coolant temperature TOYOTA PRIUS PLUG-IN HYBRID 2022 Owners Manual

2053. Instrument cluster
3
Instrument cluster
Prius Plug-in Hybrid_OM_OM47E75E_(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. 657
*1Brake system warning light (Yellow) P. 657
*1Charging system warning light P. 657
*1Low engine oil pressure warning light P. 658
*1Malfunction indicator lamp P. 658
*1SRS warning light P. 658
*1ABS warning light P. 658
*1Electric power steering system warning light
(Red/yellow) P. 658
*1, 2PCS warning light P. 659
LTA indicator (Orange) P. 659
*1Slip indicator light P. 659
*1High coolant temperature warning light P. 659
*1, 3PKSB OFF indicator (if equipped) P. 660
Open door warning light P. 660

2113. Instrument cluster
3
Instrument cluster
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
WARNING
QIf 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 any a uthorized
Toyota retailer or Toyota authorized repairer, or any reliable repairer imme-
diately if this occurs.
NOTICE
Q To prevent damage to the engine and its components
The engine may be overheating if the high coolant temperature w arning
light comes on or flashes. In this case, immediately stop the v ehicle in a
safe place, and check the engine after it has cooled completely . (P. 703)

5296-1. Using the air conditioning system and defogger
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
6
Interior features
QHeating
O In HV mode, the gasoline engine may operate in order to extract heat from
the engine coolant via the heater.
O 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 h eat
exchanger by operating the Remote Air Conditioning System befor e 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.
O 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
Q 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.
• 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

5797-2. Maintenance
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
7
Maintenance and care
QWhere 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.
QDoes 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:
OEngine missing, stumbling or pinging
OAppreciable loss of power
OStrange engine noises
OA fluid leak under the vehicle (However, water dripping from the air condi-
tioning system after use is normal.)
OChange in exhaust sound (This may indicate a dangerous carbon monoxide
leak. Drive with the windows open and have the exhaust system checked
immediately.)
OFlat-looking tires, excessive tire squeal when cornering, uneven tire wear
OVehicle pulls to one side when driven straight on a level road
OStrange noises related to suspension movement
OLoss of brake effectiveness, spongy feeling brake pedal, pedal almost
touches the floor, vehicle pulls to one side when braking
OEngine coolant temperature continually higher than normal (P. 659, 703)
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.

5927-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
QCoolant selection
Only use “Toyota Super Long Life Coolant” or a similar high qua lity ethylene
glycol based non-silicate, non-am ine, non-nitrite, and non-borate coolant with
long-life hybrid organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant an d 50% deion-
ized water. (Minimum temperature: -35 C [-31F])
For more details about coolant, contact any authorized Toyota r etailer or
Toyota authorized repairer, or any reliable repairer.
Q 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 any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer, test the cap and chec k for leaks in the
cooling system.
WARNING
Q 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 cool ant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
Q 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 coola nt label.
Q If you spill coolant
Be sure to wash it off with water to prevent it from damaging p arts or paint.

6568-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
If you think something is wrong
OFluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
O Flat-looking tires or uneven tire wear
O High coolant temperature warning light flashes or comes on
O Changes in exhaust sound
O Excessive tire squeal when cornering
O Strange noises related to the suspension system
O Pinging or other noises related to the hybrid system
O Engine missing, stumbling or running roughly
O Appreciable loss of power
O Vehicle pulls heavily to one side when braking
O Vehicle pulls heavily to one side when driving on a level road
O Loss of brake effectiveness, spongy feeling, pedal almost touches
the floor
If you notice any of the following symptoms, your vehicle proba -
bly needs adjustment or repair. Contact any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repaire r as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

6598-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
8
When trouble arises
(Flashes or illuminates)
PCS warning light
• When a buzzer sounds simultaneously:
Indicates a malfunction has occurred in the PCS (Pre-
Collision System).
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
• When a buzzer does not sound:
The PCS (Pre-Collision System) has become temporar-
ily unavailable, corrective action may be necessary.
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 366, 665)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
 P. 378
(Orange)
LTA indicator (warning buzzer)
Indicates a malfunction in the LTA (Lane Tracing Assist)
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 394)
Slip indicator light
Indicates a malfunction in:
• The VSC system;
• The TRC system; or
• The hill-start assist control system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
The light will flash when the ABS, VSC or TRC system is
operating.
High coolant temperature 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. 703)
• When the light comes on without flashing:
Indicates a malfunction in the exhaust heat recirculator
system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
Warning lightWarning light/Details/Actions

7038-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
8
When trouble arises
If your vehicle overheats
QIf the high coolant temperature warning light comes on or
flashes
Stop the vehicle in a safe place and turn off the air condition ing
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 t he
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 following may indicate that your vehicle is overheating.
O The high coolant temperature warning light (P. 659) comes on
or flashes, or a loss of hybrid system power is experienced. (F or
example, the vehicle speed does not increase.)
O “Hybrid System Overheated” is shown on the multi-information
display.
O Steam comes out from under the hood.
Correction procedures
1
2
3
1
2

7048-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
The coolant level is satisfactory if it is between the “MAX” and
“MIN” lines on the reservoir.
Reservoir
“MAX” line
“MIN” 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 temperature setting is adjusted to “L O” and
“A/C” switch ( ) is turned on immediately after a cold start. Co n-
firm 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 ( ) on and off
repeatedly. (The fans may not oper ate 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 repaire r.
4
1
2
3
5
6
7

7068-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47E75E_(EE)
After stopping the hybrid system and waiting for 5 minutes or
more, start the hybrid system again and check if “Hybrid System
Overheated” is shown on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repaire r.
If the message is not displayed:
The hybrid system temperature has dropped and the vehicle may
be driven normally.
However, if the message appears again frequently, contact any a utho-
rized Toyota retailer or Toyota authorized repairer, or any rel iable
repairer.
WARNING
Q To prevent an accident or injury when inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
O 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.
O After the hybrid system has been turned off, check that the “Accessory”,
“Ignition ON” or mileage display ( P. 213) on the main display and the
“READY” indicator are off.
When the hybrid system is operating, the gasoline engine may au tomati-
cally start, or the cooling fans may suddenly operate even if t he gasoline
engine stops. Do not touch or approach rotating parts such as t he fan,
which may lead to fingers or clothing (especially a tie, a scar f or a muffler)
getting caught, resulting in serious injury.
O Do not loosen the coolant reservoir caps while the hybrid system and radi-
ator are hot.
High temperature steam or coolant could spray out.
6