TOYOTA PRIUS 2012 3.G Owners Manual

291
2-4. Using other
driving systems
2
When driving
■No-handed driving warning
If the steering wheel is not operated for about 15 seconds on a straight road
or about 5 seconds on a curve, the buzzer will beep twice, indicators on the
multi-information display will flash, and the lane keeping assist function will
be temporarily canceled. If you drive the vehicle with your hands lightly
touching the steering wheel, this may also be detected as no-handed driv-
ing.
■ When the vehicle has been parked in the sun
The LKA system functions may not be available for a while after driving has
started. In such cases, turn the LKA system off and turn it on again after nor-
mal temperature returns. When the temperature in the cabin decreases and
the temperature around the camera sensor becomes suitable for its opera-
tion, the functions will begin to operate.
■ Warning lights and warning messages for LKA
Warning lights and messages are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. ( P. 496, 510)
CAUTION
■Before using the LKA system
Do not rely on the LKA system to remain within a selected lane. The LKA
system is not designed to enable inattentive driving. The steering wheel
should be operated by the driver to mainta in the vehicle in a suitable position
within its lane. Always drive carefully.

292 2-4. Using other driving systems
CAUTION
■Turn the LKA off while driving in any of the following conditions
Do not use LKA in any of the following situations.
Otherwise, the system may not function correctly and could result in an acci-
dent.
● When driving with snow tires, snow chains, a spare tire, or similar equip-
ment.
● When driving with non-standard parts or aftermarket equipment installed.
(including modified tires and suspensions, etc.)
● When there are objects or structures along the roadside that might be mis-
interpreted as lane markers. (such as guardrails, curb, reflector posts, etc.)
● When there are wheel ruts, icy trademar ks, etc. or if snow remains on the
road surface.
● When there are shadows on the road r unning parallel with lane markers,
or if a shadow covers the lane markers.
● When there are visible lines on the pavement from road repairs, or if the
remains of old lane markers are still visible on the road.
● When driving on slippery roads, such as those covered with rain, ice or
snow.
● When driving in a lane other than the driving or passing lanes on a freeway
or highway.
● When driving on a road with lane closures due to maintenance, or when
driving in a temporary lane.
● When driving on winding roads or roads that are rough or uneven.

293
2-4. Using other
driving systems
2
When driving
NOTICE
■In the following situations, the LKA will not work, or will not perform
reliably:
● When lane markers are interrupted or are not present, such as before a
tollbooth.
● When lane markers are only on one side of the road.
● When driving on a sharp curve.
● When lanes are extremely narrow or extremely wide.
● When the vehicle leans to one side an unusual amount due to a heavy
load or improper tire inflation pressure.
● When the following distance between your vehicle and the vehicle ahead
is extremely short.
● When the lane markers are broken, “Botts’ dots”, or “Raised pavement
marker”.
● When lane markers are obscured or partially obscured by sand, dirt, etc.
● When driving on a particularly bright road surface, such as concrete.
● When driving on a road surface that is bright due to reflected light.

294 2-4. Using other driving systems
NOTICE
●When driving in a location where the light level changes rapidly, such as
the entrance to or exit from a tunnel.
● When sunlight or the headlights of oncoming vehicles are shining directly
into the camera lens.
● When driving on roads that are branching or merging.
● When pavement lane markers are difficult to see due to rain, snow, fog,
etc.
● When driving on a road surface that is wet due to rain, previous rainfall,
standing water, etc.
● When the vehicle experiences strong up-and-down motion such as when
driving on an extremely rough road or on a seam in the pavement.
● When headlight brightness is reduced due to dirt on the lenses, or when
the headlights are misaligned.
● When driving with a strong crosswind.

295
2-4. Using other
driving systems
2
When driving
NOTICE
■Camera sensor
●Keep the windshield clean at all times.
LKA performance may deteriorate due to the presence of raindrops, con-
densation, ice or snow on the windshield.
● Do not attach a sticker or other items to the windshield near the camera
sensor.
● When adjusting the rear view mirror, make sure that it does not block the
camera lens.
● When it is cold, using the heater with air blowing to the feet may allow the
upper part of the windshield to fog up. This will have a negative effect on
the images. In such a case, use the windshield defogger to provide warm,
dry air to the windshield.
● Do not place anything on the dashboard.
The camera sensor may recognize the image reflected on the windshield
as lane markings by mistake.
● Do not scratch the camera lens, or let it get dirty.
● Do not change the installation position of the camera sensor or remove it.
The direction of the camera sensor is precisely adjusted.
● Do not subject the camera sensor to strong impact or force, and do not
disassemble the camera sensor.
Observe the following to ensure that the
LKA system functions correctly.
ITO24P134

296
2-4. Using other driving systems
Driving assist systems
To help enhance driving safety and performance, the following sys-
tems operate automatically in res ponse to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too h eavily 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
■TRAC (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
■Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road
surfaces by controlling steering performance.

297
2-4. Using other
driving systems
2
When driving
When the TRAC/VSC/ABS systems are operating
The slip indicator light will flash
while the TRAC/VSC/ABS sys-
tems are operating.
■Hill-start assist control
P. 301
■PCS (Pre-Collision System) (if equipped)
P. 303

298 2-4. Using other driving systems
■Sounds and vibrations caused by the ABS, brake assist, VSC and
TRAC
● 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.
■ 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. 501

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2-4. Using other
driving systems
2
When driving
CAUTION
■The ABS does not opera te effectively when
● Tires with inadequate gripping ability are used (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 in the following situ-
ations:
● 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
■ TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRAC 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.

300 2-4. Using other driving systems
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 your Toyota dealer 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.