2013 TOYOTA PRIUS malfunction

270 2-4. Using other driving systems
PRIUS_OM_OM47791U_(U)
■Cruise control can be set when
● The shift position is in D.
● Vehicle speed is above approximately 25 mph (40 km/h).
■ Accelerating after setting the vehicle speed
● The vehicle can be accelerated normally. After acceleration, the set
speed resumes.
● Even without canceling the cruise control, the set speed can be
increased by first accelerating the vehicle to the desired speed and then
pushing the lever down to set the new speed.
■ Automatic cruise control cancelation
Cruise control will stop maintaining the vehicle speed in any of the following
situations.
● Actual vehicle speed falls more than approximately 10 mph (16 km/h)
below the preset vehicle speed.
At this time, the memorized set speed is not retained.
● Actual vehicle speed is below approximately 25 mph (40 km/h).
● Enhanced VSC is activated.
■ If the cruise control indicator light flashes
Press the “ON-OFF” button once to deactivate the system, and then press
the button again to reactivate the system.
If the cruise control speed cannot be set or if the cruise control cancels
immediately after being activated, there may be a malfunction in the cruise
control system. Have the vehicle inspected by your Toyota dealer.

282 2-4. Using other driving systems
PRIUS_OM_OM47791U_(U)
■Automatic cancelation of vehicle-to-vehicle distance control
Vehicle-to-vehicle distance control driving is automatically canceled in the
following situations:
● Actual vehicle speed falls below approximately 25 mph (40 km/h).
● Enhanced VSC is activated.
● The sensor cannot operate correctly because it is covered in some way.
● The windshield wipers are operating at high speed (when the wiper
switch is set to the high speed windshield wiper operation position).
If vehicle-to-vehicle distance control driving is automatically canceled for any
other reason, there may be a malfunction in the system. Contact your Toyota
dealer.
■ Automatic cancelation of constant speed control
The cruise control will stop maintaining the vehicle speed in the following sit-
uations:
● Actual vehicle speed is more than approximately 10 mph (16 km/h)
below the set vehicle speed.
At this time, the memorized set speed is not retained.
● Vehicle speed falls below appr oximately 25 mph (40 km/h).
● Enhanced VSC is activated.

283
2-4. Using other
driving systems
PRIUS_OM_OM47791U_(U)
2
When driving
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-t\
o-
vehicle distance control operates properly. (Some obstructions, such as
snow, ice and plastic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control (vehicle-to-vehicle distance control mode) will
be canceled if dirt is detected. (Constant speed control mode can be used).
■ Warning lights, messages and buzzers for dynamic radar cruise con-
trol
Warning lights, warning messages and buzzers are used to indicate a sys-
tem malfunction or to inform the driver of the need for caution while driving.
Grille cover
Radar sensor

288 2-4. Using other driving systems
PRIUS_OM_OM47791U_(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.

295
2-4. Using other
driving systems
PRIUS_OM_OM47791U_(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

296 2-4. Using other driving systems
PRIUS_OM_OM47791U_(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)

302 2-4. Using other driving systems
PRIUS_OM_OM47791U_(U)
■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.
*: 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 warning light (warning buzzer)
 P. 507

304 2-4. Using other driving systems
PRIUS_OM_OM47791U_(U)
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.