warning light TOYOTA PRIUS 2023 Service Manual

3064-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)• 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 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 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 VSC is disabled
●If VSC is disabled (P. 443), 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. • If the front of the vehicle is raised or
lowered

3084-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
WARNING
■Before using LTA system
● Do not rely solely upon the LTA system. The LTA system does not auto-
matically drive the vehicle or reduce the amount of attention that must be
paid to the area in front of the vehicle. The driver must always assume full
responsibility for driving safely by paying careful attention to the surround-
ing conditions and operating the steering wheel to correct the path of the
vehicle. Also, the driver must take adequate breaks when fatigued, such
as from driving for a long period of time.
● Failure to perform appropriate driving operations and pay careful attention
may lead to an accident, resulting in death or serious injury.
● When not using the LTA system, use the LTA switch to turn the system off.
■ Situations unsuitable for LTA system
In the following situations, use the LTA switch to turn the system off. Failure
to do so may lead to an accident, resulting in death or serious injury.
● Vehicle is driven on a road surface which is slippery due to rainy weather,
fallen snow, freezing, etc.
● Vehicle is driven on a snow-covered road.
● White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
● Vehicle is driven in a temporary lane or restricted lane due to construction
work.
● Vehicle is driven in a construction zone.
● A spare tire, tire chains, etc. are equipped.
● When the tires have been excessively worn, or when the tire inflation pres-
sure is low.
● During emergency towing.
■ Preventing LTA system malfunctions and operations performed by
mistake
● Do not modify the headlights or place stickers, etc. on the surface of the
lights.
● Do not modify the suspension etc. If the suspension etc. needs to be
replaced, contact any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.
● Do not install or place anything on the hood or grille. Also, do not install a
grille guard (bull bars, kangaroo bar, etc.).
● If your windshield needs repairs, contact any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.

3104-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
WARNING
●There are shadows on the road that run parallel with, or cover, the white
(yellow) lines.
● The vehicle is driven in an area without white (yellow) lines, such as in
front of a tollgate or checkpoint, or at an intersection, etc.
● The white (yellow) lines are cracked, “Raised pavement marker” or stones
are present.
● The white (yellow) lines cannot be seen or are difficult to see due to sand,
etc.
● The vehicle is driven on a road surface that is wet due to rain, puddles,
etc.
● The traffic lines are yellow (which may be more difficult to recognize than
lines that are white).
● The white (yellow) lines cross over a curb, etc.
● The vehicle is driven on a bright surface, such as concrete.
● If the edge of the road is not clear or straight.
● The vehicle is driven on a surface that is bright due to reflected light, etc.
●Vehicle is driven where the road
diverges, merges, etc.
● Repair marks of asphalt, white (yellow)
lines, etc. are present due to road
repair.

3114-5. Using the driving support systems
4
Driving
PRIUS_OM_OM47F32E_(EE)
WARNING
●The vehicle is driven in an area where the brightness changes suddenly,
such as at the entrances and exits of tunnels, etc.
● Light from the headlights of an oncoming vehicle, the sun, etc. enters the
camera.
● The vehicle is driven on a slope.
● The vehicle is driven on a road which tilts left or right, or a winding road.
● The vehicle is driven on an unpaved or rough road.
● The traffic lane is excessively narrow or wide.
● The vehicle is extremely tilted due to carrying heavy luggage or having
improper tire pressure.
● The distance to the preceding vehicle is extremely short.
● The vehicle is moving up and down a large amount due to road conditions
during driving (poor roads or road seams).
● When driving in a tunnel or at night with the headlights off or when a head-
light is dim due to its lens being dirty or it being misaligned.
● The vehicle is struck by a crosswind.
● The vehicle is affected by wind from a vehicle driven in a nearby lane.
● The vehicle has just changed lanes or crossed an intersection.
● Tires which differ by structure, manufacturer, brand or tread pattern are
used.
● When tires of a size other than specified are installed.
● Snow tires, etc. are equipped.
● The vehicle is being driven at extremely high speeds.

3344-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver.
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.
When the vehicle ahead of you stops, your vehicle will also stop (vehicle is
stopped by system control). After the vehicle ahead starts off, pushing the
cruise control lever up or depressing the accelerator pedal (start-off opera-
tion) will resume follow-up cruising. If the start-off operation is not per-
formed, system control continues to keep your vehicle stopped.
When the turn signal lever is operated and your vehicle moves to an over-
taking lane while driving at 80 km/h (50 mph) or more, the vehicle will
accelerate to help to overtake a passing vehicle.
The system’s identification of what is an overtaking lane may be deter-
mined solely based on the location of the steering wheel in the vehicle (left
side driver position versus right side driver position.) If the vehicle is driven
to a region where the overtaking lane is on a different side from where the
vehicle is normally driven, the vehicle may accelerate when the turn signal
lever is operated in the opposite direction to the overtaking lane (e.g., if the
driver normally operates the vehicle in a region where the overtaking lane
is to the right but then drives to a region where the overtaking lane is to the
left, the vehicle may accelerate when the right turn signal is activated).
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

3714-5. Using the driving support systems
4
Driving
PRIUS_OM_OM47F32E_(EE)
WARNING
■To ensure the system can operate properly
● Keep the sensor and its surrounding area on the bumper clean at all times.
● Do not subject a sensor or its surrounding area on the rear bumper to a
strong impact.
If a sensor is moved even slightly off position, the system may malfunction
and vehicles may not be detected correctly.
In the following situations, have your vehicle inspected by any authorized
Toyota retailer or Toyota authorized repairer, or any reliable repairer.
• A sensor or its surrounding area is subject to a strong impact.
• If the surrounding area of a sensor is scratched or dented, or part of
them has become disconnected.
● Do not disassemble the sensor.
● Do not attach accessories or stickers to the sensor or surrounding area on
the bumper.
● Do not modify the sensor or surrounding area on the bumper.
● Do not paint the rear bumper any color other than an official Toyota color.
One Blind Spot Monitor sensor is
installed inside the left and right side of
the vehicle rear bumper respectively.
Observe the following to ensure the Blind
Spot Monitor can function correctly.

