
3746-3. Do-it-yourself maintenance
PRIUS +_OM_OM47D30E_(EE)
WARNING
The engine compartment contains many mechanisms and fluids that may 
move suddenly, become hot, or become el ectrically energized. To avoid death 
or serious injury, observe the following precautions. 
■ When working on the engine compartment 
● Make sure that the “POWER ON” on the multi-information display or the 
smart entry & start system indicator, 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 discom- 
fort, consult a doctor. 
■ When working near the electric cooling fans or radiator grille 
Be sure the power switch is off. 
With the power switch in ON mode, the electric cooling fans may automati-
cally start to run if the air conditioning is on and/or the coolant temperature
is high. ( P. 386) 
■ Safety glasses 
Wear safety glasses to prevent flying or falling material, fluid spray, etc. 
from getting in your eyes.
NOTICE
■ If you remove the air cleaner filter 
Driving with the air cleaner filter removed may cause excessive engine wear 
due to dirt in the air. 
■ If the brake fluid level is low or high 
It is normal for the brake fluid level to go down slightly as the brake pads 
wear or when the fluid level in the accumulator is high. 
If the reservoir needs frequent refilling,  it may indicate a serious problem. 

3796-3. Do-it-yourself maintenance
PRIUS +_OM_OM47D30E_(EE)
6
Maintenance and care
Engine compartment
■12-volt battery
P. 389
Engine coolant reservoir
(P. 385)
Engine oil level dipstick
(P. 381)
Engine oil filler cap
(P. 383)
Power control unit coolant 
reservoir  (P. 385)Fuse box  (P. 419)
Radiator (P. 386)
Condenser  (P. 386)
Electric cooling fans
Washer fluid tank  (P. 387)1
2
3
4
5
6
7
8
9 

3856-3. Do-it-yourself maintenance
PRIUS +_OM_OM47D30E_(EE)
6
Maintenance and care
The coolant level is satisfactory if it is between the full (“FULL” or “F”)
and low (“LOW” or “L”) lines on the reservoir when the hybrid system
is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to
the “FULL” line. (P. 518)
■
Power control unit coolant reservoir
Reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F”
line. (P. 518)
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with
long-life hybrid organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -35C [-31F])
For more details about coolant, contact any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.
■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 retailer or Toyota autho-
rized repairer, or any reliable repairer, test the cap and check for leaks in the
cooling system.
Coolant
1
2
3
1
2
3 

3866-3. Do-it-yourself maintenance
PRIUS +_OM_OM47D30E_(EE)
Check the radiator and condenser and clear away any foreign objects.  
If either of the above parts is extremely dirty or you are not sure of 
their condition, have your vehicle inspected by any authorized Toyota 
retailer or Toyota authorized repairer, or any reliable repairer.
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 straight 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. 
■ When the electric cooling fans are operating 
Do not touch the engine compartment. 
With the power switch in ON mode, the electric cooling fans may automati- 
cally start to run if the air conditioning is on and/or the coolant temperature
is high. Be sure the power switch is off when working near the electric cool- 
ing fans or radiator grille. 

5197-2. Steps to take in an emergency
PRIUS +_OM_OM47D30E_(EE)
7
When trouble arises
The coolant level is satisfactory if it is between the “FULL” and 
“LOW” lines on the reservoir. 
Reservoir 
“FULL” line 
“LOW” line 
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 fans operate and to check for 
coolant leaks from the radiator or hoses.
The fans operate when the air condi tioning system is turned on immedi- 
ately after a cold start. Confirm that the fans are operating by checking 
the fan sound and air flow. If it is difficult to check these, turn the air con-
ditioning system on and off repeatedly. (The fans may not operate in 
freezing temperatures.)
If the fans are not operating: 
Stop the hybrid system immediately and contact any authorized 
Toyota retailer or Toyota authorized repairer, or any reliable 
repairer. 
If the fans are operating: 
Have the vehicle inspected at the nearest any authorized Toyota 
retailer or Toyota authorized repairer, or any reliable repairer.
4
1
2
3
5
6
7 

5207-2. Steps to take in an emergency
PRIUS +_OM_OM47D30E_(EE) 
■If the hybrid system overheat warning light comes on or the 
warning message indicating overheat is shown on the multi- 
information display 
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 fans
If a large amount of coolant 
leaks, immediately contact 
any authorized Toyota retailer 
or Toyota authorized repairer,
or any reliable repairer.
The coolant level is satisfactory 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. 
If water was added in an emer- 
gency, have the vehicle 
inspected at any authorized
Toyota retailer or Toyota autho- 
rized repairer, or any reliable 
repairer as soon as possible.
1
2
3
1
2
4
1
2
3
5 

5217-2. Steps to take in an emergency
PRIUS +_OM_OM47D30E_(EE)
7
When trouble arises
After stopping the hybrid system and waiting for 5 minutes or 
more, start the hybrid system and check for the instrument clus- 
ter or multi-information display. 
If the hybrid system overheat warning light does not turn off or 
the message does not disappear:  
Stop the hybrid system and contact any authorized Toyota 
retailer or Toyota authorized repairer, or any reliable repairer. 
If the hybrid system overheat warning light does not come on or 
the message is not displayed:  
The hybrid system temperature has dropped and the vehicle may 
be driven normally.
However, if the warning light comes on again frequently or the message 
appears again frequently, contact any authorized Toyota retailer or 
Toyota authorized repairer, or any reliable repairer.
WARNING
■ When inspecting under the hood of your vehicle 
Observe the following precautions. 
Failure to do so may result in serious injury such as burns. 
● 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. 
● After the hybrid system has been turned off, check that the indicator on the 
power switch and the “READY” indicator are off.  
When the hybrid system is operating, the gasoline engine may automati- 
cally 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 fingers 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. 
High temperature steam or coolant could spray out.
6