brake LEXUS GS300H 2019 Workshop Manual

3054-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■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 selected 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 approximately50 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:
• 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 syst em. Contact any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer.

3064-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(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. 466)
■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. 303) 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 traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of the sensor

3074-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Conditions under which 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 notoperate 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 highground clearance
●When the road curves or when the lanes arenarrow
●When steering wheel operation or your posi-tion in the lane is unstable

3094-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(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).
■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 accel- erating the vehicle to the desired speed and then pushing the lever down to set the newspeed.
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2

3244-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
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 br akes 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
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆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 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.

3254-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F92E_(EE)
◆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 accordance with
steering wheel movement
◆Hill-start assist control
Helps to prevent the vehicle from rolling backward when starting on an
incline.
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
◆AVS (Adaptive Variable Susp ension system) (if equipped)
By independently controlling the damp ing force of the shock absorbers for
each of the 4 wheels according to the road and driving conditions, this system
helps riding comfort with a high level of stability, and helps good vehicle pos-
ture
When SPORT S+ mode is selected by the driving mode select switch, the
damping force is suitable for sporty driving ( P. 312)
◆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 operation and vehicle speed
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRC, VSC, hill-start
assist control, EPS, VGRS (if equipped) and DRS (if equipped) systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes, hybrid system output, steering assist, steering ratio and
rear wheel angle
◆Emergency brake signal
When the brakes are applie d suddenly, the stop lights automatically flash to
alert the vehicle behind

3274-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Turning off both TRC and VSC systems
To turn the TRC and VSC systems off, press and hold for more than 3 seconds while the vehicle is stopped.
The VSC OFF indicator light will come on an d the “Traction Control Turned Off” will
be shown on the multi-information display.*
Press again to turn the systems back on.
*: On vehicles with PCS (Pre-Crash Safety system), pre-crash brake assist and pre-
crash braking will also be disabled. The PCS (Pre-Crash Safety system) warning
light will come on and a message will be di splayed on the multi-information display.
( P. 466)
■When the message is displayed on the multi-information display showing that TRC has
been disabled even if has not been pressed
TRC and hill-start assist control cannot be operated. Contact any authorized Lexus
retailer or Lexus authorized repa irer, or any reliable repairer.
■VGRS is disabled when
VGRS may stop operating in the following situations.
In this event, the steering wheel may move fr om its straight forward position, but it will return when the system restarts.
●The steering wheel is operated for an extended period of time while the vehicle is
stopped or is moving very slowly.
●When force is continuously applied for a long time with the steering wheel turned as far as it will go.
The center position of the steering wheel may change when VGRS is disabled. How- ever, the position will return to normal after VGRS is reactivated.
■When the 12-volt battery is disconnected
The steering wheel may move from its straight forward position, but this will be corrected automatically when driving.

3284-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
■Sounds and vibrations caused by the ABS, brake assist, VSC, Hill-start assist control, TRC and VGRS systems
Any of the following conditions may occur when the above systems are operating. None
of these indicates that a malfunction has occurred.
●Vibrations may be felt through the vehicle body and steering.
●A motor sound may be heard after the vehicle comes to a stop.
■ECB operation sound
ECB operating sound may be heard in the follow ing cases, but it does not indicate that a malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper-ated.
●Motor sounds of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes passed after the stop of the hybrid system.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard. This does not indicate a malfunction.
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled in the following situations:
●When the power switch is turned off
●If only the TRC system is turned off, the TR C will turn on when vehicle speed increases If both TRC and VSC systems are turned off, automatic re-enabling will not occur when
vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating when there is frequent steering input over an extended period of time. The steeringwheel may feel heavy as a result. Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor- mal within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate;
●The shift lever is in a position other than N or P (when starting off forward/backward on an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.

3294-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Automatic system cancelation of hill-start assist control
The hill-start assist control will be canc eled in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.
■Operating conditions of emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the vehi- cle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn of f in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking operation.
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road surfaces, even if the TRC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.

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4-6. Driving tips
Driving
GS450h_300h_OM_OM30F92E_(EE)
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generate d more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. ( P. 311)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid System
Indicator within Eco area. ( P. 108, 123)
◆Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, when using the air conditioning system,
etc., the hybrid battery (traction battery) power is consumed.
◆Accelerator pedal/brake pedal operation
●Drive your vehicle smoothly. Avoid abrupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) without having to use gasoline engine
power.
●Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) power, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly
released.
◆When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.
For economical and ecological driving, pay attention to the following points: