brake LEXUS NX300h 2015 Repair Manual

3074-5. Using the driving support systems
4
Driving
NX300h_U_OM78007U 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.
■
Turning off both TRAC and VSC systems
To turn the TRAC and VSC systems off, press and hold for more than 3 seconds
while the vehicle is stopped.
The VSC OFF indicator will come on and th e “Traction Control Turned Off” will be
shown on the multi- information display.
*Press again to turn the systems back on.
* : On vehicles with pre-collision system, pre-collision brake assist and pre-collision
braking will also be disabled. The PCS warn ing light will come on and the message will
be shown on the multi-information display. (  P. 313) ■
When the message is displayed on the mu lti-information display showing that TRAC
has been disabled even if the has not been pressed
TRAC cannot be operated. Contact your Lexus dealer. ■
Sounds and vibrations caused by the ABS, brake assist, TRAC, VSC 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. ●
The brake pedal may pulsate slight ly after the ABS is activated.●
The brake pedal may move down slig htly after the ABS is activated.Disabling the TRAC system

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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. ■
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. ■
Automatic reactivation of TRAC and VSC systems
After turning the TRAC and VSC 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 both the TRAC and VSC systems are turn ed off, automatic re-enabling will not
occur when vehicl e speed increases.■
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.

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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 road. ■
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. ■
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 TRAC, VSC and/or ABS are 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 system 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 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 and VSC 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.

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)

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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.

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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.

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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.

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Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre- collision system is in tended to assist the
driver in avoiding collisions through the process of LOOK-JUDGE-ACT. There are
limits to the degree of assistance the system can provide, so please keep in mind the
following important points. ●
Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the vehicle,
and only within a limited range. It is not a mechanism that allows careless or inatten-
tive driving, and it is not a system that can assist the driver in low-visibility conditions. It
is still necessary for the driver to pay cl ose attention to the vehicle’s surroundings.●
Assisting the driver in making correct judgement
When attempting to estimate the possibility of a collision, the only data available to
the pre-collision system is that from obstacle s it has detected dire ctly in front of the
vehicle. Therefore, it is absolutely necess ary for the driver to remain vigilant and to
determine whether or not there is a possib ility of collision in any given situation.●
Assisting the driver in taking action
The pre-collision system’s braking assist feat ure is designed to help reduce the sever-
ity of a collision, and so only acts when the system has judged that a collision is
unavoidable. This system by itself, without the proper operations of the driver, is not
capable of automatically avoiding a collision or bringing the vehicle to a stop safely.
For this reason, when encountering a dangerous situation the driver must take direct
and immediate action in order to en sure the safety of all involved.

324 4-6. Driving tips
NX300h_U_OM78007UHybrid vehicle driving tips ◆ Using Eco drive mode
When using Eco drive mode, the torq ue corresponding to the accelerator
pedal depression amount can be generate d more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heat-
ing/cooling) will be minimized, improving the fuel economy. (  P. 3 0 3 )
◆ Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicator needle of Hybrid
System Indicator within Eco area. (  P. 100)
◆ Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic, etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, wh en using the air conditioning system,
etc., the hybrid battery (traction battery) power is consumed.
◆ Accelerator pedal/brake pedal operation ●
Drive your vehicle smoothly. Avoid ab rupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) wi thout having to use gasoline engine
power. ●
Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) power, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly
released.
◆ When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.For economical and ecological driving, pay attention to the following points:

3254-6. Driving tips
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Driving
NX300h_U_OM78007U ◆ Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When drivin g in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
◆ Highway driving
Control and maintain the vehicle at a co nstant speed. Before stopping at a toll
booth or similar, allow plenty of time to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
◆ Air conditioning
Use the air conditioning only when necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient temperature is high, use the recirculated air
mode. Doing so will help to reduce th e burden on the air conditioning system
and reduce fuel consumption as well.
In winter: Because the gasoline engine will not automatically cut out until it
and the interior of the vehicle are warm, it will consume fuel. Also, fuel con-
sumption can be improved by avoiding overuse of the heater.
◆ Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amou nts of friction, their use on dry roads
can lead to poor fuel economy. Use ti res that are appropriate for the season.
◆ Luggage
Carrying heavy luggage will lead to poor fuel economy. Avoid carrying
unnecessary luggage. Installing a large roof rack will also cause poor fuel
economy.
◆ Warming up before driving
Since the gasoline engine starts up and cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short dis-
tances will cause the engine to repeated ly warm up, which can lead to excess
fuel consumption.