324 4-5. Using the driving support systems
RX450h_U_OM0E013U WA R N I N G ■
Before using dynamic radar cruise control
Driving safely is the sole responsibility of th e driver. Do not rely solely on the system,
and drive safely by always paying ca reful attention to your surroundings.
The dynamic radar cruise control provides driving assistance to reduce the driver's
burden. However, there are limitatio ns to the assistance provided.
Even when the system is functioning normal ly, the condition of the preceding vehicle as
detected by the system may differ from the condition observed by the driver. There-
fore, the driver must always remain alert, assess the danger of each situation and drive
safely. Relying on this system or assuming the system ensures safe ty while driving can
lead to an accident, resultin g in death or serious injury.■
Cautions regarding the driving assist systems
Observe the following precautions, as there are limitations to the assistance provided
by the system.
Failure to do so may cause an accident resulting in death or serious injury. ●
Assisting the driver to measure following distance
The dynamic radar cruise control is only in tended to help the dr iver in determining
the following distance between the driver’s own vehicle and a designated vehicle
traveling ahead. It is not a mechanism that al lows careless or inattentive driving, and it
is not a system that can assist the driver in low-visibility conditions. It is still necessary
for driver to pay close attention to the vehicle’s surroundings. ●
Assisting the driver to judge proper following distance
The dynamic radar cruise control determines whether the following distance
between the driver’s own vehicle and a designated vehicle traveling ahead is appro-
priate or not. It is not capable of making an y other type of judgement. Therefore, it is
absolutely necessary for the driver to remain vigilant and to determine whether or not
there is a possibility of danger in any given situation. ●
Assisting the driver to operate the vehicle
The dynamic radar cruise control has limited capability to prevent or avoid a collision
with a vehicle traveling ahead. Therefore, if there is ever any danger, the driver must
take immediate and direct control of the vehicle and act appropriately in order to
ensure the safety of all involved. ■
To avoid inadvertent dynamic radar cruise control activation
Switch the dynamic radar cruise control off using the “ON/OFF” button when not in
use.
3454-5. Using the driving support systems
4
Driving
RX450h_U_OM0E013U ■
Sensor detectio n information●
The sensor’s detection areas are limited to the areas around the vehicle’s bumper. ●
Certain vehicle conditions and the surround ing environment may affect the ability of a
sensor to correctly detect an obstacle. Particular instances where this may occur are
listed below.
• There is dirt, snow or ice on the sensor . (Wiping the sensors will resolve this prob-
lem.)
• The sensor is frozen. (Thawing th e area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen may show an abnormal
display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning co nsiderably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines, air
brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under the bumpers is not detected.
• If obstacles draw too close to the sensor.
• A non-genuine Lexus suspension (low ered suspension etc.) is installed.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there are instances in which, because of their shape,
signs and other objects may be judged by a sensor to be closer than they are.●
The shape of the obstacle may prevent a sensor from detecting it. Pay particular atten-
tion to the following obstacles:
• Wires, fences, ropes, etc.
• Cotton, snow and other materials that absorb sound waves
• Sharply-angled objects
•Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your vehi-
cle ●
The following situations may occur during use.
• Depending on the shape of the obstacle and other factors, the detection distance
may shorten, or detect ion may be impossible.
• Obstacles may not be detected if they are too close to the sensor.
• There will be a short delay between obst acle detection and display. Even at slow
speeds, there is a possibility that the obstacle w ill come within the sensor’s detection
areas before the display is shown and the buzzer sounds.
• Thin posts or objects lower than the sensor may not be detected when approached,
even if they have been detected once.
• It might be difficult to hear beeps due to th e volume of audio system or air flow noise
of the air conditioning system.
3814-5. Using the driving support systems
4
Driving
RX450h_U_OM0E013U ◆ 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)
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
◆ Hill-start assist control
Prevents the vehicle from rolling backward when starting on an incline or slip-
pery slope
◆ EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheelDriving assist systems 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.
382 4-5. Using the driving support systems
RX450h_U_OM0E013U ◆ E-Four (AWD models)
Electronic On-Demand AWD system. Automatically switches from front-
wheel drive to all-wheel drive (AWD) according to the driving conditions,
helping to ensure reliable handling and stability. Examples of conditions where
the system will switch to AWD are when cornering, going uphill, starting off or
accelerating, and when the road surface is slippery due to snow, rain, etc.
