warning Lexus GS300h 2013 Owner's Guide

2744-2. Driving procedures
GS450h_300h_OM_OM30D53E_(EE)
When the parking brake is set automatically while the system is holding the
brakes
The parking brake will not be released automatically. Release the parking
brake by operating the parking brake switch, making sure that the parking
brake indicator light goes off. (P. 269)
When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. (P. 832, 843)
CAUTION
When the vehicle is on a steep incline
When using the brake hold system on a steep incline exercise caution. The
brake hold function may not hold the vehicle in such a situation.
When stopped on a slippery road
The system cannot stop the vehicle when the gripping ability of the tires
has been exceeded. Do not use the system when stopped on a slippery road.
NOTICE
When parking the vehicle
The brake hold system is not designed for use when parking the vehicle for
a long period of time. Turning the power switch off while the system is
holding the brake may release the brake, which would cause the vehicle to
move. When operating the power switch, depress the brake pedal, set the
parking brake and shift the shift lever to P.

3004-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
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.
Vehicle speed is above approximately 40 km/h (25 mph).
Accelerating after setting the vehicle speed
The vehicle can be accelerated normally. After acceleration, the set speed
resumes.
Even without canceling the cruise control, the set speed can be increased by
first accelerating the vehicle to the desired speed and then pushing the lever
down to set the new speed.
Automatic cruise control cancelation
Cruise control will stop maintaining the vehicle speed in any of the following
situations.
Actual vehicle speed falls more than approximately 16 km/h (10 mph)
below the preset vehicle speed.
At this time, the memorized set speed is not retained.
Actual vehicle speed is 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.
If the warning message for the cruise control is shown on the multi-informa-
tion display
Press the “ON/OFF” button once to deactivate the system, and then press the
button again to reactivate the system.
If the cruise control speed cannot be set or if the cruise control cancels imme-
diately after being activated, there may be a malfunction in the cruise control
system. Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.

3074-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 distance can also be set by operating the vehicle-to-vehicle dis-
tance 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
decelerates your vehicle. When a greater reduction in vehicle speed is nec-
essary, 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
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3084-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
Example of follow-up cruising
When following a vehicle driving slower than the set speed
The system continues follow-up cruising while adjusting for changes in
the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle
distance set by the driver.
Example of acceleration
When there are no longer any vehicles ahead driving slower than
the set speed
The system accelerates until the set speed is reached. The system then
returns to constant speed cruising.
When your vehicle is too close to a vehicle ahead, and sufficient
automatic deceleration via the cruise control is not possible, the dis-
play 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. Apply the brakes to ensure an appro-
priate vehicle-to-vehicle distance.
Warnings may not occur when
In the following instances, there is a possibility that the warnings
will not occur:
When the speed of the vehicle ahead matches or exceeds your
vehicle speed
When the vehicle ahead is traveling at an extremely slow
speed
Immediately after the cruise control speed was set
At the instant the accelerator is applied
Approach warning
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3124-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
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 16 km/h (10 mph) below
the set vehicle speed.
At this time, the memorized set speed is not retained.
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 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. 841) Grille cover
Radar sensor
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3164-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
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 acci-
dent 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 sen-
sors from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
When an approach warning buzzer is heard often
When your vehicle is towing a trailer or during emergency towing

3174-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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. 308) 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 sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
When water or snow thrown up by a the surrounding vehicles hinders the
functioning 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

3254-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 distance can also be set by operating the vehicle-to-vehicle dis-
tance 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
decelerates your vehicle. When a greater reduction in vehicle speed is nec-
essary, 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-vehi-
cle 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
Driving in vehicle-to-vehicle distance control mode
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3264-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)lever up or depressing the accelerator pedal will resume follow-up cruis-
ing.
Example of acceleration
When there are no longer any vehicles ahead driving slower than
the set speed
The system accelerates until the set speed is reached. The system then
returns to constant speed cruising.
When your vehicle is too close to a vehicle ahead, and sufficient
automatic deceleration via the cruise control is not possible, the dis-
play 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. Apply the brakes to ensure an appro-
priate vehicle-to-vehicle distance.
Warnings may not occur when
In the following instances, there is a possibility that the warnings
will not occur:
When the speed of the vehicle ahead matches or exceeds your
vehicle speed
When the vehicle ahead is traveling at an extremely slow
speed
Immediately after the cruise control speed was set
At the instant the accelerator is applied
Approach warning
3

3314-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 16 km/h (10 mph) below
the set vehicle speed.
At this time, the memorized set speed is not retained.
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 the LKA (Lane-Keeping Assist) will be activated
Using the radar cruise control in vehicle-to-vehicle distance control mode,
lane keeping assistance control 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 or plastic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control with full-speed range is canceled if an obstruc-
tion is detected.
Warning messages and buzzers for dynamic radar cruise control with full-
speed range
Warning messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. (P. 841) Grille cover
Radar sensor
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