Page 580 of 784
580
PRIUS PRIME_OM_OM47A88U_(U)
7-3. Do-it-yourself maintenance
Engine compartment
Engine coolant reservoir (→ P. 584)
Fuse boxes ( →P. 630)
Engine oil level dipstick (→ P. 581)
Engine oil filler cap ( →P. 582)
Brake fluid reservoir (→ P. 590) Washer fluid tank (
→P. 592)
12-volt battery ( →P. 587)
Power control unit coolant
reservoir ( →P. 584)
Radiator ( →P. 586)
Condenser ( →P. 586)
Electric cooling fans1
2
3
4
5
6
7
8
9
10
11
Page 584 of 784
584
PRIUS PRIME_OM_OM47A88U_(U)
7-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “FULL” and “LOW”
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. 700)
■
Power control unit 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. 700)
Coolant
1
2
3
1
2
3
Page 585 of 784

PRIUS PRIME_OM_OM47A88U_(U)
5857-3. Do-it-yourself maintenance
7
Maintenance and care
■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.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -31 °F [-35 °C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deion-
ized water. (Minimum temperature: -44 °F [-42 °C])
For more details about coolant, contact your Toyota dealer.
■ 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 your Toyota dealer test the cap and check for
leaks in the cooling system.
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.
Page 586 of 784
586
PRIUS PRIME_OM_OM47A88U_(U)
7-3. Do-it-yourself maintenance
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is ex tremely dirty or you are not sure of
their condition, have yo ur vehicle inspected by your Toyota dealer.
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, t he electric cooling fans may automati-
cally start to run if the air condition ing 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.
Page 652 of 784
652
PRIUS PRIME_OM_OM47A88U_(U)
8-2. Steps to take in an emergency
If you think something is wrong
●Fluid leaks under the vehicle
(Water dripping from the air co nditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High coolant temperature warning light flashes or comes on
● Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
● Engine missing, stumbling or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, spon gy feeling, pedal almost touches
the floor
If you notice any of the follow ing symptoms, your vehicle proba-
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 655 of 784

6558-2. Steps to take in an emergency
PRIUS PRIME_OM_OM47A88U_(U)
8
When trouble arises
Slip indicator lightIndicates a malfunction in:
• The VSC system;
• The TRAC system; or
• The hill-start assist control system
→ Have the vehicle inspected by your Toyota dealer
immediately.
The light will flash when the ABS, VSC or TRAC system is
operating.
High coolant temperat ure warning light
• When the light flashes:
Indicates that the engine coolant temperature is too high
The light changes from a flashing to a solid light when
the temperature further increases
→ Immediately stop the vehicle in a safe place. ( →P. 700)
• When the light comes on without flashing: Indicates a malfunction in the exhaust heat recirculator
system
→ Have the vehicle inspected by your Toyota dealer
immediately.
(Flashes)
(If equipped)
ICS OFF indicator
Indicates a malfunction in the Intelligent Clearance Sonar
function
→ Have the vehicle inspected by your Toyota dealer.
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will come on when the Intelligent Clearance Sonar function is turned off ( →P. 431)
• The light will come on when the Intelligent Clearance Sonar function is operating ( →P. 435)
• The light will flash when the system cannot be temporar- ily used ( →P. 439)
Open door warning light (warning buzzer)*3
Indicates that a door is not fully closed
→ Check that all the doors are closed.
Low fuel level warning light
Indicates that remaining fuel is approximately 1.7 gal.
(6.4 L, 1.4 Imp.gal.) or less
→ Refuel the vehicle.
Warning lightWarning light/Details/Actions
Page 700 of 784
700
PRIUS PRIME_OM_OM47A88U_(U)
8-2. Steps to take in an emergency
If your vehicle overheats
■If the high 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 radiator core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light ( →P. 655) comes on
or flashes, or a loss of hybrid system power is experienced. (For
example, the vehicle s peed does not increase.)
● “Hybrid System Overhe ated” is shown on the multi-information
display.
● Steam comes out from under the hood.
Correction procedures
1
2
3
1
2
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7018-2. Steps to take in an emergency
PRIUS PRIME_OM_OM47A88U_(U)
8
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 th e radiator or hoses.
The fans operate when the temperature setting is adjusted to “LO” and
“A/C” switch (
*1 • *2) is turned on immediately 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 “A/C” switch
(
*1 • *2) on and off repeatedly. (The fans may not
operate in freezing temperatures.)
*1: Vehicles with 7-inch display
*2: Vehicles with 11.6-inch display
If the fans are not operating:
Stop the hybrid system immediately and contact your Toyota
dealer.
If the fans are operating:
Have the vehicle in spected at the nearest Toyota dealer.
4
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2
3
5
6
7