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3984-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(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 vehi-
cle in accordance 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 driv-
ing 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.
394)
LDH (Lexus Dynamic Handling system) (if equipped)
Provides independent control of the VGRS, DRS and EPS. Con-
tributes 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,
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
Page 411 of 1014
4004-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
The slip indicator light will flash
while the TRC/VSC/ABS sys-
tems are operating.
If the vehicle gets stuck in fresh snow or mud, the TRC and VSC
systems may reduce power from the hybrid system to the wheels.
You may need to turn the system off to enable you to rock the vehi-
cle in order to free it.
Turning off the TRC system only
To turn the TRC system off,
quickly press and release the
switch.
The “TRC OFF” will be shown
on the multi-information dis-
play. Press the switch again to
turn the system back on.
When the TRC/VSC/ABS systems are operating
Disabling the TRC/VSC systems
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4024-5. Using the driving support system
GS450h_300h_OM_OM30D53E_(EE)
When the message is displayed on the multi-information display showing that
TRC has been disabled even if the VSC OFF switch has not been pressed
TRC 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 from 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 dis-
abled. However, the position will return to normal after VGRS is reacti-
vated.
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.
Sounds and vibrations caused by the ABS, brake assist, VSC, TRC and
VGRS systems
A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, when the hybrid system is started or just after the
vehicle begins to move. This sound does not indicate that a malfunction has
occurred in any of these 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.
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.
Reactivation of the TRC/VSC systems
Even after the TRC/VSC systems have been turned off, turning the hybrid
system off and then on again will automatically reactivate the TRC/VSC sys-
tems.
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4034-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
Reactivation of the TRC system linked to vehicle speed
When only the TRC system is turned off, the TRC system will turn on when
vehicle speed increases. However, when both TRC and VSC systems are
turned off, the systems will not turn on even 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 normal within 10 minutes.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a
warning message will be shown on the multi-information display.
Operating conditions of emergency brake signal
When the following three conditions are met, 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 vehicle deceleration that this is a sudden braking operation.
Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off 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 brak-
ing operation.
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4054-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and
total load capacity. In addition, make sure that the tires are inflated to the
recommended tire inflation pressure level.
The ABS, TRC and VSC systems will not function correctly if different
tires are installed on the vehicle.
Contact any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional for further information when replacing tires or
wheels.
Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will
affect the driving assist systems, and may cause a system to malfunction.
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4074-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
Suspension control (if equipped)
When the system determines that there is a high possibility of a
frontal collision, the operation of AVS (P. 398) optimally con-
trols the damping force of the shock absorber.
Steering control (if equipped)
There is a high possibility of collision and if the steering wheel is
operated, the steering angles of the front and rear wheels and the
heaviness of the steering wheel are controlled by LDH, thus
heightening responsiveness in response to the steering operation.
Driver monitor system (if equipped)
When the system determines that there is a possibility of a colli-
sion, and either the driver is not facing forward or the driver’s
eyes are closed, PCS warnings are given in advance to warn the
driver. If the system determines that the conditions to operate
pre-crash alert braking have been met even when the possibility
of a collision increases further, pre-crash alert braking will oper-
ate.
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4354-6. Driving tips
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
Perform the following according to the driving conditions:
Do not try to forcibly open a window or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
Check for and remove any excess ice or snow that may have
accumulated on the exterior lights, vehicle’s roof, chassis, around
the tires or on the brakes.
Remove any snow or mud from the bottom of your shoes before
getting in the vehicle.
Accelerate the vehicle slowly, keep a safe distance between you
and the vehicle ahead, and drive at a reduced speed suitable to road
conditions.
Park the vehicle and move the shift lever to P without setting the
parking brake. The parking brake may freeze up, preventing it from
being released. If necessary, block the wheels to prevent inadver-
tent sliding or creeping.
Before driving the vehicle
When driving the vehicle
When parking the vehicle
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4384-6. Driving tips
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehicle control and cause death or
serious injury.
Use tires of the specified size.
Maintain the recommended level of air pressure.
Do not drive at speeds in excess of the speed limit or the speed limit spec-
ified for the snow tires being used.
Use snow tires on all, not just some wheels.
Do not use LKA (Lane-Keeping Assist) system.
Driving with tire chains (vehicles with front and rear tires of the same size
except for the vehicles with LDH and 19 inch tires)
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in the vehicle being unable to be driven safely,
and may cause death or serious injury.
Do not drive in excess of the speed limit specified for the tire chains being
used, or 50 km/h (30 mph), whichever is lower.
Avoid driving on bumpy road surfaces or over potholes.
Avoid sudden acceleration, abrupt steering, sudden braking and shifting
operations that cause sudden engine braking.
Slow down sufficiently before entering a curve to ensure that vehicle con-
trol is maintained.
Do not use LKA (Lane-Keeping Assist) system.