2019 TOYOTA PRIUS PRIME coolant temperature

PRIUS PRIME_OM_OM47D13U_(U)
1973. Instrument cluster
3
Instrument cluster
Warning lights inform the driver of malfunctions in any of the vehicle’s
systems.
Warning lights
Warning lightsPages
*1Brake system warning light (U.S.A.) P. 660
*1Brake system warning light (Canada)
(Red)P. 660
*1Brake system warning light
(Yellow)P. 660
*1Charging system warning light
P. 660
*1Low engine oil pressure warning lightP. 660
*1Malfunction indicator lamp (U.S.A.) P. 660
*1Malfunction indicator lamp (Canada)P. 660
*1SRS warning light P. 661
*1ABS warning light (U.S.A.) P. 661
*1ABS warning light (Canada)P. 661
*1Electric power steering system warning light
(Red/yellow)P. 661
*1, 2PCS warning light
P. 661
*1Slip indicator lightP. 661
*1High coolant temperature warning lightP. 662

PRIUS PRIME_OM_OM47D13U_(U)
2033. Instrument cluster
3
Instrument cluster
■BSM (Blind Spot Monitor) outsid e rear view mirror indicators
(if equipped) ( P. 417)
• When the BSM function is enabled on the screen of the multi-i nfor-
mation display, the power switch is turned to ON mode.
If the system is functioning correctly, the BSM outside rear vi ew mirror indi-
cators will turn off after a few seconds.
If the BSM outside rear view mirror indicators do not illuminat e or do not
turn off, there may be a malfunction in the system.
If this occurs, have the vehicle inspected by your Toyota deale r.
●
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 li ght 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, whic h 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. 707)

5026-1. Using the air conditioning system and defogger
PRIUS PRIME_OM_OM47D13U_(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 befor e driv-
ing ( P. 518). 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 temperatur e 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_OM47D13U_(U)
5136-1. 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 befor e driv-
ing ( P. 518). 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 temperatur e 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_OM47D13U_(U)
5817-3. Do-it-yourself maintenance
7
Maintenance and care
Tire inflation
pressure
( P. 609)• Tire pressure gauge
• Compressed air source
Washer fluid
( P. 5 9 8 )• 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 displa y
( P. 205) 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 r ags, 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
poisonous 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. 592)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
ItemsParts and tools

PRIUS PRIME_OM_OM47D13U_(U)
5917-3. 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-bora te 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 c oolant 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 c aps.
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 cor rect 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 p arts or paint.

592
PRIUS PRIME_OM_OM47D13U_(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 extremely dirty or you are not sure of
their condition, have your vehic le inspected by your Toyota dea ler.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and c ause 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.

659
PRIUS PRIME_OM_OM47D13U_(U)
8
When trouble arises
8-2. Steps to take in an emergency
If you think something is wrong
●Fluid leaks un der the vehicle
(Water dripping from the air conditioning a fter use is normal.)
● Flat-looking tires or uneven tire wear
● High coolant temperature warni ng 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, stumb ling or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one s ide when driving on a level road
● Loss of brake effectiveness, spongy feeling, pedal almost touch es
the floor
If you notice any of the followi ng symptoms, your vehicle proba -
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms