2021 TOYOTA PRIUS horn

2123-4. Adjusting the steering wheel and mirrors
PRIUS_OM_OM47E09U_(U)
Steering wheel
Hold the steering wheel and
push the lever down.
Adjust to the ideal position by
moving the steering wheel hori-
zontally and vertically.
After adjustment, pull the lever up
to secure the steering wheel.
To sound the horn, press on or
close to the mark.
Adjustment procedure
1
2
Horn

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
WARNING
■Sensors
Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where
this may occur are listed below.
● There is dirt, snow or ice on the sensor. (Wiping the sensors w ill resolve
this problem.)
● The sensor is frozen. (Thawing the area will resolve this probl em.)
In especially cold weather, if a sensor is frozen, the screen m ay show an
abnormal display, or obstacles may not be detected.
● The sensor is covered in any way.
● In harsh sunlight or intense cold weather
● On an extremely bumpy road, on an incline, on gravel, or on grass
● The vicinity of the vehicle is noisy due to vehicle horns, moto rcycle
engines, air brakes of large vehicles, or other loud noises pro ducing ultra-
sonic waves.
● The sensor is splashed with water or drenched with heavy rain.
● The sensor is drenched with water on a flooded road.
● The vehicle is leaning considerably to one side.
● The vehicle is equipped with a fender pole or wireless antenna.
● The vehicle is approaching a tall or curved curb.
● The area directly under the bumpers is not detected.
● If obstacles draw too close to the sensor.
● The bumper or sensor receives a strong impact.
● A non-genuine Toyota suspension (lowered suspension etc.) is in stalled.
● There is another vehicle equipped with parking assist sensors i n the vicin-
ity.
● Towing eyelets are installed.
● A backlit license plate is installed.
In addition to the examples above, depending on the shape and c ondition of
obstacles, detection may not be possible, or the detection rang e may be
shortened.

PRIUS_OM_OM47E09U_(U)
3814-5. Using the driving support systems
4
Driving
■Situations when the system may operate even though there is no possi-
bility of a collision
In the following situations, the system may operate even though there is no
possibility of a collision.
● Environmental influence
• The vehicle is driven toward a banner or flag, a low-hanging branch or a
boom barrier (such as those used at railroad crossings, toll gates and
parking lots).
• There is an obstacle on the shoulder of the road (when the veh icle is
driven in a narrow tunnel, on a narrow bridge or on a narrow road)
• The vehicle is being parallel parked
• There is a rut or hole in the surface of the road
• When the vehicle is driven on a metal cover (grating), such as those used
for drainage ditches
• The vehicle is driven on a steep slope
• The sensor is covered by water on a flooded road
● Influence from the weather
• Ice, snow, dirt, etc., has adhered to the sensor (if removed, the system
returns to normal)
• Heavy rain or water strikes the vehicle
• In severe weather such as fog, snow or a sand storm
● Influence from other sonic waves
• An ultrasonic wave source is nearby, such as the horn or parki ng assist
sensors of another vehicle, a vehicle detector, a motorcycle en gine or the
air brake of a large vehicle
• Electronic components (such as a backlit license plate (especially fluo-
rescent types), fog lights, a fender pole or a wireless antenna ) are
installed near the sensors
• The vehicle is driven on a narrow
road
• The vehicle is driven on a gravel road or in an area with tall grass

PRIUS_OM_OM47E09U_(U)
3834-5. Using the driving support systems
4
Driving
●Influence from other sonic waves
• An ultrasonic wave source is nearby, such as the horn or parki ng assist
sensors of another vehicle, a vehicle detector, a motorcycle en gine or the
air brake of a large vehicle
• Electronic components (such as a backlit license plate (especially fluo- rescent types), fog lights, a fender pole or a wireless antenna ) are
installed near the sensors
● Changes in the vehicle
• When driving with the shift position in N
• The vehicle is tilted a large amount
• The height of the vehicle has drastically changed due to the c arried load
(the nose tilts up or down)
• The direction of the sensor has deviated due to a collision or other impact
■ Parking Support Brake function while the Simple Advanced Parkin g
Guidance System is operating
P. 388
■ When removing and instal ling the 12-volt battery
The system needs to be initialized.
The system can be initialized by driving the vehicle straight a head for 5 sec-
onds or more at a speed of approximately 22 mph (35 km/h) or hi gher.
■ When “PKSB Unavailable” is displayed on the multi-information display
and the PKSB OFF indicator flashes
●Ice, snow, dirt, etc., may have adhered to the sensor. If this occurs, remove
the ice, snow, dirt, etc., from the sensor to return the system to normal.
Also, a warning message may be displayed at low temperatures du e to ice
forming on the sensor, and the sensor may not detect obstacles. Once the
ice melts, the system will return to normal.
● If this message is shown even after removing dirt from the sensor, or shown
when the sensor was not dirty to begin with, have the vehicle i nspected at
your Toyota dealer.
● System initialization may not have been performed after removal and instal-
lation of the 12-volt battery. Perform system initialization.
■ When “PKSB Malfunction Visit Your Dealer” is displayed on the m ulti-
information display, the PKSB OFF indicator flashes and the buz zer
sounds
The system may not be operating properly. Have the vehicle inspected at
your Toyota dealer.

