel dis-
play are shown.
Lane keeping assist function
operation indication
Steering wheel displayed:
Indicates that the function is currently
operating. (If the lane departure warn-
ing operates at this time, the steering
wheel flashes orange.)
Steering wheel not displayed:
Indicates that the function is not cur-
rently operating. (When the lane
keeping assist function is canceled,
the buzzer will beep twice.)
Dynamic radar cruise control dis-
play
Lane departure warning function
indication (when the inside of the
white line is white):
The function has recognized lane
markers. (If the lane departure warn-
ing operates at this time, the lines flash
orange.)
Lane departure warning function
indication (when the inside of the
white line is black):
A lane marker is not recognized by
the system, or the LKA system func-
tions are temporarily canceled.
Indication on the multi-information display
1
2
3
4

238
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
■Temporary cancelation of the LKA system functions
If any of the following occurs, the LKA system functions will be temporarily canceled.
The functions will resume after the necessary operating conditions have returned.
●The steering wheel is turned as far as necessary to cause the vehicle to change
lanes.
●When the system detects no-handed driving. (The lane keeping assist function will
be temporarily canceled, but the lane departure warning function will continue.)
●The turn signal lever is operated.
●The vehicle speed deviates from the operating range of the LKA system functions.
(The buzzer will beep twice when the lane keeping assist function is being can-
celed.)
●When the lane lines cannot be recognized while driving. (The buzzer will beep
twice when the lane keeping assist function is being canceled.)
●The wiper switch is set on high speed mode or is set on AUTO mode with wipers
operating at high speed. (The lane keeping assist function will be temporarily can-
celed, but the lane departure warning function will continue.)
●If the vehicle crosses a line for approximately half a minute or more. (The lane keep-
ing assist function will be temporarily canceled, but the lane departure warning
function will continue.)
●When the lane departure warning function is activated.
The lane departure warning function will not operate again for a several seconds
after it has been activated, even if the vehicle leaves the lane again.
■The lane departure warning
It may be difficult to feel the sensory warning depending on the road conditions.
■No-handed driving warning
If the steering wheel is not operated for approximately 15 seconds on a straight road
or approximately 5 seconds on a curve, the buzzer will beep twice, indicators on the
multi-information display will flash, and the lane keeping assist function will be tem-
porarily canceled. If you drive the vehicle with your hands lightly touching the steer-
ing wheel, this may also be detected as no-handed driving.
■After the vehicle has been parked in the sun
The LKA system functions may not be available and a warning message (P. 4 8 9 )
will be displayed for a while after driving has started. In such cases, turn the LKA sys-
tem off and turn it on again after normal temperature returns. When the temperature
in the cabin decreases and the temperature around the camera sensor (P. 2 3 3 )
becomes suitable for its operation, the functions will begin to operate.

GS350_OM_OM30F69U_(U)
2394-5. Using the driving support systems
4
Driving
■If there are lane markers on only one side of the vehicle
The lane keeping assist function will not operate. Also, 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 conditions, the LKA system functions may not operate, or it may not
be possible to ensure adequate performance. Also, the camera sensor may be
unable to recognize lane lines causing the lane departure warning function to oper-
ate incorrectly, or the lane keeping assist function may not operate properly. 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 lanes 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 marker” or
stones
●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
●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, standing
water, etc.
●When the vehicle experiences strong up-and-down motion such as when driving
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 with a strong crosswind

GS350_OM_OM30F69U_(U)
2534-5. Using the driving support systems
4
Driving
■Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehi-
cle speed increases. However, when both TRAC/VSC systems are turned off, the
systems will not turn on even when vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheat-
ing when there is frequent steering input over an extended period of time. The steer-
ing wheel may feel heavy as a result.
* Should this occur, refrain from excessive
steering input or stop the vehicle and turn the engine off. The EPS system should
return to normal within 10 minutes.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a warning
message will be shown on the multi-information display.