2012 TOYOTA PRIUS C 12-volt battery

378 4-3. Do-it-yourself maintenance
CAUTION
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may
produce hydrogen gas which is flammable and explosive. To reduce the risk
of death or serious injury, take the following precautions while working on or
near the 12-volt battery:
●Do not cause sparks by touching the 12-volt battery terminals with tools.
● Do not smoke or light a match near the 12-volt battery.
● Avoid contact with eyes, skin and clothes.
● Never inhale or swallow electrolyte.
● Wear protective safety glasses when working near the 12-volt battery.
● Keep children away from the 12-volt battery.
■ Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt
battery in a garage or closed room where there is insufficient ventilation.
■ When disconnecting the 12- volt battery terminals
Always disconnect the negative (-) terminal first. If the positive (+) terminal is
disconnected first and touches a surrounding metal surface it may cause
sparks resulting in a fire or it may result in an electric shock, death or serious
injury.
■ How to recharge the 12-volt battery
Only perform a slow charge (3.5 A or less). The 12-volt battery may explode
if charged at a quicker rate.

379
4-3. Do-it-yourself maintenance
4
Maintenance and care
CAUTION
■
Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immedi-
ate medical attention. If possible, continue to apply water with a sponge or
cloth while traveling to the nearest medical facility.
● If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical
attention immediately.
● If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the cloth-
ing and follow the procedure above if necessary.
● If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention
immediately.
■ When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may ca\
use
gas (hydrogen) to enter the passenger co mpartment, causing a fire or explo-
sion.
For replacement of the 12-volt battery, contact your Toyota dealer.
NOTICE
■ When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating.
Also, be sure all accessories are turned off.

When trouble arises5
423
5-1. Essential informationEmergency flashers ......... 424
If your vehicle needs to be towed ............................. 425
If you think something is wrong ......................... 430 5-2. Steps to take in an
emergency
If a warning light turns on or a warning buzzer
sounds ........................... 431
If a warning message is displayed .................... 441
If you have a flat tire......... 457
If the hybrid system will not start .......................... 469
If the shift lever cannot be shifted from P............ 471
If you lose your keys ........ 472
If the electronic key does not operate properly....... 473
If the vehicle 12-volt battery is discharged ...... 475
If your vehicle overheats ....................... 480
If the vehicle becomes stuck .............................. 485
If your vehicle has to be stopped in an
emergency ..................... 486

424
5-1. Essential information
Emergency flashers
■Emergency flashers
If the emergency flashers are used for a long time while the hybrid system is
not operating (while the “READY” indicator is not illuminated), the 12-volt
battery may discharge.
The emergency flashers are used to warn other drivers when the
vehicle has to be stopped in the road due to a breakdown, etc.
Press the switch.
All the turn signal lights will
flash. To turn them off, press
the switch once again.

5
When trouble arises
435
5-2. Steps to take in an emergency
*: Driver's and front passen
ger's seat belt buzzer:
The driver's and front passenger's seat belt buzzer sounds to alert the driver
and front passenger that his or her seat belt is not fastened. Once the engine
switch is turned to the “ON” or “START” position (vehicles without a smart
key system) or the “POWER” switch is turned to ON mode (vehicles with a
smart key system), the buzzer sounds for 6 seconds. If the vehicle reaches a
speed of 12 mph (20 km/h), the buzzer sounds once. If the seat belt is still
unfastened after 30 seconds, the buzzer will sound intermittently for 10 sec-
onds. Then, if the seat belt is still unfastened, the buzzer will sound in a dif-
ferent tone for 20 more seconds.
■ SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors, driver's seat belt buckle switch, front passen-
ger occupant classification system (ECU and sensors), “AIR BAG ON” indi-
cator light, “AIR BAG OFF” indicator light, front passenger's seat belt buckle
switch, seat belt pretensioner assemblies, airbags, interconnecting wiring
and power sources. ( P. 432)
■ Front passenger detection sensor, passenger seat belt reminder and
warning buzzer
● If luggage is placed on the front passenger seat, the front passenger
detection sensor may cause the warning light to flash and the warning
buzzer to sound even if a passenger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passen-
ger, and the warning light may not operate properly.
■ Electric power steering system wa rning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power st eering system warning light may come on
and the warning buzzer may sound.

5
When trouble arises
469
5-2. Steps to take in an emergency
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the
situation. Check the following and perform the appropriate proce-
dure:
■ The hybrid system will not start even though the correct
starting procedure is being followed. ( P. 158, 162)
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. 474)
● There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ( P. 105)
● Vehicles with immobilizer sy stem: There may be a malfunc-
tion in the immobilizer system. ( P. 1 1 0 )
● There may be a malfunction in the steering lock system.
● Vehicles with a smart key syst em: The hybrid system may be
malfunctioning due to an electrical problem such as an open
circuit or a blown fuse. However, depending on the type of
malfunction, an interim measure is available to start the hybrid
system. ( P. 470)
■ The interior lights and headlights are dim, or the horn does
not sound or sounds at a low volume.
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 475)
● The 12-volt battery terminal c onnections may be loose or cor-
roded.

470 5-2. Steps to take in an emergency
Emergency start function (vehicles with a smart key system)When the hybrid system does not start, the following steps can be
used as an interim measure to start the hybrid system if the
“POWER” switch is functioning normally: Shift the shift lever to P.
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. Have the vehicle inspected by your
Toyota dealer.
■ The interior lights and headlights do not turn on, or the horn
does not sound.
One of the following may be the cause of the problem:
●One or both of the 12-volt ba ttery terminals may be discon-
nected.
● The 12-volt battery may be discharged. ( P. 475)
Contact your Toyota dealer if the problem cannot be repaired, or if
repair procedures are unknown.
STEP1
STEP2
STEP3
STEP4

5
When trouble arises
475
5-2. Steps to take in an emergency
If the vehicle 12-volt batter y is discharged
The following procedures may be used to start the hybrid system if
the vehicle’s 12-volt battery is discharged.
You can also call your Toyota deal er or a qualified repair shop.
If you have a set of jumper (or booster) cables and a second vehi-
cle with a 12-volt battery, you can jump start your vehicle by follow-
ing the steps below.
Remove the 12-volt battery
cover under the rear right
seat. (P. 375)
Connect the jumper cables accord ing to the following procedure:
Connect a positive jumper cable clamp to the positive (+) battery
terminal on your vehicle.
Connect the clamp on the other e nd of the positive cable to the
positive (+) battery termin al on the second vehicle.
Connect a negative cable clamp to the negative (-) battery termi-
nal on the second vehicle.
Connect the clamp at the other en d of the negative cable to the
negative (-) battery terminal on your vehicle as shown in the
illustration.
STEP1
STEP2