2023 TOYOTA PRIUS ABS

441
4
4-5. Using the driving support systems
Driving
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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.
◆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.
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads
◆Active Cornering Assist (ACA)
Helps to prevent the vehicle from drifting to the outer side by per-
forming inner wheel brake control when attempting to accelerate
while turning
To keep driving safety and performance, the following systems
operate automatically in response to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too heavily when operating the vehi-
cle.

4424-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when start-
ing on an uphill
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆Emergency brake signal
When the brakes are applied suddenly, the emergency flashers
automatically flash to alert the vehicle behind.
◆E-Four (Electronic On-Demand AWD system) (AWD models)
Automatically switches from front-wheel drive to all-wheel drive
(AWD) according to the driving conditions, helping to ensure reli-
able handling and stability. Examples of conditions where the sys-
tem will switch to AWD are when cornering, going uphill, starting off
or accelerating, and when the road surface is slippery due to snow,
rain, etc.
The slip indicator light will flash
while the TRC/VSC/ABS systems
are operating.
When the TRC/VSC/ABS systems are operating

4444-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)■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
●No more than 2 seconds have elapsed after the brake pedal is released.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRC and
hill-start assist control systems
●A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, when the hybrid system is started or just after the
vehicle begins to move. This sound does not indicate that a malfunction has
occurred in any of these systems.
●Any of the following conditions may occur when the above systems are
operating. 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 also after the vehicle comes to a stop.
■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 one or two min-
utes passed after the stop of the hybrid system.
■Active Cornering Assist operation sounds and vibrations
When the Active Cornering Assist is operated, operation sounds and vibra-
tions may be generated from the brake system, but this is not a malfunction.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.

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.

4484-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)
WARNING
■When the TRC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road condi-
tions. As these are the systems to help ensure vehicle stability and driving
force, do not turn the TRC/VSC systems off unless necessary.
■ Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and
total load capacity. In addition, make sure that the tires are inflated to the
recommended tire inflation pressure level.
The ABS, TRC and VSC systems will not function correctly if different tires
are installed on the vehicle.
Contact any authorized Toyota retailer or Toyota authorized repairer, or any
reliable repairer for further information when replacing tires or wheels.
■ Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect
the driving assist systems, and may cause a system to malfunction.

5817-2. Steps to take in an emergency
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7
When trouble arises
Low engine oil pressure warning light
(warning buzzer)*2
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and con-
tact any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer.
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The emission control system (if equipped)
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
ABS warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
(Red/yellow)
Electric power steering system warning light (warning
buzzer)
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
Warning lightWarning light/Details/Actions

5827-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
(Flashes or illumi- nates)(If equipped)
PCS warning light
• When a buzzer sounds simultaneously:
Indicates a malfunction has occurred in the PCS (Pre-
Collision System).
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
• When a buzzer does not sound:
The PCS (Pre-Collision System) has become temporar-
ily unavailable, corrective action may be necessary.
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 294, 596)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
 P. 306
(Orange) (If equipped)
LTA indicator (warning buzzer)
Indicates a malfunction in the LTA (Lane Tracing Assist)
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 322)
Slip indicator light
Indicates a malfunction in:
• The VSC system;
• The TRC system; or
• The hill-start assist control system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
The light will flash when the ABS, VSC or TRC system is
operating.
Warning lightWarning light/Details/Actions

5917-2. Steps to take in an emergency
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7
When trouble arises
■Warning messages
The warning messages explained below may differ from the actual messages
according to operation conditions and vehicle specifications.
■ System warning lights
The master warning light does not come on or flash in the following cases.
Instead, a separate system warning light will come on along with a message
or image shown on the multi-information display.
● “Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( P. 581)
● “Braking Power Low Visit Your Dealer”:
The brake system warning light (yellow) will come on. ( P. 580)
● Indicates that a door is not fully closed while the vehicle is stopped.:
The Open door warning light comes on. ( P. 5 8 3 )
■ If “Visit Your Dealer” is shown
The system or part shown on the multi- information display is malfunctioning.
Have the vehicle inspected by any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer.