brakes LEXUS RX450h 2015 User Guide

2462-4. Using other driving systems
CAUTION■
Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate sp eed 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 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, sn ow, sandstorm, heavy rain, etc.)●
When an approach warning buzzer is heard often●
When your vehicle is towing a trailer or 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. 241) 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 (tra ilers with no load on board etc.)
●
Motorcycles traveling in the same lane

2472-4. Using other driving systems
2
When driving CAUTION■
Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the foll owing 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 function-
ing of the sensor●
When your vehicle is pointing upwards (caused by a heavy load in the luggage
compartment 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■
Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function co rrectly and could result in an accident.●
Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.●
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by your Lexus dealer.●
Do not disassemble the sensor.●
Do not attach accessories or stickers to the sensor, grille cover or surrounding
area.
●
Do not modify or paint the sensor and grille cover.
●
Do not replace them with non-genuine parts.

2562-4. Using other driving systems
■
Sensor detection information ●
Certain vehicle conditions and the su rrounding 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 a sensor.
• A sensor is frozen.
• A sensor is covered in any way.
• The vehicle is leaning considerably 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 sensor s in the vicinity.
• A sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or radio antenna.
• Towing eyelets are installed.
• A bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or right-angled curb.
• In harsh sunlight or intense cold weather.
• A non-genuine Lexus suspension (low ered suspension, etc.) is installed.
In addition to the examples above, there are instances in which, because of their
shapes, signs and other objects may be judg ed by a sensor to be closer than they
are. ●
The shape of the obstacle may prevent a sensor from detecting it. Pay particular
attention to the following obstacles:
• Wires, fences, ropes, etc.
• Cotton, snow and other materi als that absorb sound waves
• Sharply-angled objects
•Low obstacles
• Tall obstacles with upper sections projec ting outwards in the direction of your
vehicle
■
If a message is displayed
 P. 74 3

2712-4. Using other driving systems
2
When driving Driving assist systems To help enhance driving safety and performance, the following systems
operate 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.
■ 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
■ 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  P. 2 76
■ EPS (Electric Power Steering) Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel
■ 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 sur-
faces by controlling the brakes and hybrid system output.
■ PCS (Pre-Collision System) (if equipped)
 P. 2 7 8
■ BSM (Blind Spot Monitor) (if equipped)
 P. 2 8 6

2762-4. Using other driving systems
Hill-start assist control
■
Hill-start assist control can be operated when ●
The shift lever is in a position other than P.●
The parking brake is not applied.●
The accelerator peda l is not depressed.■
Hill-start assist control ●
While hill-start assist control is operating, the brakes remain automatically
applied after the driver releases the br ake pedal. The stop lights and the high
mounted stoplight turn on.●
Hill-start assist control operates for about 2 seconds after the brake pedal is
released.●
If the slip indicator does not flash and the buzzer does not sound when the brake
pedal is further depressed, slightly redu ce the pressure on the brake pedal (do
not allow the vehicle to roll backward) and then firmly depress it again. If the sys-
tem still does not operate, check if th e operating conditions explained above
have been met.Hill-start assist control helps to prevent the vehicle from rolling backwards
when starting on an incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely. A buzzer will sound once to
indicate the system is activated.
The slip indicator will also start
flashing.

2782-4. Using other driving systems
Pre-Collision System When the radar sensor detects the possib ility of a frontal collision, the pre-
collision system such as the brakes and seat belts are automatically
engaged to lessen impact as well as vehicle damage.
■ Pre-collision seat belts (front seat belts only) If the pre-collision sensor detects that a collision is unavoidable, the pre-
collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or loses
control of the vehicle. (  P. 1 0 0 )
However, the system will not operate in the event of skidding when the
VSC system is disabled.
■ Pre-collision brake assist When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how 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, warnin g display and buzzer. If the system
determines that a collision is unavoidable, the brakes are automatically
applied to reduce the collision speed. Pre-collision braking can be dis-
abled using the pre-collision braking off switch.
 : If equipped

2812-4. Using other driving systems
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When driving ■
Conditions that may trigger the system even if there is no possibility of collision ●
When there is an object by the roadside 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 climbing a steep hill causes an over head billboard or ot her metallic struc-
ture to appear directly in the vehicle's line of travel●
When an extreme change in vehicle height occurs●
When the axis of the radar is out of adjustment●
When passing through certain toll gates●
When driving on a bridge●
When passing through a tunnel
When the system is activated in the situations described above, there is also a possi-
bility that the seat belts will retract quickly and the brakes will be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten it.■
Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may also be
occasions when the sensor cannot detect pedestrians, animals, bicycles, motorcy-
cles, trees, or snowdrifts.

2852-4. Using other driving systems
2
When driving CAUTION■
When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary in any of the following situations: ●
When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor●
When your vehicle is pointing upwards (caused by a heavy load in the luggage
compartment etc.)●
Vehicles that cut in suddenly●
Vehicles with small rear ends (tra ilers with no load on board etc.)●
Motorcycles traveling in the same lane■
Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively: ●
Keep the sensor and front grille clean at all times.
Clean the sensor and front grille with a so ft cloth so you do not mark or damage
them.●
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off po sition, the system may become inaccurate
or malfunction. If the sensor or surround ing area is subject to a strong impact,
always have the area inspected an d adjusted by your Lexus dealer.●
Do not disassemble the sensor.●
Do not attach accessories or stickers to the sensor, grille or surrounding area.●
Do not modify or paint the sensor and grille cover.

2942-5. Driving information
■
Additional information for off-road driving
For owners in U.S. mainland, Hawaii and Puerto Rico:
To obtain additional information pertaining to driving your vehicle off-road, consult
the following organizations. ●
State and Local Parks and Recreation Departments●
State Motor Vehicle Bureau●
Recreational Vehicle Clubs●
U.S. Forest Service and Bureau of Land Management
CAUTION■
Off-road driving precautions
Always observe the following precautions to minimize the risk of death or serious
injury or damage to your vehicle: ●
Drive carefully when off the road. Do not take unnecessary risks by driving in
dangerous places.●
Do not grip the steering wheel spokes wh en driving off-road. A bad bump could
jerk the wheel and injure your hands. Keep both hands and especially your
thumbs on the outside of the rim.●
Always check your brakes for effectiveness immediately after driving in sand,
mud, water or snow.●
After driving through tall grass, mud, rock , sand, water, etc., check that there is no
grass, bush, paper, rags, stone, sand, etc. adhering or trapped to the underbody.
Clear off any such matter from the underbody. If the vehicle is used with these
materials trapped or adhering to the underbody, a breakdown or fire could occur.●
When driving off-road or in rugged te rrain, do not drive at excessive speeds,
jump, make sharp turns, strike objects, etc. This may cause loss of control or vehi-
cle rollover causing death or serious injury. You are also risking expensive dam-
age to your vehicle’s suspension and chassis.

3022-5. Driving information
Winter driving tips Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the ve hicle in a manner appropriate to the
prevailing weather conditions.
■ Pre-winter preparations
● Use fluids that are appropria te to the prevailing outside tempera-
tures.
• Engine oil
• Engine coolant
• Power control unit coolant
• Washer fluid
● Have a service technician inspect the condition of the 12-volt bat-
tery.
● Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the front tires. Ensure that all tires are the same size and brand, and that chains match
the size of the tires.
■ Before driving the vehicle
Perform the following accord ing to the driving conditions:
● Do not try to forcibly open a w indow 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 accumu lated on the air inlet vents in
front of the windshield.
● Check for and remove any exce ss 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.