brake sensor TOYOTA 4RUNNER 2021 Owners Manual (in English)

2284-3. Operating the lights and wipers
4RUNNER (U)
■Daytime running light system
●Vehicles with a headlight high beam/daytime running lights: The daytime
running lights illuminate using the same lights as the headligh t high beam
and illuminate dimmer than the headlight high beam.
● 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 engine is running
• The parking brake is released
• The headlight switch is in the , (type A only),
* (type B
and C) 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.
Type A and B: Daytime running lights can be turned off by opera ting 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)
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.

2544-5. Using the driving support systems
4RUNNER (U)
◆Pre-collision warning
When the system determines
that the possibility of a frontal
collision is high, a buzzer will
sound and a warning 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 possibility of a frontal colli-
sion is high, the system applies greater braking force in relat ion to
how strongly the brake pedal is depressed.
◆Pre-collision braking
When the system determines that the possibility of a frontal colli-
sion is high, the system warns the driver. If the system determ ines
that the possibility of a frontal collision is extremely high, the brakes
are automatically applied to hel p avoid the collision or reduce the
collision speed.
PCS (Pre-Collision System)
The pre-collision system uses a radar sensor and front camera
to detect vehicles and pedestrians in front of your vehicle. Wh en
the system determines that the possibility of a frontal collisi on
with a vehicle or pedestrian i s high, a warning operates to urg e
the driver to take evasive action and the potential brake pres-
sure is increased to help the driver avoid the collision. If the sys-
tem determines that the possibi lity of a frontal collision with a
vehicle or pedestrian is extremely high, the brakes are automat i-
cally applied to hel p avoid the collision or help reduce the
impact of the collision.
The pre-collision system can b e disabled/enabled and the warnin g
timing can be changed. ( P. 2 5 7 )

2634-5. Using the driving support systems
4
Driving
4RUNNER (U)●
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
● Some pedestrians such as the following may not be detected by t he radar
sensor and front camera, preventing the system from operating p roperly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approx-
imately 6.5 ft. (2 m)
• Pedestrians wearing oversized clothing (a rain coat, long skir t, etc.), mak-
ing their silhouette 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 vehi-
cle
• 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 (manhole 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 objec t
• Pedestrians who are extremely close to the side of the vehicle (outside
rear view mirror, etc.)
■ If VSC is disabled
●If VSC is disabled ( P. 322, 323), the pre-collision brake assist and pre-col-
lision 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.

2764-5. Using the driving support systems
4RUNNER (U)
This mode employs a radar sensor to detect the presence of vehi cles
up to approximately 320 ft. (100 m) ahead, determines the curre nt
vehicle-to-vehicle following distance, and operates to maintain a suit-
able 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 distance can also be set by operating the vehicle-to-ve hicle dis-
tance switch.
Example of deceleration crui sing 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
decelerates your vehicle. When a greater reduction in vehicle s peed 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 warning warns you when the system cannot decelerate su ffi-
ciently to prevent your vehicle fr om 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 syst em then
returns to constant speed cruising.
Driving in vehicle-to-vehi cle distance control mode
1
2
3

2834-5. Using the driving support systems
4
Driving
4RUNNER (U)■
Automatic cancelation of c onstant speed control mode
Constant speed control mode is automatically canceled in the following situa-
tions:
● Actual vehicle speed is more than approximately 10 mph (16 km/h ) below
the set vehicle speed.
● Actual vehicle speed falls below approximately 25 mph (40 km/h) .
● VSC is activated.
● TRAC is activated for a period of time.
● When the VSC or TRAC system is turned off.
● Pre-collision braking is activated.
If constant speed control mode is automatically canceled for an y other rea-
son, there may be a malfunction in the system. Contact your Toyota dealer.
■ Brake system operation sound
If the brakes are applied automatically while the vehicle is in vehicle-to-vehi-
cle distance control mode, a brake system operation sound may b e heard.
This does not indicate a malfunction.
■ Warning messages and buzzers for d ynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution 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 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. 280) 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

2844-5. Using the driving support systems
4RUNNER (U)●
When water or snow thrown up by the surrounding vehicles hinders the
detecting of the sensor
■ 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 your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
● Preceding vehicle has an extremely
high ground clearance
●When the road curves or when the
lanes are narrow
● When steering wheel operation or your
position in the lane is unstable

