brake Lexus GS350 2017 Service Manual

3384-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(EE)
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.
■Warnings may not occur when
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)

3404-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(EE)
■Dynamic radar cruise control with full-speed range can be set when
●The shift lever is in D.
●Range 4 or higher of D has been select ed by using the paddle shift switch.
●Vehicle speed is above approximately 50 km/h (30 mph).
However, when a preceding vehicle is dete cted, 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 approximat ely 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:

341
4-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30F83E_(EE)
■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 an y authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
■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 driv ing. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( P. 524)
■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. 338) 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 (trailers with no load on board, etc.)
●Motorcycles travelin g in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor

3424-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(EE)
■Conditions under whic h 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

3464-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(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.
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
1
2
3

3504-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(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.
■Warnings may not occur when
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)

353
4-5. Using the driving support systems
4
Driving
GS350_200t_GS F_OM_OM30F83E_(EE)
■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 an y authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
■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 driv ing. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( P. 524)
■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. 338) 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 (trailers with no load on board, etc.)
●Motorcycles travelin g in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor

3544-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(EE)
■Conditions under whic h 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

3564-5. Using the driving support systems
GS350_200t_GS F_OM_OM30F83E_(EE)
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 direction.
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 spee d 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 approximately 40
km/h (25 mph).
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2

375
4
4-5. Using the driving support systems
Driving
GS350_200t_GS F_OM_OM30F83E_(EE)
Driving assist systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, 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 main-
tain directional stability when swerving on slippery road surfaces by con-
trolling 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
To help enhance driving safety and performance, the following systems oper-
ate automatically in response to various driving situations. Be aware, however,
that these systems are suppl ementary and should not be relied upon too heav-
ily when operating the vehicle.