2013 Lexus GS300h Owner's Manual

3344-5. Using the driving support system
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CAUTION
Before using dynamic radar cruise control with full-speed range
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set vehicle speed. If automatic deceleration/acceleration is
not appropriate, adjust the vehicle speed, as well as the distance between
your vehicle and vehicles ahead by applying the brakes etc.
Cautions regarding the driving assist systems
Observe the following precautions.
Failure to do so may cause an accident resulting in death or serious injury.
Assisting the driver to measure following distance
The dynamic radar cruise control with full-speed range is only intended to
help the driver in determining the following distance between the driver’s
own vehicle and a designated vehicle traveling ahead. It is not a mecha-
nism that allows careless or inattentive driving, and it is not a system that
can assist the driver in low-visibility conditions. It is still necessary for
driver to pay close attention to the vehicle’s surroundings.
Assisting the driver to judge proper following distance
The dynamic radar cruise control with full-speed range determines
whether the following distance between the driver’s own vehicle and a
designated vehicle traveling ahead is appropriate or not. It is not capable
of making any other type of judgement. Therefore, it is absolutely neces-
sary for the driver to remain vigilant and to determine whether or not there
is a possibility of danger in any given situation.
Assisting the driver to operate the vehicle
The dynamic radar cruise control with full-speed range has no capability
to prevent or avoid a collision with a vehicle traveling ahead. Therefore, if
there is ever any danger, the driver must take immediate and direct control
of the vehicle and act appropriately in order to ensure the safety of all
involved.

335
4 4-5. Using the driving support system
Driving
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
To avoid inadvertent dynamic radar cruise control with full-speed range
activation
Switch the cruise control off using the “ON/OFF” button when not in use.
Situations unsuitable for dynamic radar cruise control with full-speed range
Do not use dynamic radar cruise control with full-speed range in any of the
following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
In heavy traffic
On roads with sharp bends
On winding roads
On slippery roads, such as those covered with rain, ice or snow
On steep downhills, or where there are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
At entrances to expressways
When weather conditions are bad enough that they may prevent the sen-
sors from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
When an approach warning buzzer is heard often
When your vehicle is towing a trailer or during emergency towing

3364-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
When the radar sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles
are in front of you.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (P. 308) will not be activated, and a fatal or serious
accident may result.
Vehicles that cut in suddenly
Vehicles traveling at low speeds
Vehicles that are not moving
Vehicles with small rear ends (trailers with no load on board etc.)
Motorcycles traveling in the same lane
Conditions under which the vehicle-to-vehicle distance control may not
function correctly
Apply the brakes as necessary in the following conditions as the radar sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
When water or snow thrown up by the surrounding vehicles hinders the
functioning of the radar sensor
When your vehicle is pointing upwards (caused by a heavy load in the
trunk etc.)
When the road curves or when the lanes are narrow
When steering wheel operation or your position in the lane is unstable
When the vehicle ahead of you decelerates suddenly

3374-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
Handling the radar sensor
Observe the following to ensure the cruise control system can function
effectively.
Otherwise, the system may not function correctly and could result in an
accident.
Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or
damage them.
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunc-
tion. If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
Do not disassemble the sensor.
Do not attach accessories or stickers to the sensor, grille cover or sur-
rounding area.
Do not modify or paint the sensor and grille cover.
Do not replace them with non-genuine parts.

3384-5. Using the driving support system
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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
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Driving
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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
1
2

3404-5. Using the driving support system
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Press the “LKA” switch to acti-
vate the system.
“LKA” indicator will come on.
Press the switch again to turn the
LKA system off.
The LKA system will revert to off
each time the power switch is
turned to ON mode.
Turning the LKA system on

3414-5. Using the driving support system
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Driving
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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