brake TOYOTA PRIUS PLUS 2019 Service Manual

2774-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47D30E_(EE)
■Operational conditions
The pre-crash safety system is enabled and the system determines that the
possibility of a frontal collision with a vehicle or pedestrian is high.
Each function is operational at the following speeds:
●Pre-crash warning:
• Vehicle speed is between approximately 10 and 180 km/h (7 and
110 mph). (For detecting a pedestrian, vehicle speed is between approxi-
mately 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-crash brake assist:
• Vehicle speed is between approximately 30 and 180 km/h (20 and
110 mph). (For detecting a pedestrian, vehicle speed is between approxi-
mately 30 and 80 km/h [20 and 50 mph].)
• The relative speed between your vehicle and the vehicle or pedestrian
ahead is approximately 30 km/h (20 mph) or more.
●Pre-crash braking:
• Vehicle speed is between approximately 10 and 180 km/h (7 and
110 mph). (For detecting a pedestrian, vehicle speed is between approxi-
mately 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 vehicle has not been driven for a certain amount of time
●If the shift position is in R
●If VSC is disabled (only the pre-crash warning function will be operational)
■Pedestrian detection function
■Cancelation of the pre-crash braking
If either of the following occur while the pre-crash braking function is operat-
ing, it will be canceled:
●The accelerator pedal is depressed strongly.
●The steering wheel is turned sharply or abruptly. The pre-crash safety system detects
pedestrians based on the size, profile,
and motion of a detected object. However,
a pedestrian may not be detected
depending on the surrounding brightness
and the motion, posture, and angle of the
detected object, preventing the system
from operating properly. (P. 282)

2814-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47D30E_(EE)• When driving in inclement weather such as heavy rain, fog, snow or a
sandstorm
• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes sud-
denly, such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of oncoming
traffic, shines directly into the camera sensor
• When the surrounding area is dim, such as at dawn or dusk, or while at
night or in a tunnel
• 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 camera sensor is misaligned
●In some situations such as the following, sufficient braking force 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 slippery sur-
face • If the front of the vehicle is raised or
lowered

3034-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47D30E_(EE)
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-vehicle dis-
tance switch.
Example of deceleration cruising 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 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 warning warns you when the system cannot decelerate suffi-
ciently 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 constant speed cruising.
1
2
3

3074-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47D30E_(EE)
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.
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 may not occur even when the
vehicle-to-vehicle distance is small.
●When the speed of the preceding vehicle matches or exceeds
your vehicle speed
●When the preceding vehicle is traveling at an extremely slow
speed
●Immediately after the cruise control speed was set
●When depressing the accelerator pedal
Canceling and resuming the speed control
1
2
Approach warning (vehicle-to-vehicle distance control mode)

3104-5. Using the driving support systems
PRIUS +_OM_OM47D30E_(EE)■Automatic cancelation of constant speed control mode
Constant speed control mode is automatically canceled in the following situa-
tions:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below
the set vehicle speed.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●Pre-crash braking is activated.
If constant speed control mode is automatically canceled for any other rea-
son, there may be a malfunction in the system. Contact any authorized
Toyota retailer or Toyota authorized repairer, or any reliable repairer.
■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 be heard.
This does not indicate a malfunction.
■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 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 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 insufficient 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. 307) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane

3124-5. Using the driving support systems
PRIUS +_OM_OM47D30E_(EE)■Conditions under which the vehicle-to-vehicle distance control mode
may not function correctly
In the case of the following conditions, operate the brake pedal (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 the 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

3144-5. Using the driving support systems
PRIUS +_OM_OM47D30E_(EE)
To change the set speed, operate the lever until the desired set speed
is obtained.
Increases the speed
Decreases the speed
Fine adjustment: Momentarily
move the lever in the desired direc-
tion.
Large adjustment: Hold the lever in
the desired direction.
The set speed will be increased or decreased as follows:
Fine adjustment: By approximately 1 km/h (0.6 mph) or 1 mph (1.6 km/h)
each time the lever is operated
Large adjustment: The set speed can be increased or decreased continu-
ally until the lever is released.
Pulling the lever toward you
cancels the constant speed
control.
The speed setting is also canceled
when the brakes are applied.
Pushing the lever up resumes
the constant speed control.
Resuming is available when the
vehicle speed is more than approx-
imately 40 km/h (25 mph).
Adjusting the set speed
1
2
Canceling and resuming the constant speed control
1
2

3184-5. Using the driving support systems
PRIUS +_OM_OM47D30E_(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.

3194-5. Using the driving support systems
4
Driving
PRIUS +_OM_OM47D30E_(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
◆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

3204-5. Using the driving support systems
PRIUS +_OM_OM47D30E_(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. 445