PRIUS_OM_OM47E09U_(U)
4194-5. Using the driving support systems
4
Driving
WARNING
●Observe the following precautions, as the sensors may stop func tioning
properly which may lead to an accident.
• Do not subject the sensor to strong shocks by hitting it, etc. The sen-
sors may not function properly.
• When using a high-pressure washer to wash the vehicle, do not spray
water directly on the sensors. Equipment may not function prope rly if
subjected to an impact from strong water pressure. If the vehic le
bumper strikes something, equipment may not operate properly du e to
a sensor malfunction. Have the vehicle inspected at your Toyota dealer.
● In the following situations, the sensors may not operate normally and may
lead to an accident. Drive carefully.
• Obstacles cannot be detected in the side areas until a scan of the side
areas is completed. ( P. 368)
• Even after the scan of the side areas is completed, obstacles such as other vehicles, people or animals that approach from the sides cannot
be detected.
• The sensor is frozen (if it thaws, the system returns to norma l).
A warning message may display at particularly low temperatures due to
the sensor freezing and it may not detect parked vehicles.
• The sensor is blocked by someone’s hand.
• The vehicle is tilted a large amount.
• The temperature is extremely hot or cold.
• The vehicle is driven on undulating roads, slopes, gravel road s, in areas
with tall grass, etc.
• An ultrasonic wave source is nearby, such as the horn or senso rs of
another vehicle, a motorcycle engine or the air brake of a larg e vehicle.
• Heavy rain or a water strikes the vehicle.
• The angle of the sensor may be deviated when assist control st arts
even if there is a parked vehicle in the target parking spot. Have the
vehicle inspected at your Toyota dealer.
• Do not install any accessories within the sensor detection ran ge.

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PRIUS_OM_OM47E09U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If the hybrid system will not start
One of the following may be the cause of the problem:
● The electronic key may no t be functioning properly.
* ( P. 647)
● There may not be sufficient f uel in the vehicle’s tank.
Refuel the vehicle. ( P. 90)
● There may be a malfunction in the immobilizer system.
* ( P. 9 5 )
● There may be a malfunction i n the shift control system.
*
(  P. 249, 609)
● The hybrid system may be malfunc tioning due to an electrical prob-
lem such as electronic key battery depletion or a blown fuse. H ow-
ever, depending on the type of malfunction, an interim measure is
available to start the hybrid system. ( P. 646)
● There is a possibility that the t emperature of the hybrid battery
(traction battery) is extremely low (approximately below -22°F
[-30°C]). ( P. 90, 248)
*: It may not be possible to shift the shift position other than P.
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( P. 650)
● The 12-volt battery terminal connections may be loose or corrod ed.
(  P. 524)
Reasons for the hybrid system not starting vary depending on
the situation. Check the followi ng and perform the appropriate
procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 245)
The interior lights and headlights are dim, or the horn does no t
sound or sounds at a low volume.

6467-2. Steps to take in an emergency
PRIUS_OM_OM47E09U_(U)
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( P. 650)
● One or both of the 12-volt battery terminals may be disconnecte d.
(  P. 524)
Contact your Toyota dealer if the problem cannot be repaired, o r if repair
procedures are unknown.
When the hybrid system does not start, the following steps can be
used as an interim measure to sta rt the hybrid system if the power
switch is functioning normally.
Do not use this starting procedur e except in cases of emergency.
Set the parking brake.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for about 15 seconds while
depressing the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the
system may be malfunctioning. Hav e the vehicle inspected by your
Toyota dealer.
The interior lights and headlights do not turn on, or the horn
does not sound.
Emergency start function
1
2
3

730Alphabetical index
PRIUS_OM_OM47E09U_(U)
Front turn signal lights ........... 261Replacing light bulbs............. 577
Turn signal lever ................... 261
Fuel ........................................... 675 Capacity ................................ 667
Fuel gauge ............................ 116
Information ............................ 675
Refueling............................... 283
Type ...................................... 667
Warning light ......................... 594
Fuel consumption............ 133, 170
Fuel filler door.......................... 283
Opener .................................. 285
Refueling............................... 283
When the fuel filler door cannot be opened............... 286
Fuses ........................................ 563
Garage door opener ................ 488
Glove box ................................. 462
Hands-free system (for
cellular phone)
*
Head restraints ........................ 209
Head-up display ....................... 158
Headlights ................................ 263 AHB (Automatic High Beam) ................................. 268
Headlight aim ................ 566, 716
Light switch ........................... 263
Replacing light bulbs............. 577
Heated steering wheel............. 456
Heaters Automatic air conditioning
system ....... ................. 436, 446
Heated steering wheel .......... 456
Outside rear view mirrors ........................ 440, 450
Seat heaters ......................... 456 High coolant temperature
warning light.......................... 594
High mounted stoplight Replacing.............................. 577
High-voltage components ........ 88
Hill-start assist control ........... 421
Hood ......................................... 515
Hooks
Cargo hooks ......................... 468
Coat hooks ........................... 486
Grocery bag hook ................. 469
Retaining hooks (floor mat) .... 26
Horn .......................................... 212
Hybrid battery (tr action battery)
Air intake vent ......................... 89
Location .................................. 88
Specification ......................... 667
Hybrid battery (traction battery) air intake vent............ 89 Cleaning ............................... 551
Hybrid system............................ 84 Brake Override System ........ 229
Drive-Start Control ................ 230
Emergency shut off system .... 89
Energy monitor/consumption
screen ................ 127, 165, 172
EV drive mode ...................... 252
High voltage components ....... 88
Hybrid System Indicator ....... 129
Hybrid system precautions ..... 88
Hybrid vehicle driving tips ..... 427
If the hybrid system will not start .................................... 645
Overheating .......................... 656
Power switch ........................ 245
Regenerative braking ............. 86
Starting the hybrid system .... 245
Vehicle proximity notification system .......... ..................... ... 85
Hybrid System Indicator ......... 129
Hybrid transmission................ 255
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