Page 496 of 596
4968-2. Steps to take in an emergency
PRIUS c_U
Carrying out the corresponding action turns the message off.
After  taking  the  specified  steps  to  correct  the  suspected  probl em,
check that the warning m essage and light go off.
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.
 If  the  air  intake  vent  is  dirty,  refer  to  P.  402
for cleaning the air intake vent.
 If the message is being displayed and the air
intake  vent  is  not  dirty,  have  the  vehicle
inspected at your Toyota dealer.
Have  the  malfunction  repaired  immediately.  (vehicles  with  a
smart key system)
Interior
buzzerExterior buzzerWarning messageDetails/Actions
Once  The  electronic  key  is  not
detected  when  an  attempt  is
made  to  start  the  hybrid  sys-
tem.
Start  the  hybrid  system
with  the  electronic  key
present.
(Flashes) 
     
        
        Page 497 of 596
4978-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
Once3 times
The  electronic  key  was  carried
outside  the  vehicle  and  the
driver’s  door  was  opened  and
closed  while  the  shift  lever  was
in  P  without  turning  off  the
power switch. 
Turn the power switch off
or  bring  the  electronic  key
back into the vehicle.
The  electronic  key  was  carried
outside  the  vehicle  and  a  door
other than the driver's door was
opened  and  closed  while  the
power  switch  was  in  a  mode
other than off.
Bring  the  electronic  key
back into the vehicle.
Once
Contin-
uous 
(For 5  sec-
onds)
An  attempt  was  made  to  lock
the  doors  using  the  entry  func-
tion after the electronic key was
carried outside the vehicle with-
out turning off the power switch.
 Turn the power switch off
and lock the doors again.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes)
(Displayed alternately)
(Flashes) 
     
        
        Page 498 of 596
4988-2. Steps to take in an emergency
PRIUS c_U
9 times
An  attempt  was  made  to  start
the  hybrid  system  without  the
electronic key being present, or
the electronic key was not func-
tioning normally.
An  attempt  was  made  to  drive
when  the  regular  key  was  not
inside the vehicle.
Confirm  that  the  elec-
tronic  key  is  inside  the
vehicle.
Contin-
uous
The  driver’s  door  was  opened
while a shift lever position other
than  P  was  selected  without
turning off the power switch.
 Shift the shift lever to P.
Contin-
uousContin-uous
The  electronic  key  was  carried
outside  the  vehicle  and  the
driver’s  door  was  opened  and
closed  while  a  shift  lever  posi-
tion  other  than  P  was  selected
without  turning  off  the  power
switch.
 Shift the shift lever to P.
 Bring  the  electronic  key
back into the vehicle.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes)
(Flashes)
(Displayed alternately)
(Flashes) 
     
        
        Page 499 of 596

4998-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
Contin-uous 
(5 sec-
onds)
An  attempt  was  made  to  lock
the  doors  using  the  smart  key
system  while  the  electronic  key
was still inside the vehicle.
 Retrieve  the  electronic  key
from the vehicle and lock
the doors again.
Once
Contin-
uous 
(5 sec- onds)
An  attempt  was  made  to  lock
either  front  door  by  opening  a
door and putting the inside door
lock  button  into  the  lock  posi-
tion,  and  then  closing  the  door
while  pulling  on  the  outside
door  handle  with  the  electronic
key still inside the vehicle.
 Retrieve  the  electronic  key
from the vehicle and lock
the doors again.
Once
• The  electronic  key  could  not
be  detected  when  the  power
switch  was  pressed  after  the
doors were  unlocked with the
mechanical key. 
• The  electronic  key  could  not
be  detected  two  consecutive
times  when  the  power  switch
was pressed. 
 Touch the electronic key to
the  power  switch  while
depressing  the  brake
pedal.
Once
An  attempt  was  made  to  start
the  hybrid  system  with  the  shift
lever in a position other than P.
Shift  the  shift  lever  to  P
and  start  the  hybrid  sys-
tem.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Flashes) 
     
