Page 244 of 588

2444-5. Using the driving support systems
PRIUS c_U (OM52F96U)
■High beam automatic turning on or off conditions
●When all of the following conditions are fulfilled, the high beam will be auto-
matically turned on (after approximately 1 second):
• Vehicle speed is approximately 21 mph (33 km/h) or more.
• The area ahead of the vehicle is dark.
• There are no vehicles ahead with headlights or tail lights turned on.
• There are few streetlights on the road ahead.
● If any of the following conditions is met, the high beams will turn off automat-
ically:
• Vehicle speed is below approx imately 17 mph (27 km/h).
• The area ahead of the vehicle is not dark.
• Vehicles ahead have their headlights or tail lights turned on.
• There are many streetlights on the road ahead.
■ Front sensor detection information
●The high beam may not be automatically turned off in the following situa-
tions:
• When vehicles ahead suddenly appear from a curve
• When the vehicle is cut in front of by another vehicle
• When vehicles ahead are hidden from sight due to repeated curves, road
dividers or roadside trees
• When vehicles ahead appear from the faraway lane on wide road
• When vehicles ahead have no lights
● The high beam may be turned off if a vehicle ahead that is using fog lights
without using the headlights is detected.
● House lights, street lights, traffic signals, and illuminated billboards or signs
may cause the high beam to switch to the low beams, or the low beams to
remain on.
● The following factors may affect the amount of time taken to turn the high
beam on or off:
• The brightness of headlights, fog lights, and tail lights of vehicles ahead
• The movement and direction of vehicles ahead
• When a vehicle ahead only has operational lights on one side
• When a vehicle ahead is a two-wheeled vehicle
• The condition of the road (gradient, curve, condition of the road surface,
etc.)
• The number of passengers and amount of luggage
● The high beam may be turned on or off when the driver does not expect it.
● Bicycles or similar objects may not be detected. 
         
        
        
     
        
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2454-5. Using the driving support systems
4
Driving
PRIUS c_U (OM52F96U)●
In the situations shown below, the system may not be able to accurately
detect surrounding brightness levels. This may cause the low beams to
remain on or the high beams to cause problems for pedestrians, vehicles
ahead or other parties. In these cases, manually switch between the high
and low beams.
• In bad weather (rain, snow, fog, sandstorms, etc.)
• The windshield is obscured by fog, mist, ice, dirt, etc.
• The windshield is cracked or damaged.
• The front sensor is deformed or dirty.
• The front sensor temperature is extremely high.
• Surrounding brightness levels are equal to those of headlights, tail lights
or fog lights.
• Vehicles ahead have headlights or tail lights that are either switched off,
dirty, are changing color, or are not aimed properly.
• When driving through an area of in termittently changing brightness and
darkness.
• When frequently and repeatedly driving ascending/descending roads, or roads with rough, bumpy or uneven surfaces (such as stone-paved
roads, gravel tracks, etc.).
• When frequently and repeatedly taking curves or driving on a winding road.
• There is a highly reflective object ahead of the vehicle, such as a sign or
a mirror.
• The back of a vehicle ahead is highly reflective, such as a container on a truck.
• The vehicle’s headlights are damaged or dirty, or are not aimed properly.
• The vehicle is listing or titling due to a  flat tire, a trailer being towed, etc.
• The high beam and low beam are repeatedly being switched between in an abnormal manner.
• The driver believes that the high beam may be causing problems or dis-
tress to other drivers or pedestrians nearby. 
         
        
        
     
        
        Page 246 of 588

2464-5. Using the driving support systems
PRIUS c_U (OM52F96U)■
Temporarily lowering sensor sensitivity
The sensitivity of the sensor can be temporarily lowered.
Vehicles without a smart key system: Turn the engine switch off while the
following conditions are met.
Vehicles with a smart key system: Turn the “POWER” switch off while the
following conditions are met
• The headlight switch is in  .
• The headlight switch lever is in high beam position.
• Automatic High Beam switch is on.
Vehicles without a smart key system: Turn the engine switch to the “ON”
position.
Vehicles with a smart key system: Turn the “POWER” switch to ON mode.
Within 60 seconds after  , repeat pulling the headlight switch lever to the
original position then pushing it to the high beam position quickly 10 times,
then leave the lever in high beam position.
If the sensitivity is changed, the Automatic High Beam indicator is turn on
and off 3 times.
Automatic High Beam (headlights) may turn on even the vehicle is stopped.
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        Page 458 of 588

