2021 TOYOTA PRIUS brake sensor

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PRIUS_OM_OM47E09U_(U)
4-3. Operating the lights and wipers
■Daytime running light system
●The daytime running lights illuminate using the same lights as the head-
lights, and illuminate dimmer than the headlights.
● To make your vehicle more visible to other drivers during dayti me driving,
the daytime running lights turn on automatically when all of the following
conditions are met. (The daytime running lights are not designe d for use at
night.)
• The hybrid system is operating
• The parking brake is released
• The headlight switch is in the , , or
* position
*: When the surroundings are bright
The daytime running lights remain on after they illuminate, eve n if the park-
ing brake is set again.
● For the U.S.A.: Daytime running lights can be turned off by ope rating the
switch.
● Compared to turning on the headlights, the daytime running ligh t system
offers greater durability and consumes less electricity, so it can help improve
fuel economy.
■ Headlight control sensor (if equipped)
■ Automatic light off system
●When the headlights come on: The headlights and tail lights tur n off 30 sec-
onds after a door is opened and closed if the power switch is t urned to
ACCESSORY mode or turned off. (The lights turn off immediately if on
the key is pressed after all the doors are locked.)
● When only the tail lights come on: The tail lights turn off automatically if the
power switch is turned to ACCESSORY mode or turned off and the driver’s
door is opened.
To turn the lights on again, turn the power switch to ON mode, or turn the light
switch to the , , or position once and then back to the
or position.
The sensor may not function properly if an
object is placed on the sensor, or anything
that blocks the sensor is affixed to the
windshield.
Doing so interferes with the sensor
detecting the level of ambient light and
may cause the automatic headlight sys-
tem to malfunction.
Air conditioning operation may also be
interrupted.

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
PCS (Pre-Collision System)
The system can detect the following:
●Vehicles
● Bicyclists
● Pedestrians
: If equipped
The pre-collision system uses a radar sensor and front camera
to detect objects ( P. 296) in front of the vehicle. When the sys-
tem determines that the possibility of a frontal collision with an
object is high, a warning operates to urge the driver to take e va-
sive action and the potential brake pressure is increased to he lp
the driver avoid the collision. If the system determines that t he
possibility of a frontal collision with an object is extremely high,
the brakes are automatically applied to help avoid the collisio n
or help reduce the impa ct of the collision.
The pre-collision system can b e disabled/enabled and the warnin g
timing can be changed. ( P. 3 0 0 )
Detectable objects

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
• If the wheels are misaligned
• If a wiper blade is blocking the front camera
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the radar sensor or front camera is misaligned
● In some situations such as the following, sufficient braking fo rce 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 sli ppery sur-
face
■ If VSC is disabled
●If VSC is disabled ( P. 422), 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-Coll ision Brake
System Unavailable” will be displayed on the multi-information display.
• If the front of the vehicle is raised or
lowered

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■Dynamic radar cruise control wi th full-speed range can be set when
● The shift position is in D.
● The desired set speed can be set when the vehicle speed is approximately
20 mph (30 km/h) or more.
(However, when the vehicle speed is set while driving at below approxi-
mately 20 mph [30 km/h], the set speed will be set to approxima tely 20 mph
[30 km/h].)
■ Accelerating after setting the vehicle speed
The vehicle can accelerate by operating the accelerator pedal. After acceler-
ating, the set speed resumes. However, during vehicle-to-vehicl e distance
control mode, the vehicle speed may decrease below the set spee d in order
to maintain the distance to the preceding vehicle.
■ When the vehicle stops while follow-up cruising
●Pushing the lever up while the vehicle ahead stops will resume follow-up
cruising if the vehicle ahead starts off within approximately 3 seconds after
the lever is pushed up.
● If the vehicle ahead starts off within 3 seconds after your veh icle stops, fol-
low-up cruising will be resumed.
■ Automatic cancelation of vehicle-to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically cance led in the fol-
lowing situations.
● VSC is activated.
● TRAC is activated for a period of time.
● When the VSC or TRAC system is turned off.
● The sensor cannot detect correctly because it is covered in some way.
● Pre-collision braking is activated.
● The parking brake is operated.
● The vehicle is stopped by system control on a steep incline.
● The following are detected when the vehicle has been stopped by system
control:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes.
In this situation, the shift position may automatically switch to P. (P. 258)
If vehicle-to-vehicle distance control mode is automatically ca nceled for any
reasons other than the above, there may be a malfunction in the system.
Contact your Toyota dealer.

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■When the sensor may not be correctly detect ing the vehicle ahead
In the case of the following and depending on the conditions, o perate the
brake pedal when deceleration of the system is insufficient or operate the
accelerator pedal when acceleration is required.
As the sensor may not be able to correctly detect these types o f vehicles, the
approach warning ( P. 336) 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
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
● Preceding vehicle has an extremely high
ground clearance

PRIUS_OM_OM47E09U_(U)
3414-5. Using the driving support systems
4
Driving
■Conditions under which the vehic le-to-vehicle distance control mode
may not function correctly
In the case of the following conditions, operate the brake peda l (or accelera-
tor pedal, depending on the situation) as necessary.
As the sensor may not be able to correctly detect vehicles ahead, the system
may not operate properly.
● When the vehicle ahead of you decelerates suddenly
● When driving on a road surrounded by a structure, such as in a tunnel or on
a bridge
● While the vehicle speed is decreasing to the set speed after th e vehicle
accelerates by depressing the accelerator pedal
●
When the road curves or when the lanes
are narrow
● When steering wheel operation or your
position in the lane is unstable

PRIUS_OM_OM47E09U_(U)
3694-5. Using the driving support systems
4
Driving
WARNING
■When using intuitive parking assist
Observe the following precautions to avoid an unexpected accident.
● Do not exceed the speed limit of 6 mph (10 km/h).
● The sensors’ detection areas and reaction times are limited. When moving
forward or reversing, check the areas surrounding the vehicle ( especially
the sides of the vehicle) for safety, and drive slowly, using t he brake to
control the vehicle’s speed.
● Do not install accessories within the sensors’ detection areas.

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4-5. Using the driving support systems
WARNING
■Sensors
Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where
this may occur are listed below.
● There is dirt, snow or ice on the sensor. (Wiping the sensors w ill resolve
this problem.)
● The sensor is frozen. (Thawing the area will resolve this probl em.)
In especially cold weather, if a sensor is frozen, the screen m ay show an
abnormal display, or obstacles may not be detected.
● The sensor is covered in any way.
● In harsh sunlight or intense cold weather
● On an extremely bumpy road, on an incline, on gravel, or on grass
● The vicinity of the vehicle is noisy due to vehicle horns, moto rcycle
engines, air brakes of large vehicles, or other loud noises pro ducing ultra-
sonic waves.
● The sensor is splashed with water or drenched with heavy rain.
● The sensor is drenched with water on a flooded road.
● The vehicle is leaning considerably to one side.
● The vehicle is equipped with a fender pole or wireless antenna.
● The vehicle is approaching a tall or curved curb.
● The area directly under the bumpers is not detected.
● If obstacles draw too close to the sensor.
● The bumper or sensor receives a strong impact.
● A non-genuine Toyota suspension (lowered suspension etc.) is in stalled.
● There is another vehicle equipped with parking assist sensors i n the vicin-
ity.
● Towing eyelets are installed.
● A backlit license plate is installed.
In addition to the examples above, depending on the shape and c ondition of
obstacles, detection may not be possible, or the detection rang e may be
shortened.