Page 10 of 69

GS350_OM_OM30F69U_(U)
2234-5. Using the driving support systems
4
Driving
This mode employs a radar sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead, determines the current vehicle-to-
vehicle following distance, and operates to maintain a suitable following
distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long downhill
slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle
distance can also be set by operating the vehicle-to-vehicle distance control.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically decel-
erates your vehicle. When a greater reduction in vehicle speed is necessary, the
system applies the brakes. A warning tone warns you when the system cannot
decelerate sufficiently to prevent your vehicle from closing in on the vehicle
ahead.
Driving in vehicle-to-vehicle distance control mode
1
2
Page 13 of 69

226
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
■Dynamic radar cruise control can be set when
●The shift lever is in D.
●Range 4 or higher of D has been selected by using the paddle shift.
●Vehicle speed is above approximately 30 mph (50 km/h).
■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 distance 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 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.
●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
the AUTO mode or the high speed wiper operation).
●When snow mode is set.
If vehicle-to-vehicle distance control driving is automatically canceled for any other
reason, there may be a malfunction in the system. Contact your Lexus dealer.
Page 14 of 69

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
Page 17 of 69
230
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
CAUTION
■To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON/OFF” button when not in use.
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident
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 sensors
from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
●During emergency towing
Page 18 of 69

GS350_OM_OM30F69U_(U)
2314-5. Using the driving support systems
4
Driving
CAUTION
■When the 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. 224) 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 sensor 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 function-
ing of the 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
Page 19 of 69
232
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
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 malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by a Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding
area.
●Do not modify or paint the sensor and grille cover.
●If the radar sensor needs to be replaced, contact your Lexus dealer.
Page 20 of 69
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
Page 21 of 69

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