warning Lexus GS300h 2015 Workshop Manual

2974-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
■Warning message
Warning messages are used to indicate a system malfunction or to inform the driver of
the need for caution while driving. ( →P. 4 8 2 )
■Customization
The following settings can be changed.
For how to change settings, refer to P. 581.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering control functionTurn steering wheel assistance on and off
Vehicle sway warningTurn function on and off
Adjust alert sensitivity

2984-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
RSA (Road Sign Assist)∗
RSA recognizes specific road signs
using the camera sensor and provides
information to the driver via the multi-
information display.
If the system judges that the vehicle is being driven over the speed limit, perform-
ing prohibited actions, etc., in relation to the recognized road signs, it alerts the
driver using a warning display and warning buzzer
*.
*: This setting needs to be customized.
∗: If equipped
Summary of function
Camera sensor
WA R N I N G
■Before using the RSA
Do not rely solely upon the RSA system. RSA is a system which supports the driver by
providing information, but it is not a replacement for a driver’s own vision and aware-
ness. Drive safely by always paying careful attention to the traffic rules.
Inappropriate or negligent driving could lead to an unexpected accident.

3014-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F00E_(EE)
In the following situations, the RSA system alerts the driver using a warning dis-
play.
●When the vehicle speed exceeds the speed warning threshold applied to the
speed limit of the sign displayed on the multi-information display, the sign
color becomes inverted.
●If it is detected that your vehicle is overtaking when a no overtaking sign is dis-
played on the multi-information display, the sign flashes.
●When the RSA system recognizes a no-entry sign and detects that the vehicle
has entered a no-entry area based on the map information of the navigation
system, the no-entry sign flashes.
■Automatic turn-off of RSA sign display
One or more signs automatically turn off in the following situations.
●A new sign is not recognized for a certain distance.
●The road changes due to a left or right turn, etc.
■Conditions in which the function may not operate or detect correctly
In the following situations, RSA does not op erate normally and may not recognize signs,
display the incorrect sign, etc. However, this does not indicate a malfunction.
●The camera sensor is misaligned due to a st rong impact being applied to the sensor,
etc.
●Dirt, snow, stickers, etc., are on the windshield near the camera sensor.
●In inclement weather such as heavy rain, fog, snow or sand storms
●Light from an oncoming vehicle, the sun, etc., enters the camera sensor.
●The sign is dirty, faded, tilted or bent, and if an electronic sign, the contrast is poor.
●All or part of the sign is hidden by the leaves of a tree, a pole, etc.
●The sign is only visible to the camera sensor for a short amount of time.
●The driving scene (turning, lane change, etc.) is judged incorrectly.
●Even if it is a sign not appropriate for the currently traveled lane, such a sign exists
directly after a freeway branches, or in an adjacent lane just before merging.
●Stickers are attached to the rear of the preceding vehicle.
●A sign resembling a system compatible sign is recognized.
●The vehicle is driven in a country with a different direction of traffic.
●Side road speed signs may be detected and displayed (if positioned in sight of the cam-
era sensor) while the vehicle is traveling on the main road.
●Roundabout exit road speed signs may be detected and displayed (if positioned in sight
of the camera sensor) while traveling on a roundabout.
Warning display

3024-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
■When driving vehicle in country with different speed unit
Since RSA recognizes signs based on the set unit of the meter, it is necessary to change
the set unit of the meter. Adjust the set unit of the meter to the speed unit of signs in the
current location. (→P. 585)
■Turning the system on/off
■Speed limit sign display
If the power switch was last turned off while a speed limit sign was displayed on the multi-
information display, the same sign displays again when the power switch is turned to ON
mode.
■Customization
Setting (e.g. speeding warning threshold) can be changed.
(Customizable feature: →P. 5 8 1 )
Select on of the
multi-information display (
→P. 111)
Press on the steering wheel.
1
2

3054-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F00E_(EE)
WA R N I N G
■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 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

3104-5. Using the driving support systems
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Pulling the lever toward you cancels
the speed control.
The speed control is also canceled when
the brake pedal is depressed.
(When the vehicle has been stopped by
system control, depressing the brake
pedal 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, cruise control does not resume when
the vehicle speed is approximately 40 km/h (25 mph) or less.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehicle-
to-vehicle distance.
■Wa r n i n g s m a y n o t o c c u r w h e n
In the following instances, warnings may not occur even when the vehicle-to-
vehicle distance is small.
●When the speed of the preceding vehicle matches or exceeds your vehicle
speed
●When the preceding vehicle is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●When depressing the accelerator pedal
Canceling and resuming the speed control
1
2
Approach warning (vehicle-to- vehicle distance control mode)

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

3174-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
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

3224-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
Pulling the lever toward you cancels
the speed control.
The speed control is also canceled when
the brake pedal is depressed.
Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, cruise control does not
resume when the vehicle speed is
approximately 40 km/h (25 mph) or
less.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehicle-
to-vehicle distance.
■Wa r n i n g s m a y n o t o c c u r w h e n
In the following instances, warnings may not occur even when the vehicle-to-
vehicle distance is small.
●When the speed of the preceding vehicle matches or exceeds your vehicle
speed
●When the preceding vehicle is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●When depressing the accelerator pedal
Canceling and resuming the speed control
1
2
Approach warning (vehicle-to-vehicle distance control mode)

3244-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
■Dynamic radar cruise control 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).
■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).
●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.
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.
■Automatic cancelation of constant speed control mode
Constant speed control mode is automatica lly 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
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 )