2054-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set speed. If automatic deceleration/acceleration is not appropriate,
adjust the vehicle speed, as well as the distance between your vehicle and vehicles
ahead by applying the brakes etc.
■Cautions regarding the driving assist systems
Observe the following precautions.
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 intended to help the driver 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 no capa bility 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 vehicl e and act appropriately in order to ensure
the safety of all involved.
■To avoid inadvertent cruise control activation
Switch the cruise control off using th e “ON/OFF” button when not in use.
2064-5. Using the driving support systems
IS350/250_U (OM53C50U)
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice or snow
●On steep downhills, or where there are sudden changes between sharp up and down
gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors from
functioning correctly (fog, snow , sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
●During emergency towing
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in front of
you.
As the sensor may not be able to correctly detect these types of vehicles, the approach
warning (P. 201) will not be activated, and a fatal or serious accident may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-vehicle distance control may not function cor-
rectly
Apply the brakes as necessary in the following conditions as the radar sensor may not
be able to correctly detect vehicles ahead, and a fatal or serious accident may result:
●When water or snow thrown up by the surrounding vehicles hinders the functioning
of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly
2194-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
■Sensor detection information
●The sensor’s detection areas are limited to the areas around the vehicle’s front corner
and rear bumpers.
●Certain vehicle conditions and the surround ing environment may affect the ability of
the sensor to correctly detect obstacles. 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 ar e instances in which, because of their shape,
signs and other objects may be judged by the sensor to be closer than they are.
●The shape of the obstacle may prevent the sensor from detecting it. Pay particular
attention 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 will come within the sensor’s detection
areas before the display is shown and the warning beep 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 the volume of the audio system or air flow noise of the air conditioning system.
2404-5. Using the driving support systems
IS350/250_U (OM53C50U)
◆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
◆VGRS (Variable Gear Ratio Steering) (if equipped)
Adjusts the front wheel turning angle in accordance with the vehicle speed
and steering wheel movement
Driving 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.
2414-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
◆Adaptive Variable Suspension system (if equipped)
By independently controlling the dampin g force of the shock absorbers for
each of the 4 wheels according to the road and driving conditions, this system
combines riding comfort with superior steering stability, and helps good vehi-
cle posture. ( P. 2 3 8 )
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, EPS and VGRS (if equipped) systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, steering assist, and if equipped with
VGRS, steering ratio
◆PCS (Pre-Collision System) (if equipped)
P. 2 4 6
◆BSM (Blind Spot Monitor) (if equipped)
P. 2 5 2
The slip indicator light will flash while
the TRAC/VSC systems are operating.
When the TRAC/VSC systems are operating
2464-5. Using the driving support systems
IS350/250_U (OM53C50U)
◆ Pre-collision warning
When a high possibility of a frontal
collision is detected, the pre-colli-
sion system warning light flashes, a
buzzer sounds and a message is
shown on the multi-information dis-
play to urge the driver to take eva-
sive action.
◆Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to ho w strongly the brake pedal is depressed.
The system may not warn the driver using a warning light, warning display and
buzzer when the system detects and judges braking operations.
◆Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warning di splay and buzzer. If the system deter-
mines that a collision is unavoidable, the brakes are automatically applied to
reduce the collision speed.
◆Suspension control (vehicles with Ad aptive Variable Suspension System)
When the system determines that there is a high possibility of a frontal colli-
sion, the operation of Adaptive Variable Suspension System ( P. 2 4 1 ) o p t i -
mally controls the damping force of the shock absorber.
PCS (Pre-Collision System)
: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes are
automatically engaged to lessen im pact as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by operating
the switch. ( P. 2 4 7 )
2484-5. Using the driving support systems
IS350/250_U (OM53C50U)
■The pre-collision system is operational when
The PCS OFF switch is not pressed and the following conditions are met:
●Pre-collision warning:
• Vehicle speed is greater th an about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Pre-collision brake assist:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running
ahead of you is greater than about 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater th an about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Suspension control (vehicles with Ad aptive Variable Suspension System):
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 19 mph (30 km/h).
■Conditions that may trigger the system even if there is no danger of a collision
●When there is an object by the ro adside at the entrance to a curve
●When passing an oncoming vehicle on a curve
●When driving over a narrow iron bridge
●When there is a metal object on the road surface
●When driving on an uneven road surface
●When passing an oncoming vehicle on a left-turn
●When your vehicle rapidly closes on the vehicle in front
●When a grade separation/interchange, sign, billboard, or other structure appears to be
directly in the vehicle’s line of travel
●When there is a metal plate in the road in front of the vehicle on a downhill slope
●When climbing a steep hill causes an over head billboard or other metallic structure to
appear directly in the vehicle’s line of travel
●When driving under an overpass
●When an extreme change in vehicle height occurs
●When passing through certain toll gates
●When passing through a tunnel
●When the radar sensor moves off position due to its surrounding area being subjected
to a strong impact
When the system is activated in the situations described above, there is also a possibility
that the brakes will be applied with a force greater than normal.
260
IS350/250_U (OM53C50U)4-6. Driving tips
●Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine coolant
• Washer fluid
●Have a service technician inspect the condition of the battery.
●Have the vehicle fitted with four snow tires or purchase a set of tire chains for
the rear tires.
*
Ensure that all tires are the specified size and brand, and that chains match the size
of the tires.
*: Tire chains cannot be mounted on the 18-inch tires.
Perform the following according to the driving conditions:
●Do not try to forcibly open a window or move a wiper that is frozen. Pour
warm water over the frozen area to melt the ice. Wipe away the water imme-
diately 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.
Winter driving tips
Carry out the necessary preparations and inspections before driving the vehi-
cle in winter. Always drive the vehicle in a manner appropriate to the prevail-
ing weather conditions.
Preparation for winter
Before driving the vehicle
When driving the vehicle