brake TOYOTA PRIUS PLUS 2017 Service Manual

2524-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
WARNING
■ Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
●Except on highways or expressways
● In heavy traffic
● On roads with sharp bends
● On winding roads
● On slippery roads, such as those covered with rain, ice or snow
● On steep downhills, or where ther e are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
● At entrances to expressways
● When weather conditions are bad enough that they may prevent the sen-
sors from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
● When an approach warning buzzer is heard often
■ When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes (or accelerator pedal) as necessary when any of the fol-
lowing types of vehicles are in front of you.
As the sensor may not be able to correctly detect these types of vehicles,
the approach warning ( →P. 246) will not be activated, and a fatal or serious
accident may result.
● 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

2534-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47B24E_(EE)
WARNING
■ Conditions under which the vehicle-to-vehicle distance control may
not function correctly
Apply the brakes (or accelerator pedal) as necessary in the following condi-
tions as the radar sensor may not be able to correctly detect vehicles
ahead, and a fatal or serious accident may result:
●When the vehicle ahead of you decelerates suddenly
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
●When the road curves or when the
lanes are narrow
● When steering wheel operation or your
position in the lane is unstable
Accelerate
Accelerate
Decelerate

2564-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corre-
sponding to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly,
or if the brakes are applied while driving on a slippery road surface
◆Brake assist
Generates an increased level of braking force after the brake pedal
is depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
To help enhance driving safety and performance, the following
systems operate automatically in response to various driving
situations. Be aware, however, that these systems are supple-
mentary and should not be relied upon too heavily when operat-
ing the vehicle.

2574-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47B24E_(EE)
◆VSC + (Vehicle Stability Control +)
Provides cooperative control of the ABS, TRC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery
road surfaces by controlling steering performance.
◆Hill-start assist control
Helps to prevent the vehicle from rolling backward when starting on
an incline or slippery slope
◆PCS (Pre-Crash Safety system) (if equipped)
→P. 2 6 2
◆Emergency brake signal
When the brakes are applied suddenly, the emergency flashers
automatically flash to alert the vehicle behind.
The slip indicator light will flash
while the VSC/TRC/ABS systems
are operating.
When the VSC/TRC/ABS systems are operating

2584-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRC and
hill-start assist control systems
Any of the following conditions may occur when the above systems are oper-
ating. 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 slightly after the ABS is activated.
● The brake pedal may move down slightly after the ABS is activated.
■ ECB operating sound
ECB operating sound may be heard 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 operated.
● 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 1-2 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 normal within 10 minutes.
■ Electric power steering system warning light (warning buzzer)
→ P. 388

2594-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47B24E_(EE)■
Operating conditions of emergency brake signal
When the following three conditions are met, the emergency brake signal will
operate:
●The emergency flashers are off.
● Actual vehicle speed is over 55 km/h (35 mph).
● The brake pedal is depressed in a manner that cause the system to judge
from the vehicle deceleration that this is a sudden braking operation.
■ Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off in any of the following situations:
●The emergency flashers are turned on.
● The brake pedal is released.
● The system judges from the vehicle deceleration that is not a sudden brak-
ing operation.
■ Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will
operate:
●The shift position 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:
● Shift the shift position to P or N
● The accelerator pedal is depressed
● The parking brake is engaged.
● Approximately 2 seconds elapse after the brake pedal is released.

2604-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
WARNING
■ 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 operating may exceed that of nor-
mal conditions
The ABS is not designed to shorten t he 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
■ TRC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRC 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 control to hold the vehicle on an incline, as doing so may
lead to an accident.
■ When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator light flashes.

2624-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
PCS (Pre-Crash Safety system)∗
◆Pre-crash warning
When a high possibility of a
frontal collision is detected, a
buzzer sounds and a message
is shown on the multi-informa-
tion display to urge the driver to
take evasive action.
◆Pre-crash brake assist
When there is a high possibility of a frontal collision, the system
applies greater braking force in relation to how strongly the brake
pedal is depressed.
◆Pre-crash braking
When there is a high possibility of a frontal collision, the system
warns the driver using a warning display and buzzer. If the system
determines that a collision is unavoidable, the brakes are automati-
cally applied to reduce the collision speed.
∗: If equipped
When the radar sensor detects possibility of a frontal collision,
brakes are automatically engaged to lessen impact as well as
vehicle damage.The alert timing for the pre-crash safety system can be changed or
turned ON/OFF, as necessary, by operating the switch. ( →P. 263)

2644-5. Using the driving support systems
PRIUS +_OM_OM47B24E_(EE)
The radar sensor detects vehi-
cles or other obstacles on or near
the road ahead and determines
whether a collision is imminent
based on the position, speed, and
heading of the obstacles.
■The pre-crash safety system is operational when
The pre-crash safety system is on ( →P. 263) and the following conditions are
met:
● Pre-crash warning:
• Vehicle speed is greater than about 15 km/h (10 mph).
• The speed at which your vehicle is approaching the obstacle or the vehi-
cle running ahead of you is greater than about 10 km/h (7 mph).
● Pre-crash brake assist:
• Vehicle speed is greater than about 30 km/h (19 mph).
• The speed at which your vehicle is approaching the obstacle or the vehi-
cle running ahead of you is greater than about 30 km/h (19 mph).
• The brake pedal is depressed.
● Pre-crash braking:
• Vehicle speed is greater than about 15 km/h (10 mph).
• The speed at which your vehicle is approaching the obstacle or the vehi-
cle running ahead of you is greater than about 10 km/h (7 mph).
Radar sensor

2654-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47B24E_(EE)■
Conditions that may trigger the system even if there is no possibility of a
collision
In any of the following situations wher e the frontal area of the radar sensor is
interrupted, the radar sensor may detect possibility of a frontal collision and
the system may be activated.
● When passing by an oncoming vehicle in a curve or turn to the right or the
left
● When rapidly approaching an obstacle ahead (e.g. preceding vehicle, toll
gate barrier, etc.)
● When there is a structural object (billboard, low ceiling, fluorescent light,
etc.) above the uphill road ahead
● When driving on a narrow road or th rough under a low overhead structure
(bridge, tunnel, fly-under, etc.)
● When driving on an uneven road surface
● When there is a metal object, bump, or protrusion on the road surface
● When vehicle’s front part is raised or lowered depending on loading condi-
tions
● When the direction of radar sensor is misaligned by strong impact applied
on an area around the radar sensor, etc.
● When there is an obstacle (guard rail, etc.) by the roadside at the entrance
to a curve
● When the front of your vehicle is pointing upwards (cause by putting a heavy
load in the luggage compartment etc.)
● When driving through an area filled with steam or smoke
When the system is activated in the situations described above, there is also
a possibility that the brakes may be applied with a force greater than normal.
■ Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may
also be occasions when the sensor cannot detect pedestrians, animals, bicy-
cles, motorcycles, trees, or snowdrifts.