2013 Lexus GS300h lane assist

3124-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
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 16 km/h (10 mph) below
the set vehicle speed.
At this time, the memorized set speed is not retained.
Vehicle speed falls below approximately 40 km/h (25 mph).
VSC is activated.
TRC is activated for a period of time.
When the VSC or TRC 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. 841) Grille cover
Radar sensor
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3294-5. Using the driving support system
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Driving
GS450h_300h_OM_OM30D53E_(EE)
Dynamic radar cruise control with full-speed range can be set when
The shift lever is in D or range 4 or higher of S has been selected.
Range 4 or higher of D has been selected by using the paddle shift.
Vehicle speed is above approximately 50 km/h (30 mph).
Accelerating after setting the vehicle speed
The vehicle can accelerate normally. After acceleration, the set speed
resumes. However, during vehicle-to-vehicle distance control mode, the
vehicle speed may decrease below the set speed in order to maintain the dis-
tance to the vehicle ahead.
Automatic cancelation of vehicle-to-vehicle distance control
Vehicle-to-vehicle distance control driving is automatically canceled in the
following situations:
Actual vehicle speed falls below approximately 40 km/h (25 mph) when
there are no vehicle ahead.
The preceding vehicle leaves the lane when your vehicle is following at a
speed below 40 km/h (25 mph).
VSC is activated.
TRC is activated for a period of time.
When the VSC or TRC system is turned off by pressing the VSC OFF
switch.
The sensor cannot operate correctly because it is covered in some way.
The windshield wipers are operating at high speed (when the wiper switch
is set to AUTO mode or the high speed wiper operation).
When snow mode is set.
The parking brake is operated.
The vehicle is stopped by system control on a steep incline.
Pre-crash brake assist is activated.
The following are detected when the vehicle has been stopped by system
control:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The trunk or hood is opened.
• The vehicle has been stopped for about 3 minutes.
If vehicle-to-vehicle distance control driving is automatically canceled for
any other reason, there may be a malfunction in the system. Contact any

3314-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 16 km/h (10 mph) below
the set vehicle speed.
At this time, the memorized set speed is not retained.
Actual vehicle speed falls below approximately 40 km/h (25 mph).
VSC is activated.
TRC is activated for a period of time.
When the VSC or TRC 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 assistance control 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 or plastic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control with full-speed range is canceled if an obstruc-
tion is detected.
Warning messages and buzzers for dynamic radar cruise control with full-
speed range
Warning messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. (P. 841) Grille cover
Radar sensor
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3384-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
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 cam-
era located above the inside rear view mirror as a sensor to assist
the driver with staying in the lane. The LKA system has two func-
tions.
Camera sensor

: If equipped
Summary of functions

3394-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 direc-
tion of the center of the lane.
Lane keeping assist function
• This function will be active when the vehicle-to-vehicle dis-
tance control mode of the cruise control (P. 302) is set with
vehicle speed above approximately 72 km/h (45 mph) and
while the lane departure warning function is active.
• When the lane keeping assist function is active, a slight steer-
ing torque will be applied, to help the driver maintain the vehi-
cle 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 touching the steering wheel. (P. 343)
Functions included in the LKA
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3414-5. Using the driving support system
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Driving
GS450h_300h_OM_OM30D53E_(EE)
Lane departure warning function
When the vehicle speed is approximately 48 km/h (30 mph) or
more
When the lane width is more than approximately 3.0 m (9.8
ft.)
When driving on a straight road or through a curve with a
radius of more than approximately 120 m (394 ft.)
Lane keeping assist function
When the vehicle speed is between approximately 72 and 180 km/
h (45 and 112 mph)
When the vehicle-to-vehicle distance mode of the radar cruise
control is on, and the set vehicle speed is approximately 72
km/h (45 mph) or more (the function will not operate when the
radar cruise control is in set speed mode)
When the lane width is between approximately 3.0 and 4.0 m
(9.8 and 13.1 ft.)
When driving on a straight road or through a curve with a
radius of more than approximately 200 m (656 ft.)
Operating conditions for each function

3424-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
When the LKA system is on, the lane line display and steering
wheel display are shown.
Lane keeping assist function
operation indication
Steering wheel displayed:
Indicates that the function is cur-
rently operating. (If the lane depar-
ture warning operates at this time,
the steering wheel flashes orange.)
Steering wheel not displayed:
Indicates that the function is not
currently operating. (When the
lane keeping assist function is can-
celed, the buzzer will beep twice.)
Dynamic radar cruise control
display
Lane departure warning func-
tion indication (when the
inside of the white line is
white):
The function has recognized lane
markers. (If the lane departure
warning operates at this time, the
lines flash orange.)
Lane departure warning func-
tion indication (when the
inside of the white line is
black):
A lane marker is not recognized by
the system, or the LKA system
functions are temporarily canceled.
Indication on the multi-information display
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3434-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 func-
tion 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 func-
tion is being canceled.)
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 canceled, but the lane departure warning function will con-
tinue.)
If the vehicle crosses a line for approximately half a minute or more. (The
lane keeping 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 condi-
tions.
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 temporarily canceled. If you drive the vehicle
with your hands lightly touching the steering wheel, this may also be
detected as no-handed driving.