4587-3. Do-it-yourself maintenance
PRIUS c_U (OM52F96U)■
License plate light
Remove the cover.
Insert a properly sized screw-
driver into the hole of the cover,
and pry off the cover as shown
in the illustration.
To prevent damaging the vehi-
cle, wrap the tip of the screw-
driver with tape.
Remove the light bulb.
When installing, reverse the steps listed.
■Lights other than the above
If any of the lights listed below  has burnt out, have it replaced by
your Toyota dealer.
● Headlight low/high beam/daytime running lights
● Front fog lights (if equipped)
● Side turn signal lights
● Stop/tail lights
● High mounted stoplight
■LED light bulbs
The headlight low/high beam/daytime running lights, front fog lights (if
equipped), stop/tail lights and high mounted stoplight consist of a number of
LEDs. If any of the LEDs burn out, take your vehicle to your Toyota dealer to
have the light replaced.
■ Condensation build-up on the inside of the lens
Temporary condensation build-up on the inside of the headlight lens does not
indicate a malfunction. Contact your Toyota dealer for more information in the
following situations:
●Large drops of water have built up on the inside of the lens.
● Water has built up inside the headlight.
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        Page 484 of 588

4848-2. Steps to take in an emergency
PRIUS c_U (OM52F96U)
(If equipped)
Indicates a malfunction in:
• The Automatic High Beam system (if equipped)
• The LED headlight system (if equipped)A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
(If equipped)
Indicates that:
• There is a high possibility of a frontal collision;
or
• The pre-collision braking function is operating A buzzer also sounds.
 Check the vehicle's surroundings and take
evasive action if necessary.
(If equipped)
• Indicates a malfunction in the smart key system
• Indicates a malfunction in the steering lock sys-
tem
A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
(If equipped)
Indicates a malfunction in the cruise control sys-
tem
A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
Indicates a malfunction in the Brake Override
System
A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
Warning messageDetails/Actions
(Flashes) 
         
        
        
     
        
        Page 487 of 588

4878-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52F96U)
(If equipped)
Indicates that the Automatic High Beam switch is
pressed while the headlights are in low beam.
Turn the high beam on.
(If equipped)
Indicates that, since the VSC (Vehicle Stability
Control) system was turned off, the pre-collision
brake system operation is stopped
Turn the VSC on. ( P. 262)
(If equipped)
Indicates that the pre-collision system is disabled.
Have the vehicle inspected by your Toyota
dealer.
Indicates that the hybrid battery (traction battery)
is low A buzzer also sounds.
 When stopping the vehicle for a long
period of time, shift the shift lever to P. The
hybrid battery (traction battery) cannot be
charged with the shift position in N.
Indicates that the hybrid battery (traction battery)
power has dropped because a long period of time
has elapsed after shifting the shift lever to N A buzzer also sounds.
 Shift the shift lever to P and restart the
hybrid system when starting the vehicle.
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes) 
         
        
        
     
        
        Page 489 of 588

4898-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U (OM52F96U)Indicates that the TRAC (Traction Control) sys-
tem has been deactivated
Turn the TRAC on. ( P. 262)
Indicates that the accelerator and brake pedals
are being depressed simultaneously, and the
Brake Override System is operating. ( P. 167)
 Release the accelerator or brake pedal.
Indicates that the shift lever is shifted while the
accelerator pedal is being depressed
A buzzer also sounds.
 Release the accelerator pedal.
(If equipped)
The system is temporarily canceled because the
operating conditions of the front sensor (tempera-
ture, etc.) are not met.
The following systems may be suspended: 
• PCS (Pre-Collision system) (if equipped)
• LDA (Lane Departure Alert) (if equipped)
• Automatic High Beam (if equipped)
The system can be operated when the
operating conditions  of the front sensor
(temperature, etc.) are met. Turn the system
off, wait for a while, and then turn the sys-
tem back on.
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes) 
         
        
        
     
        
        Page 490 of 588

4908-2. Steps to take in an emergency
PRIUS c_U (OM52F96U)
*1: Refer to the separate “Scheduled Maintenance Guide” or “Owner’s ManualSupplement” for the maintenance interval applicable to your vehicle.
*2: For the EV drive mode operating conditions:P. 194
Carrying out the corresponding ac tion turns the message off.
(If equipped)
The area of the windshield in front of the front
sensor is fogged up or covered with dirt, rain, ice,
snow, etc.
The following systems may be suspended: 
• PCS (Pre-Collision system) (if equipped)
• LDA (Lane Departure Alert) (if equipped)
• Automatic High Beam (if equipped)
Turn the system off, clear the windshield of
dirt, fog, ice, etc. then turn the system back
on. ( P. 222)
(If equipped)
Indicates that the LDA (Lane Departure Alert)
system cannot be used because the vehicle
speed is lower than approximately 32 mph (50
km/h)
 Drive the vehicle at 32 mph (50 km/h) or
higher.
(If equipped)
Indicates that the LDA (Lane Departure Alert)
system is suspended (The vehicle speed is too
high for the system to operate.)
Reduce the vehicle speed.
Other displayed message
Displayed messageDetails/Actions
Maintenance of the hybrid battery (traction battery)
cooling component is required
The filter may be clogged, the air intake vent
may be blocked or there may be a gap in the
duct.
 Have maintenance performed on the hybrid
battery (traction batter y) cooling component
at your Toyota dealer.
Warning messageDetails/Actions
(Flashes)