Page 321 of 492

3217-3. Do-it-yourself maintenance
7
Maintenance and care
YARIS_HV_EE_OM52F30E
WARNING
The engine compartment contains many mechanisms and fluids that may
move suddenly, become hot, or become electrically energized. To avoid death
or serious injury, observe the following precautions.
■ When working on the engine compartment
● Make sure that the power switch is in the “LOCK” position (vehicles with-
out a smart entry & start system) or the power switch off (vehicles with a
smart entry & start system) and the “READY” indicator are both off.
● Keep hands, clothing and tools away from the moving fan.
● Be careful not to touch the engine, power control unit, radiator, exhaust
manifold, etc. right after driving as they may be hot. Oil and other fluids
may also be hot.
● Do not leave anything that may burn easily, such as paper and rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes
are flammable.
● Take care because brake fluid can harm your hands or eyes and damage
painted surfaces. If fluid gets on your hands or in your eyes, flush the
affected area with clean water immediately.
If you still experience discomfort, consult a doctor.
■ When working near the electric cooling fan or radiator grille
XVehicles without a smart entry & start system
Be sure the power switch is in the “LOCK” position.
With the power switch in the “ON” position, the electric cooling fan may
automatically start to run if the air conditioning is on and/or the coolant tem-
perature is high. ( →P. 332)
XVehicles with a smart entry & start system
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fan may automati-
cally start to run if the air conditioning is on and/or the coolant temperature
is high. ( →P. 332)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
Page 327 of 492
3277-3. Do-it-yourself maintenance
7
Maintenance and care
YARIS_HV_EE_OM52F30E
Engine compar tment
Fuse boxes (→P. 365)
Engine oil filler cap
( →P. 329)
Engine coolant radiator cap
Power control unit coolant res-
ervoir ( →P. 331)
Engine coolant reservoir
( →P. 331)
Engine/power control unit
coolant radiator ( →P. 332)
Electric cooling fan
Condenser ( →P. 332)
Engine oil level dipstick
( →P. 328)
Washer fluid tank ( →P. 333)
1
2
3
4
5
6
7
8
9
10
Page 332 of 492

3327-3. Do-it-yourself maintenance
YARIS_HV_EE_OM52F30E
■ 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 401 of 492

4018-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_EE_OM52F30E
*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 447 of 492

4478-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_EE_OM52F30E
WARNING
■ When replacing the 12-volt battery
→ P. 339
■ 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 448 of 492

4488-2. Steps to take in an emergency
YARIS_HV_EE_OM52F30E
If your vehicle overheats
●The high engine coolant temperature warning light (→P. 396)
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. 400) 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 449 of 492

4498-2. Steps to take in an emergency
8
When trouble arises
YARIS_HV_EE_OM52F30E
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 450 of 492
4508-2. Steps to take in an emergency
YARIS_HV_EE_OM52F30E
■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