2016 Lexus GS450h brake

GS450h_OM_OM30E99U_(U)
2314-5. Using the driving support systems
4
Driving
■If the PCS warning light flashes and a warning message is displayed on the multi-infor-
mation display
The pre-collision system may be temporarily unavailable or there may be a malfunction
in the system.
●In the following situations, the warning light will turn off, the message will disappear and
the system will become operational when normal operating conditions return:
• When the radar sensor or camera sensor or the area around either sensor is hot, such as in the sun
• When the radar sensor or camera sensor or the area around either sensor is cold,
such as in an extremely cold environment
• When the radar sensor or front grille embl em is dirty or covered with snow, etc.
• If the camera sensor is obst ructed, such as when the hood is open or a sticker is
attached to the windshield near the camera sensor
●If the PCS warning light continues to flash or the warning message does not disappear,
the system may be malfunctioning. Have the vehicle inspected by your Lexus dealer
immediately.
■If VSC is disabled
●If VSC is disabled ( P. 269), the pre-collision brake assist and pre-collision braking
functions are also disabled.
●The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake System
Unavailable” will be displayed on the multi-information display.

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4-5. Using the driving support systems
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 dis-
tance can also be set by operating th e 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 ve hicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your ve hicle will also stop (vehicle is stopped by
system control). After the vehicle ahead starts off, pushing the cruise control lever up
or depressing the accelerator peda l will resume follow-up cruising.
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 vehicle-to-vehicle distance control mode
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2
3

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GS450h_OM_OM30E99U_(U)
4-5. Using the driving support systems
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 25 mph (40 km/h) 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)

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GS450h_OM_OM30E99U_(U)
4-5. Using the driving support systems
■Dynamic radar cruise control with full-speed range 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 select ed by using the paddle shift switch.
●Vehicle speed is above approximately 30 mph (50 km/h).
However, when a preceding vehicle is detected, the dynamic radar cruise control with
full-speed range can be set even if the vehicle speed is at or below approximately
30 mph (50 km/h).
■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 25 mph (40 km/h) when there are no
vehicles ahead.
●The preceding vehicle leaves the lane when your vehicle is following at a vehicle speed
below approximately 25 mph (40 km/h). Otherwise, the sensor can not properly
detect the vehicle.
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC 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-collision braking is activated.
●The parking brake is operated.
●The vehicle is stopped by system control on a steep incline.
●The following are detected when the vehicle has been stopped by system control:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes
If vehicle-to-vehicle distance control mode is automatically canceled for any other rea-
son, there may be a malfunction in the system. Contact your Lexus dealer.

GS450h_OM_OM30E99U_(U)
2514-5. Using the driving support systems
4
Driving
■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 10 mph (16 km/h) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is turned off by pressing the VSC OFF switch.
●Pre-collision braking is activated.
If constant speed control mode is automatica lly canceled for any other reason, there may
be a malfunction in the system. Contact your Lexus dealer.
■Warning messages and buzzers for dynamic ra dar 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. If a warning message is shown on the
multi-information display, read the message and follow the instructions. ( P. 4 0 6 )
■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 insuff icient 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. 248) 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
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)

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4-5. Using the driving support systems
■Conditions under which the vehicle-to-vehicle distance control mode may not function
correctly
In the case of the following conditions, op erate the brake pedal (or accelerator pedal,
depending on the situ ation) 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
●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

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4-5. Using the driving support systems
To change the set speed, operate the lever until the desired set speed is obtained.Increases the speed
Decreases the speed
Fine adjustment: Mo mentarily move the
lever in the desired direction.
Large adjustment: Hold the lever in the
desired direction.
The set speed will be increase d or decreased as follows:
Fine adjustment: By approximately 1 mph (1.6 km/h) each time the lever is operated.
Large adjustment: The set speed can be incr eased 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 25
mph (40 km/h).
■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 se lected by using the paddle shift.
●Vehicle speed is above approximately 25 mph (40 km/h).
■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 accel-
erating the vehicle to the desired speed and then pushing the lever down to set the new
speed.
Adjusting the set speed
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2
Canceling and resuming the constant speed control
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2

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4-5. Using the driving support systems
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corresponding
to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if the
brakes are applied while drivin g 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) (if equipped)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆TRAC (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 supplementary and should not be relied upon too
heavily when operating the vehicle.