2017 Lexus GS300h cruise control

2284-2. Driving procedures
GS450h_300h_OM_OM30F92E_(EE)
■Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
●When the vehicle comes to a stop
●If the accelerator pedal is depressed for more than a certain period of time
●When the shift lever is shifted to other than D
■Downshifting restrictions warning buzzer
To help ensure safety and driving performance, downshifting operation may sometimes
be restricted. In some circumstances, downsh ifting may not be possible even when the
shift lever or paddle shift switch is operated. (A buzzer will sound twice.)
■Snow mode automatic deactivation
Snow mode is automatically deactivated if the power switch is turned off after driving in
snow mode.
■When driving with cruise control or dynamic radar cruise control with full-speed range
activated
Even when performing the following actions with the intent of enabling engine braking,
engine braking will not activate because crui se control or dynamic radar cruise control
with full-speed range will not be canceled.
●GS450h: While driving in the D position or S mode, downshifting to 7, 6, 5 or 4. (  P. 296, 308)
●GS300h: While driving in the D position, downshifting to 5 or 4. ( P. 296, 308)
●When switching the driving mode to sport mode while driving in D position. ( P. 311)
■Restraining sudden start (Drive-Start Control)
●When the following unusual operation is performed, the engine output may be
restrained.

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4-5. Using the driving support systems
Driving
GS450h_300h_OM_OM30F92E_(EE)
Lexus Safety System+
◆PCS (Pre-Crash Safety system) 
P. 270
◆LKA (Lane-Keeping Assist) P. 282
◆AHS (Adaptive High-beam System) 
 P. 241
◆Automatic High Beam 
 P. 246
◆RSA (Road Sign Assist) P. 291
◆Dynamic radar cruise control with full-speed range P. 296
: If equipped
The Lexus Safety System+ consists of the following drive assist systems and
contributes to a safe and comfortable driving experience:
WARNING
■Lexus Safety System+
The Lexus Safety System+ is designed to operate under the assumption that the driver
will drive safely, and is designed to help reduce the impact to the occupants and the
vehicle in the case of a collision or assist the driver in normal driving conditions.
As there is a limit to the degree of reco gnition accuracy and control performance that
this system can provide, do no t overly rely on this system. The driver is always responsi-
ble for paying attention to the vehicle’s surroundings and driving safely.

2824-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
LKA (Lane-Keeping Assist) 
When driving on highways and freeways with white or yellow l
ines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering wheel to keep the vehicle in its lane. Further-
more, the system also provides steering assistance when dynamic radar cruise
control with full-speed range is operating to keep the vehicle in its lane .
The LKA system recognizes visible
white or yellow lines with the camera
sensor on the upper portion of the front
windshield.
◆Lane departure alert function
When the system determines that
the vehicle might depart from its
lane, a warning is displayed on the
multi-information display, and either
the warning buzzer sounds or the
steering wheel vibrates to alert the
driver. When the warning buzzer sounds or
the steering wheel vibrates, check
the surrounding road situation and
carefully operate the steering wheel
to move the vehicle back to the cen-
ter of the lane.
: If equipped
Summary of functions
Functions included in LKA system

2844-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
◆Lane centering function
This function is linked with radar
cruise control and provides the
required assistance by operating the
steering wheel to keep the vehicle in
its current lane.
When radar cruise control is not
operating, the lane centering func-
tion does not operate.
For Israel: If the system detects that
the steering wheel has not been
operated for a fixed amount of time
or the steering wheel is not being
firmly gripped, a warning is displayed
on the multi-information display and
the warning buzzer sounds.
Except for Israel: If the system
detects that the steering wheel has
not been operated for a fixed amount
of time or the steering wheel is not
being firmly gripped, a warning is dis-
played on the multi-information dis-
play and the function is temporarily
canceled.

2964-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
Dynamic radar cruise control with full-speed
range 
In vehicle-to-vehicle distance control mode, the vehicle automatically acceler-
ates, decelerates and stops to match the speed changes of the preceding vehicle
even if the accelerator pedal is not depr
essed. In constant speed control mode,
the vehicle runs at a fixed speed.
Use the dynamic radar cruise control with full-speed range on freeways and
highways. ● Vehicle-to-vehicle distance control mode ( P. 299)
● Constant speed control mode ( P. 304)
Vehicle-to-vehicle distance button
Display
Set speed
Indicators
Cruise control switch
: If equipped
Summary of functions
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4-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Before using dynamic radar cruise control with full-speed range
Driving safely is the sole resp onsibility of the driver. Do not rely solely on the system,
and drive safely by always paying careful attention to your surroundings.
The dynamic radar cruise control with full-speed range provides driving assistance to
reduce the driver’s burden. However, there are limitations to the assistance provided.
Even when the system is functioning norma lly, the condition of the preceding vehicle as
detected by the system may differ from the condition observed by the driver. There-
fore, the driver must always remain alert, assess the danger of each situation and drive
safely. Relying on this system or assuming the system ensures safety while driving can
lead to an accident, resulting in death or serious injury.
■Cautions regarding the driving assist systems
Observe the following precautions, as there are limitations to the assistance provided
by the system.
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-sp eed range is only intended to help the
driver in determining the fo llowing distance between the driver’s own vehicle and a
designated vehicle traveling ahead. It is no t a mechanism that allows careless or inat-
tentive driving, and it is not a system that can assist the driver in low-visibility condi-
tions. 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 fol-
lowing distance between the driver’s own vehicle and a designated vehicle traveling
ahead is within a set range. It is not capable of making any other type of judgement.
Therefore, it is absolutely necessary 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 limited capability to pre-
vent or avoid a collision with a vehicle trave ling 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.
■To avoid inadvertent dynamic radar cruise control with full-speed range activation
Switch the dynamic radar cruise control wi th full-speed range off using the “ON/OFF”
button when not in use.

2984-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■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 accident result-
ing in death or serious injury.
●Roads where there are pedestrians, cyclists, etc.
●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 sp eed when driving down a steep hill.
●At entrances to freeways and highways
●When weather conditions are bad enough that they may prevent the se nsors from
detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the fron t surface of the radar sensor or camera sen-
sor
●In traffic conditions that require frequent repeated acceleration and deceleration
●When your vehicle is towing a trailer (vehicles with towing package) or during emer-
gency towing
●When an approach warning buzzer is heard often

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Driving
GS450h_300h_OM_OM30F92E_(EE) This mode employs a radar sensor to detect the presence of vehicles up to
approximately 100 m (328 ft.) 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 dis-
tance can also be set by operating the vehicle-to-vehicle distance button.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When a vehicle is detected running ahead of you, the system automatically deceler-
ates your vehicle. When a greater reduction in vehicle speed is necessary, the system
applies the brakes (the stop lights will come on at this time). 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. Approach wa rning 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 ve hicle will also stop (vehicle is stopped by
system control). After the vehicle ahead starts off, pushing the cruise control lever up
or depressing the accelerator pedal will resume follow-up cruising.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed
The system accelerates until the set speed is reached. The system then returns to con-
stant speed cruising.
Driving in vehicl e-to-vehicle distance control mode
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