2015 Lexus GS450h cruise control

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4-5. Using the driving support systems
■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 ob structions, such as snow, ice and plastic
objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is cance led 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. 5 1 5 )
Grille cover
Radar sensor
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4-5. Using the driving support systems
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set speed. If automatic deceleration/acceleration is not appropri-
ate, adjust the vehicle speed, as well as the distance between your vehicle and vehi-
cles 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 is only intended to help the driver in determin-
ing the following distance between the driver’s own vehicle and a designated
vehicle traveling ahead. It is not a mechanism that allows careless or inattentive
driving, and it is not a system that can assi st 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 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 necessary for the driver to remain vigilant and to deter-
mine 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 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.

GS450h_OM_OM30F70U_(U)
2514-5. Using the driving support systems
4
Driving
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 sp eed 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

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2534-5. Using the driving support systems
4
Driving
CAUTION
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function co rrectly 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 surr ounding 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 th e sensor and grille cover.
●If the radar sensor needs to be replaced, contact your Lexus dealer.

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4-5. Using the driving support systems
Dynamic radar cruise control with full-speed
range

Dynamic radar cruise control with full-speed range supplements conven-
tional cruise control with a vehicle-to-vehicle distance control. In vehicle-
to-vehicle distance control mode, th e vehicle automatically accelerates,
decelerates or stops in order to ma intain a set following distance from
vehicles ahead. See cautions on P. 266
Vehicle-to-vehicle distance but-
ton
Display
Set speed
Indicators
Cruise control switch

: If equipped
Summary of functions
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2554-5. Using the driving support systems
4
Driving
Press the “ON/OFF” button to
activate the cruise control.
Radar cruise control indicator will
come on.
Press the button again to deactivate
the cruise control.
Accelerate or decelerate the
vehicle to the desired speed, and
push the lever down to set the
speed.
“SET” indicator will be displayed.
The vehicle speed at the moment the
lever is released becomes the set
speed.
While the vehicle is in vehicle-to-vehi-
cle distance control mode, if the lever
is released when vehicle speed is less
than 30 mph (50 km/h) and a vehicle
ahead can be detected, the vehicle
will start following the vehicle ahead at
a set speed of 30 mph (50 km/h).
Setting the vehicle speed (vehicle-to-vehicle distance control
mode)
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2594-5. Using the driving support systems
4
Driving
Pulling the lever toward you can-
cels the cruise control.
The setting is also canceled when the
brake pedal is depressed while driv-
ing.
(When the vehicle has been stopped
by system control, applying the brakes
does not cancel the setting.)
Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, when a vehicle ahead is not
detected in vehicle-to-vehicle dis-
tance control mode, cruise control
does not resume when the actual vehi-
cle speed is approximately 25 mph
(40 km/h) or less. Also, when the
vehicle is in constant speed control
mode and the actual vehicle speed is
approximately 25 mph (40 km/h) or
less, cruise control does not resume as
the set speed is cleared.
Canceling and resuming the speed control
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4-5. Using the driving support systems
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 opera tes 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 and follow-up 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. The system will respond to changes in the speed of the
vehicle ahead in order to maintain the vehicle-to-vehicle distance set by the
driver. A warning tone warns you when the system cannot decelerate sufficiently
to prevent your vehicle from closing in on the vehicle ahead. When the vehicle
ahead of you stops, your vehicle will also stop. After the vehicle ahead starts off,
pushing the cruise control lever up or depressing the accelerator pedal will
resume follow-up cruising.
Driving in vehicle-to-vehicle distance control mode
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