2012 TOYOTA PRIUS PLUS Owners Manual

297 2-4. Using other driving systems
2
When driving
PRIUS +_OM_OM47821E_(EE)
CAUTION
Handling the radar sensor
Observe the following to ensure the cruise control system can function effec-
tively.
Otherwise, the system may not function correctly and could result in an acci-
dent.
Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or
damage them.
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may become
inaccurate or malfunction. If the sensor or surrounding area is subject to a
strong impact, always have the area inspected and adjusted by any autho-
rized Toyota dealer or repairer, or another duly qualified and equipped pro-
fessional.
Do not disassemble the sensor.
Do not attach accessories or stickers to the sensor, grille cover or sur-
rounding area.
Do not modify or paint the sensor and grille cover.
Do not replace them with non-genuine parts.

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2-4. Using other driving systems
PRIUS +_OM_OM47821E_(EE)
Driving assist systems
To help enhance driving safety and performance, the following sys-
tems 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 vehicle.
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 spin-
ning 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

299 2-4. Using other driving systems
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When driving
PRIUS +_OM_OM47821E_(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
P. 304
PCS (Pre-Crash Safety System) (if equipped)
P. 307
Emergency brake signal (if equipped)
When the brakes are applied suddenly, the stop lights automati-
cally flash to alert the vehicle behind.

300 2-4. Using other driving systems
PRIUS +_OM_OM47821E_(EE)
When the TRC/VSC/ABS systems are operating
The slip indicator light will flash
while the TRC/VSC/ABS sys-
tems are operating.
Sounds and vibrations caused by the ABS, brake assist, VSC and TRC
A sound may be heard from the engine compartment when the hybrid
system is started, just after the vehicle begins to move, if the brake pedal
is depressed forcefully or repeatedly, or 1-2 minutes after the hybrid sys-
tem is stopped. 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 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.
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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When driving
PRIUS +_OM_OM47821E_(EE)
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. 478
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 opera-
tion.
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
braking operation.

302 2-4. Using other driving systems
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CAUTION
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 the vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you, especially in the fol-
lowing 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.
Do not drive the vehicle in conditions where stability and power may be lost.
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.

303 2-4. Using other driving systems
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When driving
PRIUS +_OM_OM47821E_(EE)
CAUTION
Replacing tires
Make sure that all tires are of the specified size and of the same 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 and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact any authorized Toyota dealer or repairer, or another duly qualified
and equipped professional 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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Hill-start assist control
Hill-start assist control operating conditions
The system operates in the following situations:
• The shift position is in a position other than P.
• The parking brake is not applied.
• The accelerator pedal is not depressed.
Hill-start assist control cannot be operated while the slip indicator light is
illuminated.
Hill-start assist control helps to prevent the vehicle from rolling
backwards when starting on an incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is acti-
vated. The slip indicator will
also start flashing.