brakes Lexus GS350 2015 Using the driving support systems

GS350_OM_OM30F69U_(U)
2154-5. Using the driving support systems
4
Driving
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 mph (1.6 km/h) each time the lever is oper-
ated.
Large adjustment: The set speed can be increased or decreased continually until
the lever is released.
Pulling the lever toward you can-
cels 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 vehi-
cle speed is more than approximately
25 mph (40 km/h).
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2

222
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
Pulling the lever toward you can-
cels 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 vehi-
cle speed is more than approximately
25 mph (40 km/h).
Canceling and resuming the speed control
1
2

GS350_OM_OM30F69U_(U)
2234-5. Using the driving support systems
4
Driving
This mode employs a radar sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) 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 distance 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 decel-
erates your vehicle. When a greater reduction in vehicle speed is necessary, 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

224
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
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 auto-
matic 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. Apply the brakes to ensure an appropriate vehicle-to-vehicle dis-
tance.
■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 vehi-
cle 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

GS350_OM_OM30F69U_(U)
2294-5. Using the driving support systems
4
Driving
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 appropri-
ate, adjust the vehicle speed, as well as the distance between your vehicle and vehi-
cles 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 determin-
ing 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
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 deter-
mine 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.

GS350_OM_OM30F69U_(U)
2314-5. Using the driving support systems
4
Driving
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. 224) 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 sensor 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 function-
ing 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

248
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
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
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road
surfaces by controlling steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spin-
ning when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
P. 2 5 6
◆VGRS (Variable Gear Ratio Steering) (if equipped)
Adjusts the front wheel turning angle in accordance with the vehicle
speed and steering wheel movement
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be
aware, however, that these systems are supplementary and should not
be relied upon too heavily when operating the vehicle.

GS350_OM_OM30F69U_(U)
2494-5. Using the driving support systems
4
Driving
◆DRS (Dynamic Rear Steering) (if equipped)
Contributes to the turning characteristics and responsiveness of the
vehicle by slightly adjusting the rear wheel angle of the vehicle in accor-
dance with steering wheel movement
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆AVS (Adaptive Variable Suspension system) (if equipped)
By independently controlling the damping force of the shock absorbers
for each of the 4 wheels according to the road and driving conditions,
this system helps riding comfort with superior steering stability, and
helps good vehicle posture
When SPORT S+ mode is selected by the driving mode select switch,
the damping force is suitable for sporty driving (P. 245)
◆LDH (Lexus Dynamic Handling system) (if equipped)
Provides independent control of the VGRS, DRS and EPS. Contributes
to turning characteristics at low speeds, responsiveness at medium
speeds and safety at high speeds by controlling the steering angle of
the front and rear wheels in accordance with the steering wheel opera-
tion and vehicle speed
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-
start assist control, EPS, VGRS (if equipped) and DRS (if equipped)
systems
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes, engine output, steering assist, and
steering ratio and rear wheel angle
◆PCS (Pre-Collision System) (if equipped)
P. 2 5 8

256
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
Hill-start assist control
To engage hill-start assist control,
further depress the brake pedal
when the vehicle is stopped com-
pletely.
A buzzer will sound once to indicate
the system is activated. The slip indica-
tor will also start flashing.
■Hill-start assist control operating conditions
●The system operates in the following situations:
• The shift lever is in a position other than P.
• The parking brake is not applied.
• The accelerator pedal is not depressed.
●Hill-start assist control cannot be operated while the slip indicator light is illumi-
nated.
■Hill-start assist control
●While hill-start assist control is operating, the brakes remain automatically applied
after the driver releases the brake pedal. The stop lights and the high mounted
stoplight turn on.
●Hill-start assist control operates for about 2 seconds after the brake pedal is
released.
●If the slip indicator does not flash and the buzzer does not sound when the brake
pedal is further depressed, slightly reduce the pressure on the brake pedal (do not
allow the vehicle to roll backward) and then firmly depress it again. If the system still
does not operate, check that the operating conditions explained above have been
met.
Assists with starting off and temporarily maintains braking power even
if the foot is removed from the brake pedal when starting off on an
incline or a slippery slope.

258
GS350_OM_OM30F69U_(U)
4-5. Using the driving support systems
PCS (Pre-Collision System)
◆Pre-collision seat belts (front seat only)
If the pre-collision sensor detects that a collision is unavoidable, the
pre-collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or
loses control of the vehicle. (P. 32)
◆Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
◆Pre-collision braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automati-
cally applied to reduce the collision speed.

: If equipped
When the radar sensor detects possibility of a frontal collision, the pre-
collision system such as the brakes and seat belts are automatically
engaged to lessen impact as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by oper-
ating the switch. (P. 2 6 0 )