coolant TOYOTA PRIUS PRIME 2021 Owners Manual (in English)

PRIUS PRIME_OM_OM47D71U_(U)
2033. Instrument cluster
3
Instrument cluster
*1: These lights turn on when the power switch is turned to ON mode to indi-
cate that a system check is being performed. They will turn off after the
hybrid system is on, or after a few seconds. There may be a malfunction in
a system if a light does not come on, or turn off. Have the vehicle
inspected by your Toyota dealer.
*2: The light flashes or illuminates to indicate a malfunction.
*3: The light flashes to indicate a malfunction.
*1High coolant temperature warning light P. 676
*1, 3PKSB OFF indicator (if equipped) P. 676
Open door warning light P. 676
Low fuel level warning light P. 676
Driver’s and front passenger’s seat belt
reminder lightP. 677
Rear passengers’ seat belt reminder light
(U.S.A.)P. 677
Rear passengers’ seat belt reminder light
(Canada)P. 677
*1Master warning light P. 677
*1Tire pressure warning lightP. 677
Warning lightsPages

208
PRIUS PRIME_OM_OM47D71U_(U)
3. Instrument cluster
■BSM (Blind Spot Monitor) outside rear view mirror indicators
(if equipped) (P. 432)
• When the BSM function is enabled on the screen of the multi-infor-
mation display, the power switch is turned to ON mode.
If the system is functioning correctly, the BSM outside rear view mirror indi-
cators will turn off after a few seconds.
If the BSM outside rear view mirror indicators do not illuminate or do not
turn off, there may be a malfunction in the system.
If this occurs, have the vehicle inspected by your Toyota dealer. ●Indicators are also displayed on the out-
side rear view mirrors.
●In order to confirm operation, the BSM
outside rear view mirror indicators illumi-
nate in the following situations:
• When the power switch is in ON
mode, the BSM function is enabled
on the screen of the multi-infor-
mation display.
WARNING
■If a safety system warning light does not come on
Should a safety system light such as the ABS and SRS warning light not
come on when you start the hybrid system, this could mean that these sys-
tems are not available to help protect you in an accident, which could result
in death or serious injury. Have the vehicle inspected by your Toyota dealer
immediately if this occurs.
NOTICE
■To prevent damage to the engine and its components
The engine may be overheating if the high coolant temperature warning
light comes on or flashes. In this case, immediately stop the vehicle in a
safe place, and check the engine after it has cooled completely. (P. 721)

507
PRIUS PRIME_OM_OM47D71U_(U)
5-6. Driving tips
5
Driving
Winter driving tips
●Use fluids that are appropriate to the prevailing outside tempera-
tures.
• Engine oil
• Engine/power control unit coolant
• Washer fluid
●Have a service technician inspect the condition of the 12-volt bat-
tery.
●Have the vehicle fitted with four snow tires or purchase a set of tire
chains for the front tires.
Ensure that all tires are the same size and brand, and that chains match
the size of the tires.
Perform the following according to the driving conditions:
●Do not try to forcibly open a window or move a wiper that is frozen.
Pour warm water over the frozen area to melt the ice. Wipe away
the water immediately to prevent it from freezing.
●To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
●Check for and remove any excess ice or snow that may have accu-
mulated on the exterior lights, vehicle’s roof, chassis, around the
tires or on the brakes.
●Remove any snow or mud from the bottom of your shoes before
getting in the vehicle.
Carry out the necessary preparations and inspections before
driving the vehicle in winter. Always drive the vehicle in a man-
ner appropriate to the prevailing weather conditions.
Preparation for winter
Before driving the vehicle

5186-1. Using the air conditioning system and defogger
PRIUS PRIME_OM_OM47D71U_(U)
■Heating
●In HV mode, the gasoline engine may operate in order to extract heat from
the engine coolant via the heater.
●In EV mode, heating is done by a heat pump system.
• When the outside temperature is low or it is snowing, compared to con-
ventional vehicles, heating may be less effective and warm air may not
come out.
• If frost has formed on the outside heat exchanger, the heating perfor-
mance will decline. The frost can be removed from the outside heat
exchanger by operating the Remote Air Conditioning System before driv-
ing (P. 535). When frosted over, the heating operation of the Remote
Air Conditioning System starts after defrosting.
• When is turned on, the heating is controlled optimally. Therefore,
the set heating performance may not be achieved even if the fan speed
setting is increased.
●In the following situations the gasoline engine may operate in order to
extract heat from the engine coolant via the heater even in EV mode.
• The outside temperature is approximately 14°F (-10°C) or low
• is operating
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and
the ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow
immediately after is pressed.
■Water droplets during air conditioning operation• When the outside heat exchanger is
frosted over, fan speed declines and it
may become harder to heat the inte-
rior. However, it is not a malfunction.
In this situation, the air temperature
from the outlets may not change even
though the set temperature is raised.
The outside heat exchanger, accumulator
and air conditioning piping may incur con-
densation or frost may form. During or
after the air conditioning operation, water
droplets may fall from the vehicle. How-
ever, it is not a malfunction.
Outside heat exchanger
Outside heat exchanger
Accumulator

