steering Lexus GS300h 2015 Repair Manual

2954-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
●Ve h i c l e s w a y w a r n i n g
This function operates when all of the following conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “On”.
( → P. 111)
• Vehicle speed is approximately 50 km/h (32 mph) or more.
• Width of traffic lane is approximately 3 m (9.8 ft.) or more.
• No system malfunctions are detected. ( →P. 2 9 7 )
■Temporary cancellation of functions
When operation conditions are no longer met, a function may be temporarily canceled.
However, when the operation conditions are met again, operation of the function is auto-
matically restored. ( →P. 2 9 4 )
■Steering control function
Depending on the vehicle speed, lane departure situation, road conditions, etc., the
operation of the functions may not be reco gnized or the functions may not operate.
■Lane departure alert function
The warning buzzer may be difficult to hear due to external noise, audio playback, etc.
Also, it may be difficult to feel steering wheel vibrations due to the road conditions, etc.
■Hands off steering wheel alert
Except for Israel: When the system determines that the driver has removed their hands
from the steering wheel while the steering co ntrol function is operating, a warning mes-
sage is displayed on the multi-information display.
If the driver continues to keep their hands off of the steering wheel, the buzzer sounds, a
warning message is displayed and the function is temporarily canceled. This alert also
operates in the same way when the vehicle is driven with the steering wheel lightly
gripped. However, depending on the road conditions, etc., the function may not cancel.
For Israel: When the system determines that the driver has removed their hands from the
steering wheel while the lane departure control function or lane centering function is
operating, a warning message is displayed on the multi-information display and the
buzzer sounds.
■White (yellow) lines are only on one side of road
The LDA system will not operate for the side on which white (yellow) lines could not be
recognized.

2974-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F00E_(EE)
■Warning message
Warning messages are used to indicate a system malfunction or to inform the driver of
the need for caution while driving. ( →P. 4 8 2 )
■Customization
The following settings can be changed.
For how to change settings, refer to P. 581.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering control functionTurn steering wheel assistance on and off
Vehicle sway warningTurn function on and off
Adjust alert sensitivity

3024-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
■When driving vehicle in country with different speed unit
Since RSA recognizes signs based on the set unit of the meter, it is necessary to change
the set unit of the meter. Adjust the set unit of the meter to the speed unit of signs in the
current location. (→P. 585)
■Turning the system on/off
■Speed limit sign display
If the power switch was last turned off while a speed limit sign was displayed on the multi-
information display, the same sign displays again when the power switch is turned to ON
mode.
■Customization
Setting (e.g. speeding warning threshold) can be changed.
(Customizable feature: →P. 5 8 1 )
Select on of the
multi-information display (
→P. 111)
Press on the steering wheel.
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3144-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(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 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

3264-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(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 not
operate properly.
●When the vehicle ahead of you decelerates suddenly
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

3304-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
Driving mode select switch
XVehicles without Adaptive Variable Suspension system
Normal mode
For normal driving.
Press the switch to change the driving mode to normal mode when Eco drive mode or
sport mode is selected.
Eco drive mode
Use Eco drive mode to help achieve low fuel consumption during trips that
involve frequent accelerating.
When not in Eco drive mode and the driving mo de select switch is turned to the left,
the “ECO” or “ECO MODE” indicator come s on in the multi-information display.
Sport mode
Assists acceleration response by controlling the hybrid system and steering.
Suitable for when precise handling is desirable, for example when driving on
mountain roads.
When not in Sport mode and the driving mode select switch is turned to the right, the
“SPORT” indicator comes on in the multi-information display, and the Hybrid System
Indicator changes to the tachometer. ( →P. 1 0 9 )
The driving modes can be select ed to suit driving condition.
Except
F SPORT modelsF SPORT models
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3324-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
Sport mode•SPORT S mode
Assists acceleration response by controlling the transmission and engine.
When not in SPORT S mode an d the driving mode select switch is turned to the
right, the “SPORT S” indicator comes on in the multi-information display, and the
Hybrid System Indicator changes to the tachometer. ( →P. 1 0 9 )
•SPORT S+ mode
Helps to ensure steering performance and driving stability by simulta-
neously controlling the steering and suspension in addition to the hybrid
system. Suitable for sporty driving.
When in SPORT S mode and the driving mode select switch is turned to the right,
the “SPORT S+” indicator comes on in the multi-information display.
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air condi-
tioning system to enhance fuel efficiency ( →P. 366). To improve air conditioning perfor-
mance, adjust the fan speed or turn off Eco drive mode.
■Automatic operation of the seat heater during Eco drive mode
Eco drive mode controls the heating operation and fan speed of the air conditioning sys-
tem to enhance fuel efficiency. If the driving mode select switch is switched to Eco drive
mode in cold temperatures, the seat heater will be automatically operated to assist heat-
ing performance.
■Automatic deactivation of sport mode and customized mode
If the power switch is turned off after driv ing in sport mode or customized mode, the
drive mode will be changed to normal mode.
■Driving mode pop-up display (12.3-inch display only)
When the driving mode is changed, the selected driving mode will be temporarily dis-
played on the side display. ( →P. 3 6 4 )
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3444-5. Using the driving support systems
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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 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
◆TRC (Traction Control)
Helps to maintain drive power and pr event 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 supplementary and should not be relied upon too
heavily when operating the vehicle.

3454-5. Using the driving support systems
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Driving
GS450h_300h_OM_OM30F00E_(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 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. 3 3 1 )
◆LDH (Lexus Dynamic Handling system) (if equipped)
Provides independent control of th e 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, and steering ratio
and rear wheel angle
◆Emergency brake signal
When the brakes are applied suddenly, the stop lights automatically flash to
alert the vehicle behind

3474-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(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. 4 8 2 )
■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
dealer or repairer, or another duly qualified and equipped professional.
■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.