brake Lexus IS300h 2017 Owner's Guide

2674-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
WARNING
■Limitations of the pre-collision system
●The driver is solely responsible for safe driving. Always drive safely, taking care to
observe your surroundings.
Do not use the pre-collision sy stem instead of normal braking operations under any circumstances. This system will not preven t collisions or lessen collision damage or
injury in every situation. Do not overly rely on this system. Failure to do so may lead to
an accident, resulting in death or serious injury.
●Although this system is designed to help avoid a collision or help reduce the impact of
the collision, its effectiveness may change according to various conditions, therefore
the system may not always be able to achieve the same level of performance. Read the following cond itions carefully. Do not overly rely on this system and always
drive carefully.
• Conditions under which the system may oper ate even if there is no possibility of a collision: P. 274
• Conditions under which the syst em may not operate properly: P. 276
●Do not attempt to test the operation of the pre-collision system yourself, as the system
may not operate properly, possib ly leading to an accident.
■Pre-collision braking*3
●When the pre-collision braking function is operating, a large amount of braking force
will be applied.
●If the vehicle is stopped by the operation of the pre-collision braking function, the pre- collision braking function operation will be canceled after approximately 2 seconds.
Depress the brake pedal as necessary.
●The pre-collision braking function may no t operate if certain operations are per- formed by the driver. If the accelerator pedal is being depressed strongly or the steer-
ing wheel is being turned, the system may determine that the driver is taking evasive
action and possibly prevent the pre-coll ision braking function from operating.
●In some situations, while the pre-collision braking function is operating, operation of
the function may be canceled if the accelerator pedal is depressed strongly or the
steering wheel is turned and the system dete rmines that the driver is taking evasive action.
●If the brake pedal is being depressed, the system may determine that the driver is tak-
ing evasive action and possibly delay the op eration timing of the pre-collision braking function.
*3: Depending on the region in which the vehicle was sold, the pre-collision braking
function may not be available.

2704-5. Using the driving support systems
IS300h_EE(OM53D89E)
■Operational conditions
Availability of the pedestrian detection function and pre-collision braking function
depend on the region in which the vehicle was sold.
Read the following for details:
Region A (The pedestrian detection function and pre-collision braking function are available)
The pre-collision system is enabled and the sy stem determines that the possibility of a
frontal collision with a vehicle or pedestrian is high.
Each function is operationa l at the following speeds:
●Pre-collision warning:
• Vehicle speed is between approximately 10 and 180 km/h (7 and 110 mph). (For detecting a pedestrian, vehicle speed is between approximately 10 and 80 km/h [7
and 50 mph].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 10 km/h (7 mph) or more.
●Pre-collision brake assist:
• Vehicle speed is between approximately 30 and 180 km/h (19 and 110 mph). (For
detecting a pedestrian, vehicle speed is between approximately 30 and 80 km/h
[19 and 50 mph].) • The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 30 km/h (19 mph) or more.
●Pre-collision braking:
• Vehicle speed is between approximately 10 and 180 km/h (7 and 110 mph). (For
detecting a pedestrian, vehicle speed is between approximately 10 and 80 km/h [7 and 50 mph].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 10 km/h (7 mph) or more.
The system may not operate in the following situations:
●If a 12-volt battery terminal has been disconnected and reconnected and then the vehi-
cle has not been driven for a certain amount of time
●If the shift lever is in R
●If VSC is disabled (only the pre-collis ion warning function will be operational)
●If the PCS warning light is flashing or illuminated
RegionsFunction availability
Region AThe pedestrian detection function and pre-collision braking function are available
Region BThe pedestrian detection function is not available and the pre-
collision braking function is available
Region CThe pedestrian detection func tion and pre-collision braking
function are not available

2714-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
Region B
(The pedestrian detection function is not available and the pre-collision braking func- tion is available)
The pre-collision system is enabled and the sy stem determines that the possibility of a
frontal collision with a vehicle is high.
Each function is operationa l at the following speeds:
●Pre-collision warning:
• Vehicle speed is between approximately 15 and 180 km/h (10 and 110 mph). • The relative speed between your vehicle and the vehicle ahead is approximately 10
km/h (7 mph) or more.
●Pre-collision brake assist:
• Vehicle speed is between approximately 30 and 180 km/h (19 and 110 mph).
• The relative speed between your vehicle and the vehicle ahead is approximately 30 km/h (19 mph) or more.
●Pre-collision braking:
• Vehicle speed is between approximately 15 and 180 km/h (10 and 110 mph).
• The relative speed between your vehicle and the vehicle ahead is approximately 10
km/h (7 mph) or more. The system may not operate in the following situations:
●If a 12-volt battery terminal has been disconnected and reconnected and then the vehi-
cle has not been driven for a certain amount of time
●If the shift lever is in R
●If VSC is disabled (only the pre-collis ion warning function will be operational)
●If the PCS warning light is flashing or illuminated

