brakes LEXUS RX450h 2016 User Guide

2294-1. Before driving
4
Driving
RX450h_U_OM0E013U WA R N I N G ■
Hitch
Trailer hitch assemblies have different weight capacities established by the hitch manu-
facturer. Even though the vehicle may be physically capable of towing a higher weight,
the operator must determine the maximum weig ht rating of the particular hitch assem-
bly and never exceed the maximum weight rating specified for the trailer-hitch.
Exceeding the maximum weight rating set by the trailer-hitch manufacturer can cause
an accident resulting in death or serious personal injuries.■
When towing a trailer
Lexus recommends trailers with brakes that conform to any applicable federal and
state/provincial regulations. ●
If the gross trailer weight exceeds unbraked TWR, trailer brakes are required. Lexus
recommends trailers with brakes that conform to all applicable federal and state/pro-
vincial regulations. ●
Never tap into your vehicle’s hydraulic system, as this will lower the vehicle’s braking
effectiveness. ●
Never tow a trailer without using a safety ch ain securely attached to both the trailer
and the vehicle. If damage occurs to the coupling unit or hitch ball, there is danger of
the trailer wandering into another lane.
NOTICE ■
When installing a trailer hitch
Use only the position recommended by your Lexus dealer. Do not install the trailer
hitch on the bumper; this may cause body damage.■
Do not directly splice trailer lights
Do not directly splice trailer lights. Dire ctly splicing trailer lights may damage your
vehicle’s electrical system and cause a malfunction.

2494-2. Driving procedures
4
Driving
RX450h_U_OM0E013U Turns the brake hold system on The brake hold standby indicator
(green) comes on. While the system is
holding the brake, the brake hold oper-
ated indicator (yellow) comes on. ■
Brake hold system operating conditions
The brake hold system cannot be turn ed on in the following conditions:●
The driver’s door is not closed. ●
The driver is not wearing the seat belt.
If any of the conditions above are detected when the brake hold system is enabled, the
system will turn off and the brake hold standby in dicator light will go of f. In addition, if any
of the conditions are detected while the sy stem is holding the brake, a warning buzzer
will sound and a message will be shown on th e multi-information display. The parking
brake will then be set automatically. ■
Brake hold function ●
If the brake pedal is left released for a period of about 3 minutes after the system has
started holding the brake, the parking brake w ill be set automatically. In this case, a
warning buzzer sounds and a message is shown on the multi-information display.●
To turn the system off while the system is holding the brake, firmly depress the brake
pedal and press the button again. ●
The brake hold function may not hold the vehicle when the vehicle is on a steep incline.
In this situation, it may be necessary fo r the driver to apply the brakes. A warning
buzzer will sound and the multi-information di splay will inform the dr iver of this situa-
tion. If a warning message is shown on the multi-information displa y, re a d t h e m e s s a g e
and follow the instructions.Brake Hold The brake hold system keeps the brake applied when the shift lever is in D, S or
N with the system on and the brake pedal has been depressed to stop the vehi-
cle. The system releases the brake when the accelerator pedal is depressed
with the shift lever in D or S to allow smooth start off.

250 4-2. Driving procedures
RX450h_U_OM0E013U ■
When the parking brake is set automatically while the system is holding the brakes
The parking brake will not be released automatically. With the brake pedal depressed,
release the parking brake by operating the parking brake switch, making sure that the
parking brake indicator light goes off. (  P. 2 4 5 )■
If “Brake Hold Fault Depress Brake to Deacti vate Visit Your Dealer” is displayed on the
multi-information display
The system may be malfunctioning. Have the vehicle inspected by your Lexus dealer
immediately. ■
Warning messages and buzzers
Warning messages and buzzers are used to indicate a system malfunction or to inform
the driver of the need for caution. If a warn ing message is shown on the multi-information
display, read the message and follow the instructions.■
If the brake hold operated indicator flashes
 P. 5 3 6
WA R N I N G ■
When the vehicle is on a steep incline
When using the brake hold system on a stee p incline exercise caution. The brake hold
function may not hold the vehicle in such a situation. ■
When stopped on a slippery road
The system cannot stop the vehicle when the gripping ability of the tires has been
exceeded. Do not use the system when stopped on a slippery road.
NOTICE ■
When parking the vehicle
The brake hold system is not designed for use when parking the vehicle for a long
period of time. Turning the power switch of f while the system is holding the brake may
release the brake, which would cause the vehicle to move. When operating the power
switch, depress the brake pedal, shift the shift lever to P and set the parking brake.