PRIUS PRIME_OM_OM47D71U_(U)
5296-1. Using the air conditioning system and defogger
6
Interior features
■Heating
●In HV mode, the gasoline engine may operate in order to extract heat from
the engine coolant via the heater.
●In EV mode, heating is done by a heat pump system.
• When the outside temperature is low or it is snowing, compared to con-
ventional vehicles, heating may be less effective and warm air may not
come out.
• If frost has formed of the outside heat exchanger, the heating perfor-
mance will decline. The frost can be removed from the outside heat
exchanger by operating the Remote Air Conditioning System before driv-
ing (P. 535). When frosted over, the heating operation of the Remote
Air Conditioning System starts after defrosting.
• When is turned on, the heating is controlled optimally. There-
fore, the set heating performance may not be achieved even if the fan
speed setting is increased.
●In the following situations the gasoline engine may operate in order to
extract heat from the engine coolant via the heater even in EV mode.
• The outside temperature is approximately 14°F (-10°C) or low
• is operating
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and
the ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow
immediately after is pressed.
■Water droplets during air conditioning operation• When the outside heat exchanger is
frosted over, fan speed declines and it
may become harder to heat the inte-
rior. However, it is not a malfunction.
In this situation, the air temperature
from the outlets may not change even
though the set temperature is raised.
The outside heat exchanger, accumulator
and air conditioning piping may incur con-
densation or frost may form. During or
after the air conditioning operation, water
droplets may fall from the vehicle. How-
ever, it is not a malfunction.
Outside heat exchanger
Outside heat exchanger
Accumulator

590
PRIUS PRIME_OM_OM47D71U_(U)
7-2. Maintenance
General maintenance
Listed below are the general maintenance items that should be
performed at the intervals specified in the “Owner’s Warranty
Information Booklet” or “Owner’s Manual Supplement/Sched-
uled Maintenance Guide”. It is recommended that any problem
you notice should be brought to the attention of your Toyota
dealer or qualified service shop for advice.
Engine compartment
ItemsCheck points
12-volt batteryCheck the connections. (P. 607)
Brake fluidIs the brake fluid at the correct level? (P. 610)
Engine/power control
unit coolantIs the engine/power control unit coolant at the
correct level? (P. 604)
Engine oilIs the engine oil at the correct level? (P. 601)
Exhaust systemThere should not be any fumes or strange
sounds.
Radiator/condenserThe radiator and condenser should be free from
foreign objects. (P. 606)
Washer fluidIs there sufficient washer fluid? (P. 612)

594
PRIUS PRIME_OM_OM47D71U_(U)
7-3. Do-it-yourself maintenance
Do-it-yourself ser vice precautions
If you perform maintenance by yourself, be sure to follow the
correct procedure as given in these sections.
ItemsParts and tools
12-volt battery
condition
(P. 6 0 7 )•Grease
• Conventional wrench (for terminal clamp bolts)
Brake fluid level
(P. 6 1 0 )
• SAE J1703 or FMVSS No.116 DOT 3 or SAE J1704
or FMVSS No.116 DOT 4 brake fluid
• Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power
control unit cool-
ant level
(P. 6 0 4 )
• “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
For the U.S.A.:
“Toyota Super Long Life Coolant” is pre-mixed with
50% coolant and 50% deionized water.
For Canada:
“Toyota Super Long Life Coolant” is pre-mixed with
55% coolant and 45% deionized water.
• Funnel (used only for adding coolant)
Engine oil level
(P. 6 0 1 )• “Toyota Genuine Motor Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses (P. 650)• Fuse with same amperage rating as original
Hybrid battery
(traction battery)
air intake vent
(P. 5 8 2 )
• Vacuum cleaner, etc.
• Flathead screwdriver
Headlight aim
(P. 6 5 3 )• Phillips-head screwdriver
Light bulbs
(P. 6 5 5 )
• Bulb with same number and wattage rating as origi-
nal
• Flathead screwdriver
• Wrench
Radiator and con-
denser (P. 606)

PRIUS PRIME_OM_OM47D71U_(U)
5957-3. Do-it-yourself maintenance
7
Maintenance and care
Tire inflation
pressure
(P. 623)• Tire pressure gauge
• Compressed air source
Washer fluid
(P. 6 1 2 )• Water or washer fluid containing antifreeze (for win-
ter use)
• Funnel (used only for adding water or washer fluid)
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 “Accessory”, “Ignition ON” or mileage display
(P. 210) on the main display 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.
●Be extremely cautious when working on the 12-volt battery. It contains poi-
sonous and corrosive sulfuric acid.
■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. 606)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
ItemsParts and tools

600
PRIUS PRIME_OM_OM47D71U_(U)
7-3. Do-it-yourself maintenance
Engine compartment
IO73PH112
Engine coolant reservoir
(P. 604)
Fuse boxes (P. 650)
Engine oil level dipstick
(P. 601)
Engine oil filler cap (P. 602)
Brake fluid reservoir
(P. 610)Washer fluid tank (P. 612)
12-volt battery (P. 607)
Power control unit coolant
reservoir (P. 604)
Radiator (P. 606)
Condenser (P. 606)
Electric cooling fans1
2
3
4
5
6
7
8
9
10
11

604
PRIUS PRIME_OM_OM47D71U_(U)
7-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “MAX” and “MIN”
lines on the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“MAX” line
“MIN” line
If the level is on or below the
“MIN” line, add coolant up to the
“MAX” line. (P. 721)
■
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. 721)
Coolant
1
2
3
1
2
3