2724-5. Using the driving support systems
IS300h_EE(OM53D89E)
Region C
(The pedestrian dete ction function and pre-collision braking function are not avail- able)
The pre-collision system is enabled and the sy stem determines that the possibility of a
frontal collision with a vehicle is high.
Each function is operationa l at the following speeds:
●Pre-collision warning:
• Vehicle speed is between approximately 15 and 180 km/h (10 and 110 mph). • The relative speed between your vehicle and the vehicle ahead is approximately 10
km/h (7 mph) or more.
●Pre-collision brake assist:
• Vehicle speed is between approximately 30 and 180 km/h (19 and 110 mph).
• The relative speed between your vehicle and the vehicle ahead is approximately 30 km/h (19 mph) or more.
The system may not operate in the following situations:
●If a 12-volt battery terminal has been disconnected and reconnected and then the vehi- cle has not been driven for a certain amount of time
●If the shift lever is in R
●If VSC is disabled (only the pre-collis ion warning function will be operational)
●If the PCS warning light is flashing or illuminated

2774-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
• 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 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
• If the radar sensor or ca mera sensor is misaligned
●In some situations such as the following, sufficient braking force may not be obtained,
preventing the system fr om 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 1 m (3 .2 ft.) or taller than approximately 2 m (6.5 ft.)
• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), making their sil-
houette obscure • Pedestrians who are carrying large baggage, 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 meta l object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast • Pedestrians who are changing speed abruptly
• Pedestrians running out from be hind 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.
• If the front of the vehicle is raised or low-
ered

2784-5. Using the driving support systems
IS300h_EE(OM53D89E)
■If the PCS warning light flashes and a warning message is displayed on the multi-infor-
mation display
The pre-collision system may be temporarily unavailable or there may be a malfunction
in the system.
●In the following situations, the warning light will turn off, the message will disappear and the system will become operational when normal operating conditions return:
• When the radar sensor or camera sensor or the area around either sensor is hot,
such as in the sun • When the radar sensor or came ra sensor or the area around either sensor is cold,
such as in an extremely cold environment
• When the radar sensor or front grille embl em is dirty or covered with snow, etc. • When the part of the windshield in front of the camera sensor is fogged up or cov-
ered with condensation or ic e (Defogging the windshield: P. 474)
• If the camera sensor is obstructed, such as when the hood is open or a sticker is attached to the windshield near the camera sensor
●If the PCS warning light continues to flash or the warning message does not disappear, the system may be malfunctioning. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authoriz ed repairer, or any reliable repairer immediately.
■If VSC is disabled
●If VSC is disabled (P. 354), the pre-collision brake assist and pre-collision braking
functions are also disabled.
●The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake System Unavailable” will be displayed on the multi-information display.

2964-5. Using the driving support systems
IS300h_EE(OM53D89E)
This mode employs a radar sensor to detect the presence of vehicles up to
approximately 100 m (328 ft.) ahead, de termines the current vehicle-to-vehicle
following distance, and operates to main tain a suitable following distance from
the vehicle ahead.
Note that vehicle-to-v ehicle 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 the vehicle-to-vehicle distance button.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving sl ower 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 sufficie ntly to prevent your vehicle 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

2994-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
Pressing the button changes the vehi-
cle-to-vehicle distance as follows:
Long
Medium
Short
The vehicle-to-vehicle distance is set
automatically to long mode when the power switch is turned to ON mode.
If a vehicle is running ahead of you, the preceding vehicle mark will also be displayed.
Select a distance from the table below. Note that the distances shown corre-
spond to a vehicle speed of 80 km/h (50 mph). Vehicle-to-vehicle distance
increases/decreases in acco rdance with vehicle speed.
Pulling the lever toward you cancels
the speed control.
The speed control is also canceled when
the brake pedal is depressed.
Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
However, cruise control does not
resume when the vehicle speed is
approximately 40 km/h (25 mph) or less.
Changing the vehicle-to-vehicle distance (vehicle-to-vehicle distance
control mode)
Preceding
vehicle mark
1
2
3
Vehicle-to-vehicle distance settings (vehicle-to-vehicle distance con-
trol mode)
Distance optionsVehicle-to-vehicle distance
LongApproximately 50 m (160 ft.)
MediumApproximately 40 m (130 ft.)
ShortApproximately 30 m (100 ft.)
Canceling and resuming the speed control
1
2

3004-5. Using the driving support systems
IS300h_EE(OM53D89E)
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehicle-
to-vehicle distance.
■Warnings may not occur when
In the following instances, warnings ma y not occur even when the vehicle-to-
vehicle distance is small.
●When the speed of the preceding vehi cle matches or exceeds your vehicle
speed
●When the preceding vehicle is traveling at an extremely slow speed
●Immediately after the crui se control speed was set
●When depressing the accelerator pedal
Approach warning (vehicle-to-vehicle distance control mode)

3034-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
■Automatic cancelation of constant speed control mode
Constant speed control mode is automatica lly canceled in the following situations:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●Pre-collision braking is activated.
If constant speed control mode is automati cally canceled for any other reason, there may
be a malfunction in the syst em. Contact any authorized Lexus retailer or Lexus autho- rized repairer, or an y reliable repairer.
■Warning messages and buzzers for dynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or to inform the driver of the need for ca ution while driving. If a warning message is shown on the
multi-information display, read the message and follow the instructions.
■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the brake pedal
when deceleration of the system is insuff icient or operate the accelerator pedal when
acceleration is required. As the sensor may not be able to correctly detect these types of vehicles, the approach
warning ( P. 300) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (trailers with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor