Lexus GS300h 2015 Owner's Manual

3114-5. Using the driving support systems
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Driving
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When constant speed control mode is selected, your vehicle will maintain a set
speed without controlling the vehicle-to-vehicle distance. Select this mode only
when vehicle-to-vehicle distance control mode does not function correctly due
to a dirty radar sensor, etc.
With the cruise control off, press and
hold the “ON/OFF” button for 1.5
seconds or more.
Immediately after the “ON/OFF” but-
ton is pressed, the radar cruise control
indicator will come on. Afterwards, it
switches to the cruise control indicator.
Switching to constant speed control
mode is only possible when operating
the lever with the cruise control off.
Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (above
approximately 50 km/h [30 mph])
and push the lever down to set the
speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the
lever is released becomes the set speed.
Adjusting the speed setting: →P. 3 0 8
Canceling and resuming the speed setting: →P. 3 1 0
Selecting constant speed control mode
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3124-5. Using the driving support systems
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■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 switch.
●Vehicle speed is above approximately 50 km/h (30 mph).
However, when a preceding vehicle is detected, the dynamic radar cruise control with
full-speed range can be set even if the vehicle speed is at or below approximately
50 km/h (30 mph).
■Accelerating after setting the vehicle speed
The vehicle can accelerate by operating the accelerator pedal. After accelerating, the
set speed resumes. However, during vehicle-to-vehicle distance control mode, the vehi-
cle speed may decrease below the set speed in order to maintain the distance to the pre-
ceding vehicle.
■Automatic cancelation of vehicle-to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically canceled in the following situ-
ations.
●Actual vehicle speed falls below approximately 40 km/h (25 mph) when there are no
vehicles ahead.
●The preceding vehicle leaves the lane when your vehicle is following at a vehicle speed
below approximately 40 km/h (25 mph). Otherwise, the sensor can not properly
detect the vehicle.
●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 snow mode is set.
●The sensor cannot detect correctly because it is covered in some way.
●Pre-crash braking is activated.
●The parking brake is operated.
●The vehicle is stopped by syst em control on a steep incline.
●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 vehicle has been stopped for about 3 minutes
If vehicle-to-vehicle distance control mode is automatically canceled for any other rea-
son, there may be a malfunction in the system. Contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.

3134-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F00E_(EE)
■Automatic cancelation of constant speed control mode
Constant speed control mode is automatically canceled in the following situations:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below the set vehi-
cle speed.
●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.
●Pre-crash braking is activated.
If constant speed control mode is automatically canceled for any other reason, there may
be a malfunction in the system. Contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
■Warning messages and buzzers for dynamic radar cruise control with full-speed range
Warning messages and buzzers are used to in dicate a system malfunction or to inform
the driver of the need for caution while driv ing. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( →P. 4 8 2 )
■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the brake pedal
when deceleration of the system is insufficient or operate the accelerator pedal when
acceleration is required.
As the sensor may not be able to correctly detect these types of vehicles, the approach
warning ( →P. 310) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (traile rs with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor

3144-5. Using the driving support systems
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■Conditions under which the vehicle-to-vehicle distance control mode may not function
correctly
In the case of the following conditions, operate the brake pedal (or accelerator pedal,
depending on the situation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system may not
operate properly.
●When the vehicle ahead of you decelerates suddenly
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)
●Preceding vehicle has an extremely high
ground clearance
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

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4-5. Using the driving support systems
Driving
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Dynamic radar cruise control∗
In vehicle-to-vehicle distance control mode, the vehicle automatically acceler-
ates and decelerates to match the speed changes of the preceding vehicle even
if the accelerator pedal is not depressed. In constant speed control mode, the
vehicle runs at a fixed speed.
Use the dynamic radar cruise control on freeways and highways.
●Vehicle-to-vehicle distance control mode (
→P. 3 1 8 )
●Constant speed control mode ( →P. 323)
Vehicle-to-vehicle distance button
Display
Set speed
Indicators
Cruise control switch
∗: If equipped
Summary of functions
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3164-5. Using the driving support systems
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WA R N I N G
■Before using dynamic radar cruise control
Driving safely is the sole responsibility of the driver. Do not rely solely on the system,
and drive safely by always paying ca reful attention to your surroundings.
The dynamic radar cruise control 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, as sess 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 is only in tended 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 mechanism 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 determines whether the following 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 has limited 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.
■To avoid inadvertent dynamic radar cruise control activation
Switch the dynamic radar cruise control off using the “ON/OFF” button when not in
use.

3174-5. Using the driving support systems
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Driving
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WA R N I N G
■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 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 speed when driving down a steep hill.
●At entrances to freeways and highways
●When weather conditions are bad enough that they may prevent the sensors from
detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
●When there is rain, snow, etc. on the front 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 or during emergency towing
●When an approach warning buzzer is heard often

3184-5. Using the driving support systems
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This mode employs a radar sensor to detect the presence of vehicles up to
approximately 120 m (400 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 ve hicle from closing in on the vehicle ahead.
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 vehicle-to-vehicle distance control mode
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3194-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
Press the “ON/OFF” button to acti-
vate the cruise control.
Radar cruise control indicator will come
on and a message will be displayed on
the multi-information display.
Press the button again to deactivate the
cruise control.
If the “ON/OFF” button is pressed and
held for 1.5 seconds or more, the system
turns on in constant speed control
mode. (→P. 323)
Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (above
approximately 50 km/h [30 mph])
and push the lever down to set the
speed.
Cruise control “SET” indicator will come
on.
The vehicle speed at the moment the
lever is released becomes the set speed.
Setting the vehicle speed (vehicle-t o-vehicle distance control mode)
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3204-5. Using the driving support systems
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To change the set speed, operate the lever until the desired set speed is dis-
played.Increases the speed
Decreases the speed
Fine adjustment: Momentarily move
the lever in the desired direction.
Large adjustment: Hold the lever up or
down to change the speed, and release
when the desired speed is reached.
In the vehicle-to-vehicle distance control mode, the set speed will be increased
or decreased as follows:
XFor Europe
Fine adjustment: By 5 km/h (3.1 mph)
*1 or 5 mph (8 km/h)*2 each time the lever is
operated
Large adjustment: Increases or decreases in 5 km/h (3.1 mph)
*1 or 5 mph (8 km/h)*2
increments for as long as the lever is held
XExcept for Europe
Fine adjustment: By 1 km/h (0.6 mph)
*1 or 1 mph (1.6 km/h)*2 each time the lever is
operated
Large adjustment: Increases or decreases in 5 km/h (3.1 mph)
*1 or 5 mph (8 km/h)*2
increments for as long as the lever is held
In the constant speed control mode ( →P. 323), the set speed will be increased
or decreased as follows:
Fine adjustment: By 1 km/h (0.6 mph)*1 or 1 mph (1.6 km/h)*2 each time the lever is
operated
Large adjustment: The speed will continue to change while the lever is held.
*1: When the set speed is shown in “km/h”
*2: When the set speed is shown in “MPH”
Adjusting the set speed
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