Page 328 of 688

328 2-4. Using other driving systems
PRIUS PHV_OM_OM47856U_(U)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles
are in front of you.
As the sensor may not be able to correctly detect these types of vehicles,
the approach warning ( P. 321) will not be activated, and a fatal or serious
accident may result.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving
● Vehicles with small rear ends (trailers with no load on board etc.)
● Motorcycles traveling in the same lane
■ Conditions  under  which  the  vehicle -to-vehicle  distance  control  may
not function correctly
Apply the brakes as necessary in the following conditions as the radar sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
● When water or snow thrown up by the surrounding vehicles hinders the
functioning of the sensor
● When your vehicle is pointing upwards (caused by a heavy load in the lug-
gage compartment etc.)
● When the road curves or when the lanes are narrow
● When steering wheel operation or your  position in the lane is unstable
● When the vehicle ahead of you decelerates suddenly 
         
        
        
     
        
        Page 329 of 688
329
2-4. Using other 
driving systems
PRIUS PHV_OM_OM47856U_(U)
2
When driving
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 Toy-
ota 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 337 of 688

337
2-4. Using other driving systems
PRIUS PHV_OM_OM47856U_(U)
2
When driving
PCS (Pre-Collision System)
: If equipped
When  the  radar  sensor  detects  possibility  of  a  frontal  collision,  the
pre-collision systems such as the  brakes and seat belts are automat-
ically engaged to lessen impact as well as vehicle damage.
■ Pre-collision seat belts (front seat belts only)
If the pre-collision sensor detects that a collision is unavoidable, the
pre-collision system will retract the seat belt before the collision occurs.
The same will happen if the driver  makes an emergency braking or
loses control of the vehicle. ( P. 162)
However, when the VSC system is disabled, the system will not oper-
ate in the event of skidding.
■ Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
■Pre-collision braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automat-
ically applied to reduce the collision speed. Pre-collision braking can be
disabled using the pre-collision braking off switch. 
         
        
        
     
        
        Page 338 of 688
338 2-4. Using other driving systems
PRIUS PHV_OM_OM47856U_(U)
Disabling pre-collision brakingPre-collision braking enabled
Pre-collision braking disabled
The “PCS” warning light will
turn on when pre-collision
braking is disabled.
Radar sensorThe radar sensor detects vehi-
cles or other obstacles on or
near the road ahead and deter-
mines whether a collision is
imminent based on the position,
speed, and heading of the obsta-
cles. 
         
        
        
     
        
        Page 341 of 688

341
2-4. Using other 
driving systems
PRIUS PHV_OM_OM47856U_(U)
2
When driving
■Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may
also be occasions when the sensor cannot detect pedestrians, animals,
bicycles, motorcycles, trees, or snowdrifts. 
■ Situations in which the pre-collis ion system does not function properly
The system may not function effectively in situations such as the following:
● On roads with sharp bends or uneven surfaces
● If a vehicle suddenly moves in front of your vehicle, such as at an inter-
section
● If a vehicle suddenly cuts in front of your vehicle, such as when overtak-
ing
● In inclement weather such as heavy rain, fog, snow or sand storms
● When your vehicle is skidding with the VSC system off
● When an extreme change in vehicle height occurs
● When the axis of the radar is out of adjustment
■ Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in
the sensors being unable to detect obstacles, the pre-collision system will be
automatically disabled. In this case, the system will not activate even if there
is a collision possibility.
■ When  there  is  a  malfunction  in  the  system,  or  if  th e  system  is  tempo-
rarily unusable
Warning lights and/or warning messages will turn on or flash. ( P. 538, 550) 
         
        
        
     
        
        Page 344 of 688

344 2-4. Using other driving systems
PRIUS PHV_OM_OM47856U_(U)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary in any of the following situations.
●When water or snow thrown up by the surrounding vehicles hinders the
functioning of the sensor
● When your vehicle is pointing upwards (caused by a heavy load in the lug-
gage compartment etc.)
● Vehicles that cut in suddenly
● Vehicles with small rear ends (trailers with no load on board etc.)
● Motorcycles traveling in the same lane
■ Handling the radar sensor
Observe the following to ensure the pre-collision system can function effec-
tively:
●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 Toy-
ota 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. 
         
        
        
     
        
        Page 506 of 688
506 4-3. Do-it-yourself maintenance
PRIUS PHV_OM_OM47856U_(U)
FUSEAmpereCircuit
14 STOP 10A Stop lights, high mounted stop-
light, brake system, driver support 
system, vehicle proximity notifica-
tion system
15 P FR DOOR 25A Power windows
16 D FR DOOR 25A Power windows
17 DOOR RR 25A Power windows
18 DOOR RL 25A Power windows
19 S/ROOF 30A No circuit
20 ECU-IG NO.1 10A Electric cooling fans, multiplex 
communication system, vehicle 
proximity notification system
21 ECU-IG NO.2 10A Driver support system, Pre-Colli-
sion System, inside rear view mir-
ror, garage door opener, yaw rate 
& G sensor, brake system, naviga-
tion system, tire pressure warning 
system, seat belt pretensioners, 
audio system, emergency flash-
ers, turn signal lights, windshield 
wipers, headlight cleaner
22 GAUGE 10AHeadlight leveling system, gauges 
and meters
23 A/C 10AAir conditioning system, Remote 
Air Conditioning System
24 WASHER 15A Windshield washer 
         
        
        
     
        
        Page 507 of 688
507
4-3. Do-it-yourself maintenance
PRIUS PHV_OM_OM47856U_(U)
4
Maintenance and care
FUSEAmpereCircuit
25 RR WIP 20A Rear window wiper and washer
26 WIP 30A Windshield wipers
27 MET 7.5A Gauges and meters
28 IGN 10ABrake system, driver support sys-
tem, multiport fuel injection sys-
tem/sequential multiport fuel 
injection system, SRS airbag sys-
tem, front passenger occupant 
classification system (ECU and 
sensors), power management sys-
tem, smart key system, front pas-
senger’s seat belt reminder light
29 PANEL 10AAir conditioning system, personal 
light, transmission, P position 
switch, navigation system, Remote 
Air Conditioning System, headlight 
cleaner, front passenger’s seat 
belt reminder light, headlight level-
ing system, glove box light, clock, 
audio system, MPH or km/h switch
30 TAIL 10AHeadlight leveling system, park-
ing lights, tail lights, license plate 
lights, front fog lights, side marker 
lights