2794-5. Using the driving support systems
4
Driving
RX450h_U_OM0E013UPCS (Pre-Collision System) 
 : If equippedThe pre-collision system uses a radar sensor and camera sensor to detect
vehicles and pedestrians
* 1
in front of your vehicle. When the system deter-
mines that the possibility of a frontal collision with a vehicle or pedestrian is
high, a warning operates to urge the driver to take evasive action and the
potential brake pressure is increased to help the driver avoid the collision. If
the system determines that th e possibility of a frontal collision with a vehicle or
pedestrian is extremely high, the brakes are automatically applied
* 2
to help
avoid the collision or help reduce the impact to the vehicle occupants and the
vehicle in the collision.
The pre-collision system can be disabl ed/enabled and the warning timing can
be changed. (  P. 2 8 3 )
* 1
: Depending on the region in which the vehicle was sold, the pedestrian detection
function may not be available. Contact your Lexus dealer for details.
* 2
: Depending on the region in which the ve hicle was sold, the pre-collision braking
function (automatic braking function) may not be available. Contact your Lexus
dealer for details.

280 4-5. Using the driving support systems
RX450h_U_OM0E013U ◆ Pre-collision warning
When the system determines that
the possibility of a frontal collision is
high, a buzzer will sound and a warn-
ing message will be displayed on the
multi-information display to urge the
driver to take evasive action.
◆ Pre-collision brake assist
When the system determines that the po ssibility of a frontal collision is high,
the system applies greater braking force in relation to how strongly the brake
pedal is depressed.
◆ Pre-collision braking
* 3
When the system determines that the po ssibility of a frontal collision is high,
the system warns the driver. If the system determines that the possibility of a
collision is extremely high, the brakes are automatically applied to help avoid
the collision or reduce the collision speed.
* 3
: Depending on the region in which the vehi cle was sold, the pre-collision braking func-
tion may not be available.
◆ Suspension control (if equipped)
When the system determines that the po ssibility of a frontal collision is high,
the Adaptive Variable Suspension System (  P. 382) will control the damping
force of the shock absorbers.

290 4-5. Using the driving support systems
RX450h_U_OM0E013U • After the hybrid system has started the vehicle has not been driven for a certain
amount of time
• While making a left/right turn and for a few seconds after making a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or lowered, such as when the road surface is
uneven or undulating
• If the wheels are misaligned
• If a wiper blade is blocking the camera sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill ●
In some situations such as the following, su fficient braking force may not be obtained,
preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake
parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively worn,
improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery surface ●
Some pedestrians such as the following may not be detected by the radar sensor and
camera sensor, preventing the system from operating properly
* 4
:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5
ft. (2 m)
• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), making their sil-
houette obscure
• Pedestrians who are carrying large baggag e, holding an umbrella, etc., hiding part
of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller, wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as
their surroundings
• Pedestrians near walls, fences, guardrails, or large objects
• Pedestrians who are on a metal object (man hole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from behind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view
mirror, etc.)
* 4
: Depending on the region in which the ve hicle was sold, the pedestrian detection
function may not be available.

314 4-5. Using the driving support systems
RX450h_U_OM0E013U This mode employs a radar sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead, determines the current vehicle-to-vehicle
following distance, and operates to main tain a suitable following distance from
the vehicle ahead. Note that vehicle-to-vehicle distance will close in when traveling on long downhill
slopes.
Example of constant speed cruising
When there are no vehicles ahead The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle dis-
tance can also be set by operating th e vehicle-to-vehicle distance button.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears When a vehicle is detected running ahead of you, the system automatically deceler-
ates your vehicle. When a greater reduction in vehicle speed is necessary, the system
applies the brakes (the stop lights will come on at this time). The system will respond to
changes in the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle
distance set by the driver. Approach wa rning warns you when the system cannot
decelerate sufficiently to prevent your ve hicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your ve hicle will also stop (vehicle is stopped by
system control). After the vehicle ahead starts off, pushing the cruise control lever up
or depressing the accelerator peda l will resume follow-up cruising.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed The system accelerates until the set speed is reached. The system then returns to con-
stant speed cruising.Driving in vehicle-to-vehicle distance control mode
1
2
3

326 4-5. Using the driving support systems
RX450h_U_OM0E013U This mode employs a radar sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead, determines the current vehicle-to-vehicle
following distance, and operates to main tain a suitable following distance from
the vehicle ahead. Note that vehicle-to-vehicle distance will close in when traveling on long downhill
slopes.
Example of constant speed cruising
When there are no vehicles ahead The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle dis-
tance can also be set by operating th e vehicle-to-vehicle distance button.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears When a vehicle is detected running ahead of you, the system automatically deceler-
ates your vehicle. When a greater reduction in vehicle speed is necessary, the system
applies the brakes (the stop lights will come on at this time). The system will respond to
changes in the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle
distance set by the driver. Approach wa rning warns you when the system cannot
decelerate sufficiently to prevent your ve hicle from closing in on the vehicle ahead.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed The system accelerates until the set speed is reached. The system then returns to con-
stant speed cruising.Driving in vehicle-to-vehicle distance control mode
1
2
3

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.