brake sensor LEXUS NX300h 2015 User Guide

310 4-5. Using the driving support systems
NX300h_U_OM78007UPCS (Pre-Collision System) 
◆ Pre-collision warning
When a high possibility of a frontal
collision is detected, a buzzer
sounds and a message is shown on
the multi-information display to urge
the driver to take evasive 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.
◆ Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using warning display and buzzer. If the system determines that a colli-
sion is unavoidable, the brakes are automatically applied to reduce the colli-
sion speed.
 : If equippedWhen the radar sensor detects possibilit y of a frontal collision, brakes are
automatically engaged to lessen im pact as well as vehicle damage.
The alert timing for the pre-collision system can be changed or turned ON/
OFF, as necessary, by operating the switch. (  P. 311)

312 4-5. Using the driving support systems
NX300h_U_OM78007U ■
The pre-collision system is operational when
The pre-collision system is on (  P. 311) 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 7 mph (10 km/h). ●
Pre-collision brake assist:
• The VSC is not turned off.
• 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 is not turned off.
• 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 7 mph (10 km/h).■
Conditions that may trigger the system even if there is no possibility of a collision
If the following obstructs the front of the sens or, the system judges that a collision may be
possible and operates. ●
When passing by a vehicle while making left or right turns or passing a vehicle in an
opposite lane. ●
When the vehicle rapidly approaches an object in front of it (such as another vehicle,
toll gate, etc.) ●
When climbing a steep hill, etc., and there are structures in the upper region of the road
(billboards, low ceilings , street lamps, etc.)●
When driving through narrow passages or places with low ceilings (bridges, tunnels,
overhead passes, etc.) ●
When driving on an uneven road surface ●
When metal objects are on the road surface causing level differences or protrusions in
the road ●
When an extreme change in vehicle height occurs ●
When the radar sensor moves off position du e to its surrounding area being subjected
to a strong impact. ●
When there is an obstacle on the side of an entrance of a curb for road (guardrails, etc.) ●
When your vehicle is tilted upwards (due to towing a trailer or during emergency tow-
ing, heavy loads in the lu ggage compartment, etc.).
When the system is activated in the situations described above, ther e is also a possibility
that the brakes will be applied wi th a force greater than normal.■
Obstacles not detected
The sensor cannot detect plasti c obstacles such as traffic co nes. There may also be occa-
sions when the sensor cannot detect pedestrians, animals, bicycles, motorcycles, trees,
or snowdrifts.

3134-5. Using the driving support systems
4
Driving
NX300h_U_OM78007U ■
Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:●
On roads with sharp bends or uneven surfaces ●
If a vehicle suddenly moves in front of your vehicle, such as at an intersection ●
If a vehicle suddenly cuts in front of your vehicle, such as when overtaking ●
In inclement weather such as heav y rain, fog, snow or sand storms●
When your vehicle is skidding with the VSC system off ●
When an extreme change in vehicle height occurs ●
When the radar sensor moves off position du e to its surrounding area being subjected
to a strong impact ●
Due to greatly turning the wheel when an obstacle suddenly appears ahead ■
Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc., that results in the sensors
being unable to detect obstacles, the pre-collision syst em will be automatically disabled.
In this case, the system will not activate even if there is a collision possibility.■
When there is a malfunction in the system, or if the system is temporarily unavailable
The PCS warning light flashes and a warning message is shown on the multi-information
display. If a warning message is shown on th e multi-information display, read the message
and follow the instructions. ■
When the TRAC and VSC are turned off ●
When the TRAC and VSC operations are turned off (  P. 307), the pre-collision brake
assist and pre-collision braking are also turned off. However, the alert function oper-
ates. ●
The PCS warning light turns on and the “V SC Turned Off Pre-Collision Brake System
Unavailable” is shown on the multi-information display. ■
Certification 
For vehicles sold in the U.S.A.
FCC ID: HYQDNMWR007
This device complies with part 15 of the FC C Rules. Operation is subject to the following
two conditions: (1) This device may not caus e harmful interference, and (2) this device
must accept any interference received, incl uding interference that may cause undesired
operation.
FCC WARNING
Changes or modifications not expressly approved by the party responsible for compli-
ance could void the user’s authority to operate the equipment.
Radio frequency radiation exposure Information:
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled
environment.
This equipment should be installed and operated with minimum distance of 20 cm
between the radiator (antenna) and your body.
This transmitter must not be co-located or operating in conjunction with any other
antenna or transmitter. 
For vehicles sold in Canada
This device complies with Industry Canada licence-exempt RSS standard(s).
Operation is subject to the following two co nditions: (1) this device may not cause inter-
ference, and (2) this device must accept any interference, including interference that
may cause undesired operation of the device.

314 4-5. Using the driving support systems
NX300h_U_OM78007U WA R N I N G ■
Limitations of the pre-collision system
It is the driver’s responsibility to drive safely. The driver should be aware of the sur-
roundings and strive for safe driving.
Do not rely on the pre-collision system inst ead of normal braking operations. This sys-
tem does not avoid or reduce collisions in every situation.
Overly relying on the system and entrusting it with safety may cause an unexpected
accident which could lead to death or serious injury.
Although the system is designed for the pu rpose to support in evading collisions or
reducing the damage of a collision, the effect changes according to various conditions.
(  P. 312) Therefore, it does not always provide the same performance. Also, the pre-
collision braking does not work depending on the operating conditions of the driver.
When the driver has stepped on the brake pedal and is operating the steering wheel,
the system judges that the driver is takin g evasive action and the automatic braking
may not operate. ■
Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively.
Otherwise, the system may not function correctly and could result in an accident. ●
Keep the sensor and front grille cover clean at all times.
Clean the sensor and front grille cover with a soft cloth so you do not mark or dam-
age them. ●
Do not subject the sensor or surr ounding area to a strong impact.
If the sensor moves even slightly off position, the system may not normally or malfunc-
tion. 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. ●
If the radar sensor needs to be re placed, contact your Lexus dealer.

660 What to do if... (Troubleshooting)
NX300h_U_OM78007U ●
The seat belt reminder light is flashing
Are the driver and the front passenger wearing the seat belts? (  P. 5 6 7 )●
The parking brake indicator is on
Is the parking brake released? (  P. 2 1 3 )
Depending on the situation, other type s of warning buzzer may also sound.
(  P. 5 6 5 , 5 7 2 ) ●
Did anyone inside the vehicle open a door during setting the alarm?
The sensor detects it and the alarm sounds. (  P. 8 8 )
To stop the alarm, turn the power switch to ON mode or start the hybrid system.●
Is the message displayed on the multi-information display?
Check the message on the multi-information display. (  P. 5 7 2 )●
When a warning light turns on or a warning message is displayed, refer to
P. 5 6 5 , 5 7 2 . A warning buzzer sounds during driving
An alarm is activated and the horn sounds
A warning buzzer sounds when leaving the vehicle
A warning light turns on or a warning message is displayed