2017 Lexus GS300h TRC

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4-5. Using the driving support systems
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Driving
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■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 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:

3064-5. Using the driving support systems
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■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 travelin g in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor

3104-5. Using the driving support systems
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■Automatic cruise control cancelation
Cruise control will stop maintaining the vehicl e speed in any of the following situations.
●Actual vehicle speed falls more than approximately 16 km/h (10 mph) below the preset
vehicle speed.
At this time, the memorized set speed is not retained.
●Actual vehicle speed is 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.
■If the warning message for the cruise control is shown on the multi-information display
Press the “ON/OFF” button once to deactivate the system, and then press the button
again to reactivate the system.
If the cruise control speed cannot be set or if the cruise control cancels immediately after
being activated, there may be a malfunction in the cruise control system. Have the vehi-
cle inspected by any authorized Lexus retaile r or Lexus authorized repairer, or any reli-
able repairer.
WARNING
■To avoid operating the cruise control by mistake
Switch the cruise control off using the “ON/OFF” button when not in use.
■Situations unsuitable for cruise control
Do not use cruise control in any of the following situations.
Doing so may result in loss of control and could cause an accident resulting in death or
serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those covered with rain, ice or snow
●On steep hills
Vehicle speed may exceed the set sp eed when driving down a steep hill.
●When your vehicle is towing a trailer or during emergency towing

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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.

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◆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

3264-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE) The slip indicator light will flash while
the TRC/VSC/ABS systems are oper-
ating.
If the vehicle gets stuck in mud, dirt
or snow, the TRC system may reduce power
from the hybrid system to the wheels. Pressing to turn the system off may
make it easier for rock the vehicle in order to free it.
To turn the TRC system off, quickly
press and release . The “Traction Control Turned Off” will
be shown on the multi-information dis-play.
Press again to turn the system back
on.
When the TRC/VSC/ABS sy stems are operating
Disabling the TRC system

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■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 mult i-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
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■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 steering
wheel 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.