3924-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
WARNING
■Cautions regarding the use of the system
There is a limit to the degree of recognition accuracy and control perfor-
mance that this system can provide, do not overly rely on this system. The
driver is always responsible for paying attention to the vehicle’s surround-
ings and driving safely.
■ To ensure the system can operate properly
Observe the following precautions to avoid an unexpected accident.
● Do not damage the sensors, and always keep them clean.
● Do not attach a sticker or install an electronic component, such as a backlit
license plate (especially fluorescent type), fog lights, fender pole or wire-
less antenna near a radar sensor.
● Do not subject the surrounding area of the sensor to a strong impact. If
subjected to an impact, have the vehicle inspected by any authorized
Toyota retailer or Toyota authorized repai rer, or any reliable repairer. If the
front or rear bumper needs to be removed/installed or replaced, contact
any authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
● Do not modify, disassemble or paint the sensors.
● Do not attach a license plate cover.
● Keep your tires properly inflated.
■ When to disable the function
In the following situations, disable the function as it may operate even
though there is no possibility of a collision.
● Failing to observe the warnings above.
● A non-genuine Toyota suspension (lowered suspension, etc.) is installed.
■ Side sensors
In the following situations, the Toyota parking assist-sensor may not operate
normally and may result in an unexpected accident. Drive carefully.
● Obstacles may not be detected in the side areas until the vehicle is driven
for a short time and a scan of the side areas is completed. ( P. 388)
● Even after the scan of the side areas is completed, obstacles such as
other vehicles, people or animals that approach from the sides cannot be
detected.
● Even after the scan of the side areas is completed, obstacles may not be
detected depending on the surrounding situation of the vehicle.
At that time, the side sensor operation displays ( P. 382) temporary turn
off.

4434-5. Using the driving support systems
4
Driving
PRIUS_OM_OM47F32E_(EE)
If the vehicle gets stuck in mud, dirt or snow, the TRC system may
reduce power from the hybrid system to the wheels. Pressing
to turn the system off may make it easier for you to rock the vehicle in
order to free it.
To turn the TRC system off,
quickly press and release
.
The “Traction Control Turned Off”
will be shown on the multi-informa-
tion display.
Press again to turn the sys-
tem back on.
■ Turning off both TRC and VSC systems
To turn the TRC and VSC systems off, press and hold for more than 3
seconds while the vehicle is stopped.
The VSC OFF indicator will come on and the “Traction Control Turned Off”
will be shown on the multi-information display.*
Press again to turn the systems back on.
*: On vehicles with pre-collision system, pre-collision brake assist and pre-
collision braking will also be disabled. The PCS warning light will come on
and the message will be shown on the multi-information display. ( P. 582)
■ When the message is displayed on the multi-information display show-
ing that TRC has been disable d even if has not been pressed
TRC is temporary deactivated. If the information continues to show, contact
any authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
Disabling the TRC system

4454-5. Using the driving support systems
4
Driving
PRIUS_OM_OM47F32E_(EE)■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically
re-enabled in the following situations:
●When the power switch is turned off
●If only the TRC system is turned off, the TRC will turn on when vehicle
speed increases
If both the TRC and VSC systems are turned off, automatic re-enabling will
not occur when vehicle speed increases.
■Operating conditions of Active Cornering Assist
The system operates when the following occurs.
●TRC/VSC can operate
●The driver is attempting to accelerate while turning
●The system detects that the vehicle is drifting to the outer side
●The brake pedal is released
■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. 581
■Operating conditions of emergency brake signal
When the following conditions are met, the emergency brake signal will oper-
ate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The system judges from the vehicle deceleration that it is a sudden braking
operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will be canceled in any of the following situa-
tions:
●The emergency flashers are turned on.
●The system judges from the vehicle deceleration that is not a sudden brak-
ing operation.

4474-5. Using the driving support systems
4
Driving
PRIUS_OM_OM47F32E_(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 roads.
■ Stopping distance when the ABS is operating may exceed that of nor-
mal conditions
The ABS is not designed to shorten the 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/VSC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRC/VSC system is operating. Drive the
vehicle carefully in conditions where stability and power may be lost.
■ Active Cornering Assist does not operate effectively when
● Do not overly rely on Active Cornering Assist. Active Cornering Assist may
not operate effectively when accelerating down slopes or driving on slip-
pery road surfaces.
● When Active Cornering Assist frequently operates, Active Cornering
Assist may temporarily stop operating to ensure proper operation of the
brakes, TRC and VSC.
■ Hill-start assist control does not operate effectively when
● Do not overly rely on hill-start assist control. 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 TRC/ABS/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.