2894-5. Using the driving support systems
4
Driving
4RUNNER (U)
■Intuitive parking assist can be operated when
●Front corner sensors:
• The engine switch is in the “ON” position (without a smart key system) or
the engine switch is in IGNITION ON mode (with a smart key syst em).
• The shift lever is in a position other than P.
• The vehicle speed is less than approximately 6 mph (10 km/h).
● Rear corner and rear center sensors:
• The engine switch is in the “ON” position (without a smart key system) or
the engine switch is in IGNITION ON mode (with a smart key syst em).
• The shift lever is in R.
■ Intuitive parking assist display
When an obstacle is detected while the Toyota parking assist mo nitor is in
use, the warning indicator will appear in the upper part of the screen even if
the display setting has been set to off.
■ Sensor detection information
●The sensor’s detection areas are limited to the areas around th e vehicle’s
front corner and rear bumpers.
● 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 will resolve
this problem.)
• The sensor is frozen. (Thawing the area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen ma y show an
abnormal display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on gr ass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle
engines, air brakes of large vehicles, or other loud noises pro ducing ultra-
sonic 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 eyelet is 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 Toyota suspension (lowered suspension etc.) is i nstalled.
• People may not be detected if they are wearing certain types o f clothing.
In addition to the examples above, there are instances in which, because of
their shape, signs and other objects may be judged by the senso r to be
closer than they are.

2914-5. Using the driving support systems
4
Driving
4RUNNER (U)
WARNING
■When using the intuitive parking assist
Observe the following precautions.
Failing to do so may result in the vehicle being unable to be d riven safely
and possibly cause an accident.
● Do not use the sensor at speeds in excess 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.
NOTICE
■When using intuitive parking assist-sensor
In the following situations, the system may not function correctly due to a
sensor malfunction etc. Have the vehicle checked by your Toyota dealer.
● The intuitive parking assist operation display flashes, and a beep sounds
when no obstacles are detected.
● If the area around a sensor collides with something, or is subjected to
strong impact.
● If the bumper collides with something.
● If the display shows continuously without a beep.
● If a display error occurs, first check the sensor.
If the error occurs even if there is no ice, snow or mud on the sensor, it is
likely that the sensor is malfunctioning.
■ Notes when washing the vehicle
Do not apply intensive bursts of water or steam to the sensor a rea.
Doing so may result in the sensor malfunctioning.

4797-2. Steps to take in an emergency
7
When trouble arises
4RUNNER (U)
*1: Parking brake engaged warning buzzer:A buzzer will sound if the vehicle is driven at a speed of appr oximately 3
mph (5 km/h) or more.
*2: Open door warning buzzer: The open door warning buzzer sounds to alert one or more of the doors is
not fully closed (with the vehicle having reached a speed of 3 mph [5 km/h]).
*3: Driver’s seat belt buzzer:
The driver's seat belt warning buzzer sounds to alert the drive r that his or
her seat belt is not fastened. Once the engine switch is turned to ON, the
buzzer sounds. If the seat belt is still unfastened, the buzzer sounds inter-
mittently for a certain period of time after the vehicle reache s a certain
speed.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front
passenger that his or her seat belt is not fastened. If the sea t belt is unfas-
tened, the buzzer sounds intermittently for a certain period of time after the
vehicle reaches a certain speed.
*4: This light illuminates on the multi-information display.
■ SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors (front door), side impact sensors (rear), safing
sensor (rear), driver's seat belt buckle switch, front passenger occupant clas-
sification system (ECU and sensors), “AIR BAG ON” and “AIR BAG OFF”
indicator lights, front passenger's seat belt buckle switch, se at belt preten-
sioners, airbags, interconnecting wiring and power sources. (P. 3 5 )
■ Key reminder buzzer (vehicles without a smart key system)
The buzzer indicates that the key has not been removed with the engine off
and the driver’s door opened.
■ Open moon roof reminder buzzer (if equipped)
The buzzer indicates that the moon roof is not fully closed with the engine off
and the driver’s door opened.
■ Front passenger detection senso r, passenger seat belt reminder and
warning buzzer
● If luggage is placed on the front passenger seat, the front pas senger detec-
tion sensor may cause the warning light to flash and the warnin g buzzer to
sound even if a passenger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passenger,
and the warning light may not operate properly.

577What to do if... (Troubleshooting)
4RUNNER (U)
●The seat belt reminder light is flashing
Are the driver and the front passenger wearing the seat belts?
(P. 477)
●The brake system warning light is on
Is the parking brake released? ( P. 224)
●The open door warning indicator is on
Are all the doors closed? (P. 110, 131)
Depending on the situation, other types of warning buzzer may a lso sound.
( P. 474, 484)

●Did anyone inside the vehicle open a door during setting the al arm?
The sensor detects it and the alarm sounds. ( P. 79)
To stop the alarm, turn the engine switch to IGNITION ON mode ( vehicles
with a smart key system) or start the engine.
●Is the electronic key left inside the vehicle?
Check the message on the multi-information display.
●When a warning light turns on, refer to P. 474.
●When a warning light turns on or a warning message or indicator is dis-
played, refer to P. 474, 484.
A warning buzzer sounds during driving
An alarm is activated and the horn sounds
A warning buzzer sounds w hen leaving the vehicle
(vehicles with a smart key system)
A warning light turns on or a warning message is displayed