        
        Page 500 of 596
5008-2. Steps to take in an emergency
PRIUS c_U
Power was turned off due to the
automatic power off function.
Next  time  when  starting
the  hybrid  system,
increase  the  engine  speed
slightly  and  maintain  that
level  for  approximately  5
minutes  to  recharge  the
12-volt-battery.
Once
The  electronic  key  has  a  low
battery.
Replace  the  electronic  key
battery. ( P. 449)
Once
The  driver’s  door  was  opened
and  closed  with  the  power
switch  turned  off  and  then  the
power  switch  was  put  in
ACCESSORY mode twice with-
out  the  hybrid  system  being
started.
Press  the  power  switch
while depressing the brake
pedal.
During  a  hybrid  system  starting
procedure  in  the  event  that  the
electronic key was not function-
ing  properly  ( P.  517),  the
power  switch  was  touched  with
the electronic key. 
 Press  the  power  switch
within  10  seconds  of  the
buzzer sounding.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes) 
     
        
        Page 515 of 596

5158-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
One of the following may be the cause of the problem:
● Vehicles  with  a  smart  key  system:  The  electronic  key  may  not  be
functioning properly. ( P. 517)
● There may not be sufficient f uel in the vehicle’s tank.
Refuel the vehicle. ( P. 219)
● Vehicles  with  immobilizer  syste m:  There  may  be  a  malfunction  in
the immobilizer system. ( P.   8 6 )
● There may be a malfunction i n the steering lock system.
● Vehicles with  a smart key  system : The hybrid  system may be mal-
functioning due to an electrical  problem such as an open circui t or a
blown  fuse.  However,  depending  on  the  type  of  malfunction,  an
interim measure is available to  start the hybrid system. (P. 516)
One of the following may be  the cause of the problem:
● The 12-volt battery  may be discharged. ( P. 519)
● The 12-volt battery terminal conn ections may be loose or corroded.
(  P. 429)
If  the hybrid system will not start
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. 186, 190)
The  interior  lights  and  headlights  are  dim,  or  the  horn  does  no t
sound or sounds at a low volume. 
     
        
        Page 516 of 596

5168-2. Steps to take in an emergency
PRIUS c_U
One of the following may be the cause of the problem:
● The 12-volt battery  may be discharged. ( P. 519)
● One  or  both  of  the  12-volt  battery  terminals  may  be  disconnecte d.
(  P. 429)
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 procedure except in case of emergency.
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power swi tch for about 15 seconds.
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 (vehicles with a smart key system)
1
2
3
4 
     
        
        Page 517 of 596

5178-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
Use the mechanical key (P.   1 1 9 )
in  order  to  perform  the  following
operations (driver’s door only):
Unlocks the doors
Locks all the doors
Turning  the  key  rearward  unlocks
the  driver’s  door.  Turning  the  key
once  again  within  5  seconds
unlocks the other doors.
Ensure that the shift lever is in  P and depress the brake pedal.
Touch  the  Toyota  emblem  side
of  the  electronic  key  to  the
power switch.
When  the  electronic  key  is
detected, a buzzer sounds and the
power switch will turn to ON mode. 
When  the  smart  key  system  is
deactivated  in  customization  set-
ting,  the  power  switch  will  turn  to
ACCESSORY mode.
If  the electronic key does not operate prop-
erly (vehicles with a smar t key system)
If  communication  between  the  electronic  key  and  vehicle  is
interrupted  ( P.  141)  or  the  electronic  key  cannot  be  used
because the battery is depleted, the smart key system and wire-
less  remote  control  cannot  be  used.  In  such  cases,  the  doors
can  be  opened  and  the  hybrid  system  can  be  started  by  follow-
ing the procedure below.
Locking and unlocking the doors
1
2
Starting the hybrid system
1
2