brake Lexus GS250 2012 Owner's Guide

2554-5. Using the driving support
4
Driving
GS350/250_EE (OM30C36E)To change the set speed, operate the lever until the desired set speed
is obtained.
Increases the speed
Decreases the speed
Fine adjustment: Momentarily
move the lever in the desired direc-
tion.
Large adjustment: Hold the lever
in the desired direction.
The set speed will be increased or decreased as follows:
Fine adjustment: By approximately 1.6 km/h (1 mph) each time the lever
is operated.
Large adjustment: The set speed can be increased or decreased continually
until the lever is released.
Pulling the lever toward you
cancels the constant speed
control.
The speed setting is also canceled
when the brakes are applied.
Pushing the lever up resumes
the constant speed control.
Resuming is available when the
vehicle speed is more than approx-
imately 40 km/h (25 mph).
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2

2624-5. Using the driving support
GS350/250_EE (OM30C36E)Pulling the lever toward you
cancels the cruise control.
The speed setting is also canceled
when the brakes are applied.
Pushing the lever up resumes
the cruise control and returns
vehicle speed to the set speed.
Resuming is available when the
vehicle speed is more than approx-
imately 40 km/h (25 mph).
Canceling and resuming the speed control
1
2

2634-5. Using the driving support
4
Driving
GS350/250_EE (OM30C36E)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
1
2

2644-5. Using the driving support
GS350/250_EE (OM30C36E)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
3
4

2704-5. Using the driving support
GS350/250_EE (OM30C36E)
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
appropriate, adjust the vehicle speed, as well as the distance between your
vehicle and vehicles 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
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 dis-
tance 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 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 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.

2724-5. Using the driving support
GS350/250_EE (OM30C36E)
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. 264) 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 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

2944-5. Using the driving support
GS350/250_EE (OM30C36E)
Lexus parking assist-sensor display
When an obstacle is detected while the rear view monitor system, is in use,
the warning indicator will appear in the top right of the screen even if the dis-
play setting has been set to off.
Sensor detection information
The sensor’s detection areas are limited to the areas around the vehicle’s
front corner and rear bumpers.
Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where
this may occur are listed below.
• There is dirt, snow or ice on the sensor. (Wiping the sensors will resolve
this problem.)
• The sensor is frozen. (Thawing the area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen may show an
abnormal display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle
engines, air brakes of large vehicles, or other loud noises producing
ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the
vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under the bumpers is not detected.
• If obstacles draw too close to the sensor.
• A non-genuine Lexus suspension (lowered suspension etc.) is installed.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there are instances in which, because of
their shape, signs and other objects may be judged by the sensor to be closer
than they are.

2964-5. Using the driving support
GS350/250_EE (OM30C36E)
CAUTION
When using the Lexus parking assist-sensor
Observe the following precautions.
Failing to do so may result in the vehicle being unable to be driven safely
and possibly cause an accident.
Do not use the sensor at speeds in excess of 10 km/h (6 mph).
The sensors’ detection areas and reaction times are limited. When moving
forward or reversing, check the areas surrounding the vehicle (especially
the sides of the vehicle) for safety, and drive slowly, using the brake to
control the vehicle’s speed.
Do not install accessories within the sensors’ detection areas.
NOTICE
When using Lexus parking assist-sensor
In the following situations, the system may not function correctly due to a
sensor malfunction etc. Have the vehicle checked by any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
The Lexus parking assist-sensor operation display flashes, and a beep
sounds when no obstacles are detected.
If the area around a sensor collides with something, or is subjected to
strong impact.
If the bumper collides with something.
If the display shows continuously without a beep.
If a display error occurs, first check the sensor.
If the error occurs even if there is no ice, snow or mud on the sensor, it is
likely that the sensor is malfunctioning.
Notes when washing the vehicle
Do not apply intensive bursts of water or steam to the sensor area.
Doing so may result in the sensor malfunctioning.

3244-5. Using the driving support
GS350/250_EE (OM30C36E)
CAUTION
When using the Lexus parking assist monitor system
When backing up, be sure to check visually behind and all around the vehi-
cle before proceeding.
Observe the following precautions to avoid an accident that could result in
death or serious injuries.
The parking assist monitor is a supplemental device intended to assist the
driver when backing up. Never depend on the parking assist monitor
entirely when backing up. Always make sure your intended path is clear.
Use caution, just as you would when backing up any vehicle.
Never back up while looking only at the screen.
The image shown on the screen may differ from the actual state, and you
could collide with another vehicle or obstacles if backing up looking only
at the screen, possibly causing an accident. When backing up, be sure to
check in front of and behind the vehicle, both directly and with mirrors.
Be sure to back up slowly, depressing the brake pedal to control vehicle
speed.
If you seem likely to hit nearby vehicles, obstacles, people or mount the
shoulder, depress the brake pedal to stop the vehicle, then disable the
assist system by select on the screen to cancel the system.
The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to
traffic conditions, road surface conditions, vehicle condition, etc. when
parking. It is necessary to be fully aware of this before using the parking
assist system.
When parking, be sure to check that the parking space will accommodate
your vehicle before maneuvering into it.
Do not use system in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or emergency tires
• When the trunk lid is not closed completely
• On roads that are not flat or straight, such as curves or slopes.

3334-5. Using the driving support
4
Driving
GS350/250_EE (OM30C36E)
Driving assist systems
ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied sud-
denly, or if the brakes are applied while driving on a slippery
road surface
Brake assist
Generates an increased level of braking force after the brake
pedal is depressed when the system detects a panic stop situation
VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces
VSC+ (Vehicle Stability Control+)
Provides cooperative control of the ABS, TRC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery
road surfaces by controlling steering performance.
TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery
roads
Hill-start assist control
P. 341
To help enhance driving safety and performance, the following
systems operate automatically in response to various driving situa-
tions. Be aware, however, that these systems are supplementary
and should not be relied upon too heavily when operating the vehi-
cle.