2020 TOYOTA PRIUS PLUG-IN HYBRID engine coolant

2153. Instrument cluster
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Instrument cluster
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
Warning lights inform the driver of malfunctions in any of the vehicle’s
systems.
Warning lights
Warning lightsPages
*1Brake system warning light (Red) P. 714
*1Brake system warning light (Yellow) P. 714
*1Charging system warning light P. 714
*1Low engine oil pressure warning light P. 715
*1Malfunction indicator lamp P. 715
*1SRS warning light P. 715
*1ABS warning light P. 715
*1Electric power steering system warning light
(Red/yellow) P. 715
*1, 2PCS warning light P. 716
LTA indicator (Orange) P. 716
*1Slip indicator light P. 716
*1High coolant temperature warning light P. 716
*1, 3PKSB OFF indicator (if equipped) P. 717
Open door warning light P. 717

2213. Instrument cluster
3
Instrument cluster
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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 any authorized
Toyota retailer or Toyota authorized repairer, or any reliable repairer imme-
diately 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. 761)

5665-6. Driving tips
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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

5796-1. Using the air conditioning system and defogger
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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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 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 Ai r Conditioning System before driv-
ing ( P. 585). 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 approx imately -10°C (14°F) 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.
• 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.Outside heat exchanger

6297-2. Maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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Maintenance and care
■Where to go for maintenance service?
In order to maintain your vehicle in the best possible condition, Toyota recom-
mends that maintenance service operations as well as other inspections and
repairs be carried out by authorized Toyota retailers or Toyota authorized
repairers, or any reliable repairers. For repairs and services covered by your
warranty, please visit an authorized Toyota retailer or repairer, who will use
genuine Toyota parts in repairing any difficulties you may encounter. There
can also be advantages in utilizing authorized Toyota retailers or repairers for
non-warranty repairs and services, as members of the Toyota network will be
able to expertly assist you with any difficulties you may encounter.
Your Toyota retailer or Toyota authorized repairer, or any reliable repairer will
perform all of the scheduled maintenance on your vehicle reliably and eco-
nomically due to their experience with Toyota vehicles.
■Does your vehicle need repairs?
Be on the alert for changes in performance and sounds, and visual tip-offs
that indicate service is needed. Some important clues are:
●Engine missing, stumbling or pinging
●Appreciable loss of power
●Strange engine noises
●A fluid leak under the vehicle (However, water dripping from the air condi-
tioning system after use is normal.)
●Change in exhaust sound (This may indicate a dangerous carbon monoxide
leak. Drive with the windows open and have the exhaust system checked
immediately.)
●Flat-looking tires, excessive tire squeal when cornering, uneven tire wear
●Vehicle pulls to one side when driven straight on a level road
●Strange noises related to suspension movement
●Loss of brake effectiveness, spongy feeling brake pedal, pedal almost
touches the floor, vehicle pulls to one side when braking
●Engine coolant temperature continually higher than normal (P. 716, 761)
If you notice any of these clues, take your vehicle to any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repairer as soon as pos-
sible. Your vehicle may need adjustment or repair.

6317-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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Maintenance and care
Do-it-yourself service 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. 644)• Warm water • Baking soda • Grease
• Conventional wrench (for terminal clamp bolts)
• Distilled water
Engine/power
control unit
coolant level
(P. 641)• “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 pre-mixed with
50% coolant and 50% deionized water.
• Funnel (used only for adding coolant)
Engine oil level
(P. 638)• “Toyota Genuine Motor Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses (P. 6 9 1 )• Fuse with same amperage rating as original
Hybrid battery
(traction battery)
air intake vent
(P. 623)
• Vacuum cleaner, etc.
• Flathead screwdriver
Light bulbs
(P. 695)
• Bulb with same number and wattage rating as origi-
nal
• Flathead screwdriver
• Wrench
Radiator and
condenser
(P. 643)

Tire inflation
pressure
(P. 665)• Tire pressure gauge
• Compressed air source
Washer fluid
(P. 648)• Water or washer fluid containing antifreeze (for win-
ter use)
• Funnel (used only for adding water or washer fluid)

6327-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(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 “Accessory”, “Ignition ON” or mileage display (P. 223)
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.
● 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. 643)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.

6377-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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Maintenance and care
Engine compartment
IO73PH114
Engine coolant reservoir
( P. 641)
Fuse boxes ( P. 691)
Engine oil level dipstick
( P. 638)
Engine oil filler cap ( P. 639)
Washer fluid tank ( P. 648)
12-volt battery ( P. 644)
Power control unit coolant
reservoir ( P. 641)
Radiator ( P. 643)
Condenser ( P. 643)
Electric cooling fans
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