Page 335 of 504
3357-3. Do-it-yourself maintenance
7
Maintenance and care
YARIS_HV_OM_Europe_OM52G76E
Engine compar tment
Fuse boxes (P. 373)
Engine oil filler cap
( P. 337)
Engine coolant radiator cap
Power control unit coolant res-
ervoir ( P. 339)
Engine coolant reservoir
( P. 339)
Engine/power control unit
coolant radiator ( P. 340)
Electric cooling fan
Condenser ( P. 340)
Engine oil level dipstick
( P. 336)
Washer fluid tank ( P. 341)
1
2
3
4
5
6
7
8
9
10
Page 340 of 504

3407-3. Do-it-yourself maintenance
YARIS_HV_OM_Europe_OM52G76E
■ If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have any authorized Toyota dealer or repairer, or
another duly qualified and equipped professional, test the cap and check for
leaks in the cooling system.
Check the radiator and condenser and clear away any foreign objects.
If any of the above parts is extremely dirty or you are not sure of their
condition, have your vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and equipped profes-
sional.
WARNING
■ When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps.
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
■ When adding coolant
Coolant is neither plain water nor stra ight antifreeze. The correct mixture of
water and antifreeze must be used to provide proper lubrication, corrosion
protection and cooling. Be sure to read the antifreeze or coolant label.
■ If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Radiator and condenser
WARNING
■ When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause seri-
ous injuries, such as burns.
Page 409 of 504

4098-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_OM_Europe_OM52G76E
*3: Open door warning buzzer:
A buzzer will sound if the vehicle reaches a speed of 5 km/h (3 mph) or
more with any door open.
*4: Driver’s and passenger’s seat belt buzzer:
The driver’s and passenger’s seat belt buzzer sounds to alert the driver
and passenger that his or her seat belt is not fastened. The buzzer sounds
for 30 seconds after the vehicle reaches a speed of at least 20 km/h
(12 mph). Then, if the seat belt is still unfastened, the buzzer will sound in
a different tone for 90 more seconds.
Carrying out the corresponding action turns the warning light off.
■ Passenger detection sensor and passenger seat belt reminder
● If luggage is placed on a passenger seat, the passenger detection sensor
may cause the warning light to flash even if a passenger is not sitting in the
seat.
● If a cushion is placed on the seat, the sensor may not detect a passenger,
and the warning light may not operate properly.
■ If the malfunction indicator lamp comes on while driving
For some models, the malfunction indicator lamp will come on if the fuel tank
becomes completely empty. If the fuel tank is empty, refuel the vehicle imme-
diately. The malfunction indicator lamp will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Toy-
ota dealer or repairer, or another duly qualified and equipped professional as
soon as possible.
Other warning light
Warning lightWarning light/Details/Actions
(If equipped)
Go to service warning light
Indicates that 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 battery) cooling component at any autho-
rized Toyota dealer or repairer, or another duly quali-
fied and equipped professional.
Page 454 of 504

4548-2. Steps to take in an emergency
YARIS_HV_OM_Europe_OM52G76E
WARNING
■When replacing the 12-volt battery
P. 347
■ 12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte,
while related parts contain lead and lead compounds. Observe the following
precautions when handling the 12-volt battery:
● When working with the 12-volt battery, always wear safety glasses and
take care not to allow any battery fluids (acid) to come into contact with
skin, clothing or the vehicle body.
● Do not lean over the 12-volt battery.
● In the event that battery fluid comes into contact with the skin or eyes,
immediately wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention
can be received.
● Always wash your hands after handling the battery support, terminals, and
other battery-related parts.
● Do not allow children near the 12-volt battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fan.
■ Exclusive jump starting terminal
The exclusive jump starting terminal is to be used when charging the 12-volt
battery from another vehicle in an emergency. It cannot be used to jump
start another vehicle.
Page 455 of 504

4558-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_OM_Europe_OM52G76E
If your vehicle overheats
●The high engine coolant temperature warning light (P. 404)
comes on or flashes, or a loss of hybrid system power is experi-
enced. (For example, the vehicle speed does not increase.)
● If the hybrid system overheat warning light (P. 408) comes on.
● Steam comes out from under the hood.
■If the high engine coolant temperature warning light comes on
or flashes
Stop the vehicle in a safe place and turn off the air conditioning
system, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently,
inspect the hoses and radia-
tor core (radiator) for any
leaks.
Radiator
Cooling fan
If a large amount of coolant
leaks, immediately contact any
authorized Toyota dealer or
repairer, or another duly quali-
fied and equipped professional.
The following may indicate that your vehicle is overheating:
Correction procedures
1
2
3
1
2
Page 456 of 504

4568-2. Steps to take in an emergency
YARIS_HV_OM_Europe_OM52G76E
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for
coolant leaks from the radiator or hoses.
The fan operates when the air condi tioning system is turned on immedi-
ately after a cold start. Confirm that the fan is operating by checking the
fan sound and air flow. If it is difficult to check these, turn the air condi-
tioning system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the hybrid system immediately and contact any authorized
Toyota dealer or repairer, or another duly qualified and equipped
professional.
If the fan is operating:
Have the vehicle inspected at the nearest authorized Toyota
dealer or repairer, or another duly qualified and equipped profes-
sional.
4
1
2
3
5
6
7
Page 457 of 504
4578-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_OM_Europe_OM52G76E
■If the hybrid system overheat warning light comes on
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has
cooled down, inspect the
hoses and radiator core
(radiator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant
leaks, immediately contact any
authorized Toyota dealer or
repairer, or another duly quali-
fied and equipped professional.
The coolant level is satisfac-
tory if it is between the “F”
and “L” lines on the reservoir.
Reservoir
“F” line
“L” line
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
1
2
3
1
2
4
1
2
3
5
Page 458 of 504

4588-2. Steps to take in an emergency
YARIS_HV_OM_Europe_OM52G76E
Start the hybrid system and check for the hybrid system overheat
warning light.
If the warning light does not go off:
Stop the hybrid system and contact any authorized Toyota dealer or
repairer, or another duly qualified and equipped professional.
If the warning light goes off:
Have the vehicle inspected at the nearest authorized Toyota dealer
or repairer, or another duly qualified and equipped professional.
WARNING
■ To prevent an accident or injury when inspecting under the hood of
your vehicle
● If steam is seen coming from under the hood, do not open the hood until
the steam has subsided. The engine compartment may be very hot, caus-
ing serious injuries such as burns.
● Check that the “READY” indicator is off.
● On hybrid vehicles, the gasoline engine may automatically start, or the
cooling fan may suddenly operate even if the gasoline engine stops. Do
not touch or approach rotating parts such as the fan, which may lead to fin-
gers or clothing (especially a tie, a scarf or a muffler) getting caught,
resulting in serious injury.
● Do not loosen the coolant reservoir cap while the hybrid system and radia-
tor are hot.
Serious injuries, such as burns, may result from hot coolant and steam
released under pressure.
6