Page 288 of 640
288 2-4. Using other driving systems
PRIUS_OM_OM47857U_DVD_(U)
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 your
Toyota dealer.
● 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.
Page 290 of 640

290 2-4. Using other driving systems
PRIUS_OM_OM47857U_DVD_(U)
Functions included in the LKALane departure warning function
If the system judges th at the vehicle may deviate from its lane, it
alerts the driver using beeping, screen displays and a sensory
warning
* given via the steering wheel.
*: A slight steering torque is applied for a short period of time in the direc- tion of the center of the lane.
Lane keeping assist function
• This function will be active wh en the vehicle-to-vehicle distance
control mode of the cruise control ( P. 272) is set with vehicle
speed above approximately 45 mph (72 km/h) and while the
lane departure warning function is active.
• When the lane keeping assist function is active, a slight steering torque will be applied, to help the driver maintain the vehicle
inside the lane.
The lane keeping assist function will be temporarily canceled if the steer-
ing wheel is not operated, or if you continue driving with your hands
lightly touching the steering wheel. ( P. 294)
Page 295 of 640

295
2-4. Using other
driving systems
PRIUS_OM_OM47857U_DVD_(U)
2
When driving
■No-handed driving warning
If the steering wheel is not operated for approximately 15 seconds on a
straight road or approximately 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 driving.
■ After the vehicle has been parked in the sun
The LKA system functions may not be available and a warning message
(P. 520) will be displayed for a while after driving has started. In such
cases, turn the LKA system off and turn it on again after normal temperature
returns. When the temperature in the cabin decreases and the temperature
around the camera sensor ( P. 289) becomes suitable for its operation, the
functions will begin to operate.
■ If there are lane markers on only one side of the vehicle
The lane keeping assist function will not operate. Also, the lane departure
warning will not operate for the side on which lane markers could not be rec-
ognized.
■ Conditions in which the function may not operate correctly
In the following conditions, the LKA system functions may not operate, or it
may not be possible to ensure adequate performance. Also, the camera
sensor may be unable to recognize lane lines causing the lane departure
warning function to operate incorrectly, or the lane keeping assist function
may not operate properly. However, this does not indicate a malfunction.
●When driving through an area with no lane markers, such as a tollbooth,
a crossing or before a ticket checkpoint
● 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
Page 296 of 640

296 2-4. Using other driving systems
PRIUS_OM_OM47857U_DVD_(U)
●When the lane markers are yellow (These may be more difficult for the
system to recognize compared to white markers.)
● When the lane markers are broken, “Botts’ dots”, “Raised pavement
marker” or stones
● When lane markers are obscured or partially obscured by sand, dirt, etc.
● When there are shadows on the road running parallel with lane markers,
or if a shadow covers the lane markers
● When driving on a particularly bright road surface, such as concrete
● When driving on a road surface that is bright due to reflected light
● 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 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 at nighttime is reduced due to dirt on the
lenses, or when the headlights are misaligned
● When driving with a strong crosswind
● When driving on winding roads or roads that are uneven
● When driving on rough or unpaved roads
■ When changing the tires
Depending on the tires used, sufficient performance may not be maintain-
able.
■ Warning messages for LKA
Warning messages are used to indicate a system malfunction or to inform
the driver of the need for caution while driving. (P. 516, 520)
Page 298 of 640

298 2-4. Using other driving systems
PRIUS_OM_OM47857U_DVD_(U)
NOTICE
■To prevent damage to or incorr ect operation of the LKA system
● Do not modify the headlights or attach stickers to the surface of the lights.
● Do not modify the suspension or sun visor, or replace them with non-genu-
ine parts.
● Do not install or place anything on the hood or the grille. Also, do not install
a grille guard (bull bars, kangaroo bar etc.).
● Do not modify the sun visor or replace it with anything other than a genu-
ine Toyota product.
● If your windshield needs repairs, contact your Toyota dealer.
■ Camera sensor (P. 289)
Observe the following to ensure that the LKA system functions correctly.
●Keep the windshield clean at all times.
Performance could be affected if the windshield is dirty, or if raindrops,
condensation or ice are adhering to the windshield.
● When adjusting the rear view mirror, make sure that it does not block the
camera lens.
● Do not attach window tinting to the windshield.
● Do not install an antenna in front of the camera lens.
● If the windshield is fogged up, use the windshield defogger to remove fog
from the windshield.
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.
●Do not attach a sticker or other items to
the windshield near the camera sensor.
● Do not install or place anything near the
camera.
Page 301 of 640
301
2-4. Using other
driving systems
PRIUS_OM_OM47857U_DVD_(U)
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. 305
■PCS (Pre-Collision System) (if equipped)
P. 307
Page 302 of 640

302 2-4. Using other driving systems
PRIUS_OM_OM47857U_DVD_(U)
■Sounds and vibrati ons 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.
*: If the LKA (Lane-Keeping Assist) system (if equipped) cannot operate in this case, a warning message will be shown on the multi-information dis-
play.
■ Electric power steering system wa rning light (warning buzzer)
P. 507
Page 303 of 640

303
2-4. Using other
driving systems
PRIUS_OM_OM47857U_DVD_(U)
2
When driving
CAUTION
■The ABS does not opera te 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
■ 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.
Drive the vehicle carefully 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.