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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
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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
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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.
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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.
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4464-5. Using the driving support systems
PRIUS_OM_OM47F32E_(EE)■When a message related to AWD system is displayed on the multi-infor-
mation display (AWD models)
Perform the following actions.
MessageDetailsActions
“AWD System Over-
heated
Switching to 2WD
Mode”
AWD system is over-
heating.
Stop the vehicle for a
certain amount of time
or drive the vehicle at
approximately 10 km/h
(6 mph) or more to
reduce the overload to
the system. Once the
display message on the
multi-information dis-
play turns off, there is
no problem continuing
to drive.
“AWD System Over-
heated
2WD Mode Engaged”
The vehicle switched
from all-wheel drive
(AWD) to front wheel
drive due to overheat-
ing.
“AWD System Malfunc-
tion
2WD Mode Engaged
Visit Your Dealer”A malfunction occurred
in the AWD system,
and the vehicle
switched to front wheel
drive.
Have the vehicle
inspected by any
authorized Toyota
retailer or Toyota autho-
rized repairer, or any
reliable repairer imme-
diately.
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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.
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4534-6. Driving tips
4
Driving
PRIUS_OM_OM47F32E_(EE)
Accelerate the vehicle slowly, keep a safe distance between you and
the vehicle ahead, and drive at a reduced speed suitable to road con-
ditions.
Park the vehicle and shift the shift position to P and block the wheel
under the vehicle without setting the parking brake. The parking brake
may freeze up, preventing it from being released. If the vehicle is
parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle
to move unexpectedly, possibly leading to an accident.
Use the correct tire chain size when mounting the tire chains. Chain
size is regulated for each tire size.
Side chain
3.0 mm (0.12 in.)
30.0 mm (1.18 in.)
10.0 mm (0.39 in.)
Cross chain
4.0 mm (0.16 in.)
25.0 mm (0.98 in.)
14.0 mm (0.55 in.)
Regulations regarding the use of tire chains vary depending on loca-
tion and type of road. Always check local regulations before installing
chains.
When driving the vehicle
When parking the vehicle
Selecting tire chains
1
2
3
4
5
6
Regulations on the use of tire chains
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4544-6. Driving tips
PRIUS_OM_OM47F32E_(EE)
■Tire chain installation
Observe the following precautions when installing and removing chains:
● Install and remove tire chains in a safe location.
● Install tire chains on the front tires only. Do not install tire chains on the rear
tires.
● Install tire chains on front tires as tightly as possible. Retighten chains after
driving 0.5 - 1.0 km (1/4 - 1/2 mile).
● Install tire chains following the instructions provided with the tire chains.
WARNING
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehicle control and cause death or
serious injury.
● Use tires of the specified size.
● Maintain the recommended level of air pressure.
● Do not drive at speeds in excess of the speed limit or the speed limit spec-
ified for the snow tires being used.
● Use snow tires on all, not just some wheels.
■ Driving with tire chains
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in the vehicle being unable to be driven safely,
and may cause death or serious injury.
● Do not drive in excess of the speed limit specified for the tire chains being
used, or 50 km/h (30 mph), whichever is lower.
● Avoid driving on bumpy road surfaces or over potholes.
● Avoid sudden acceleration, abrupt steering, sudden braking and shifting
operations that cause sudden engine braking.
● Slow down sufficiently before entering a curve to ensure that vehicle con-
trol is maintained.
● Do not use LTA (Lane Tracing Assist) (if equipped).
■ When parking the vehicle
When parking the vehicle without applying the parking brake, make sure to
chock the wheels. If you do not chock the wheels, the vehicle may move
unexpectedly, possibly resulting in an accident.