◆ Adaptive Variable Suspension System (if equipped)
Controls the damping force of the shock absorber of each wheel according to
the road and driving conditions, helping achieve a comfortable ride, excellent
driveability and a high level of stability.
If SPORT S+ mode is selected using the driving mode select switch, the
damping force will become more su itable for sporty driving. ( P. 3 7 8 )
◆ VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, and EPS systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes and hybrid system output
◆ Trailer Sway Control
Helps the driver to control trailer sway by selectively applying brake pressure
for individual wheels and reducing dr iving torque when trailer sway is
detected.
Trailer Sway Control is part of the VSC system and will not operate if VSC
turned off or experi ences a malfunction.
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Driving
RX450h_U_OM0E013U The slip indicator light will flash while
the TRAC/VSC/Trailer Sway Control/
ABS systems are operating.
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce
power from the hybrid system to the wheels. Pressing to turn the system
off may make it easier for you to rock the vehicle in order to free it.
To turn the TRAC system off, quickly
press and release . The “Traction Control Turned Off”
will be shown on the multi-informa-
tion display. Press again to
turn the system back on.When the TRAC/VSC/Trailer Sway Control/ABS systems are operat-
ing
Disabling the TRAC system
384 4-5. Using the driving support systems
RX450h_U_OM0E013U ■
Turning off TRAC, VSC and Tr ailer Sway Control systems
To turn the TRAC, VSC and Trailer Sway Control 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-Collision System), pre-collision brake assist and pre-
collision braking will also be disabled. ( P. 2 9 1 ) ■
When the message is displayed on the mu lti-information display showing that TRAC
has been disabled even if has not been pressed
TRAC and hill-start assist control cannot be operated. Contact your Lexus dealer. ■
Sounds and vibrations caused by the ABS, brake assist, TRAC, VSC, Trailer Sway Con-
trol and hill-start assist control 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 operating sound
ECB operating sound may be hear d in the following 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 sound 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 1 or 2 minutes passed
after the stop of the hybrid system. ■
EPS 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 TRAC, VSC and Trailer Sway Control systems
After turning the TRAC, VSC and Trailer Sway Control systems off, the systems will be
automatically re-enabled in the following situations: ●
When the power switch is turned off ●
If only the TRAC system is turned off, the TRAC will turn on when vehicle speed
increases
If the TRAC, VSC and Trailer Sway Control systems are turned off, automatic re-
enabling will not occur when vehicle speed increases.
3854-5. Using the driving support systems
4
Driving
RX450h_U_OM0E013U ■
Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases. However, when TRAC, VS C and Trailer Sway Control 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 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 P or N (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. ■
Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations: ●
The shift lever is moved to P or N. ●
The accelerator pedal is depressed. ●
The parking brake is engaged. ●
Approximately 2 seconds elapse after the brake pedal is released.
WA R N I N G ■
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 operat ing 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 ■
TRAC may not operate effectively when
Directional control and power may not be achievable while drivin g on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
386 4-5. Using the driving support systems
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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 control 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. ■
When the VSC/Trailer Sway Control is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes. ■
When the TRAC/VSC/Trailer Sway Control systems are turned off
Be especially careful and drive at a speed ap propriate to the road conditions. As these
are the systems to help ensure vehicle st ability and driving force, do not turn the
TRAC/VSC/Trailer Sway Control systems off unless necessary. ■
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 infla-
tion pressure level.
The ABS, TRAC, VSC and Trailer Sway Control systems will not function correctly if
different tires are installed on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels. ■
Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension will affect the driving
assist systems, and may caus e a system to malfunction.■
Trailer Sway Control precaution
The Trailer Sway Control system is not able to reduce trailer sway in all situations.
Depending on many factors such as the condit ions of the vehicle, trailer, road surface,
and driving environment, the Trailer Sway Co ntrol system may not be effective. Refer to
your trailer owner’s manual for information on how to tow your trailer properly. ■
If trailer sway occurs
Observe the following precautions.
Failing to do so may caus e death or serious injury.●
Firmly grip the steering wh eel. Steer straight ahead.
Do not try to control trailer swaying by turning the steering wheel. ●
Begin releasing the accelerator pedal i mmediately but very gradually to reduce
speed.
Do not increase speed. Do not apply vehicle brakes.
If you make no extreme correction with the steering or brakes, your vehicle and trailer
should stabilize. ( P. 2 2 7 )