2023 TOYOTA PRIUS coolant temperature

5837-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
7
When trouble arises
High coolant temperature warning light
(vehicles without exhaust heat recirculator system)
Indicates that the engine coolant temperature is too high
Changes from a flashing to a solid light when the engine
coolant temperature increases
 Immediately stop the vehicle in a safe place.
( P. 645)
High coolant temperature warning light
(vehicles with exhaust h eat recirculator system)
• 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. 645)
• 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.
(Flashes) (If equipped)
PKSB OFF indicator
Indicates a malfunction in the Parking Support Brake func-
tion
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer.
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will come on when the Parking Support Brake
function is turned off ( P. 396)
• The light will come on when the Parking Support Brake
function is operating ( P. 400)
• The light will flash when the system cannot temporarily
be used ( P. 402)
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 6.4 L
(1.7 gal., 1.4 Imp.gal.) or less
 Refuel the vehicle.
Warning lightWarning light/Details/Actions

6457-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
7
When trouble arises
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
any authorized Toyota retailer
or Toyota authorized repairer,
or any reliable repairer.
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light (P. 583) comes on
or flashes, or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
● “Hybrid System Overheated” is shown on the multi-information
display.
● Steam comes out from under the hood.
Correction procedures
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6477-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
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When trouble arises
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 air condi tioning system is turned on immedi-
ately 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 air con-
ditioning system on and off repeatedly. (The fans may not operate 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 repairer.
■If “Hybrid System Overheated” is shown on the multi-informa-
tion display
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, inspect the 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.
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6487-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
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.
If water was added in an emer-
gency, have the vehicle
inspected at any authorized
Toyota retailer or Toyota autho-
rized repairer, or any reliable
repairer as soon as possible.
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 repairer.
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 autho-
rized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
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6497-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
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When trouble arises
WARNING
■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.
● 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.
● After the hybrid system has been turned off, check that the “Accessory”,
“Ignition ON” or mileage display ( P. 118, 120) on the main display and
the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automati-
cally start, or the cooling fans may suddenly operate even if the gasoline
engine stops. Do not touch or approach rotating parts such as the fan,
which may lead to fingers or clothing (especially a tie, a scarf or a muffler)
getting caught, resulting in serious injury.
● Do not loosen the coolant reservoir caps while the hybrid system and radi-
ator are hot.
High temperature steam or coolant could spray out.
NOTICE
■ When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently.
Adding cool coolant to a hot hybrid system too quickly can cause damage to
the hybrid system.
■ To prevent damage to the cooling system
Observe the following precautions:
● Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
● Do not use any coolant additive.

692Alphabetical index
PRIUS_OM_OM47F32E_(EE)
Fuel ........................................... 668
Capacity ................................ 657
Fuel gauge .................... 118, 120
Information ............................ 668
Refueling ............................... 277
Type ...................................... 657
Warning light ......................... 583
Fuel consumption ............ 136, 169
Fuel filler door .......................... 279
Opener .................................. 279
Refueling ............................... 277
When the fuel filler door
cannot be opened ............... 280
Fuses ........................................ 557
Glove box ................................. 474
Hands-free system (for
cellular phone)
*
Head restraints......................... 199
Head-up display ....................... 160
Headlights ................................ 261
AHB (Automatic High
Beam) ................................. 266
Automatic headlight
leveling ............................... 264
Extended Headlight
Lighting system................... 263
Light switch ........................... 261
Replacing light bulbs ............. 565
Heaters
Automatic air conditioning
system ................................ 458
Outside rear view mirrors ...... 463
Seat heaters.......................... 468
High coolant temperature
warning light .......................... 583
High mounted stoplight
Replacing .............................. 565High-voltage components ........ 84
Hill-start assist control............ 442
Hood ......................................... 511
Hooks
Cargo hooks ......................... 480
Coat hooks............................ 493
Grocery bag hook ................. 481
Retaining hooks (floor mat)..... 30
Horn .......................................... 203
Hybrid battery (traction battery)
Air intake vent ......................... 85
Location .................................. 84
Specification ......................... 657
Hybrid battery (traction
battery) air intake vent ............ 85
Cleaning................................ 545
Hybrid system ............................ 79
Brake Override System......... 221
Drive-Start Control ................ 222
Emergency shut off system .... 85
Energy monitor/consumption
screen......................... 130, 166
EV drive mode ...................... 250
High voltage components ....... 84
Hybrid System Indicator........ 132
Hybrid system precautions ..... 84
Hybrid vehicle driving tips ..... 449
If the hybrid system will not
start .................................... 634
Overheating .......................... 645
Power switch......................... 244
Regenerative braking.............. 81
Starting the hybrid system .... 244
Vehicle proximity notification
system .................................. 80
Hybrid System Indicator ......... 132
Hybrid transmission ................ 253
G
H

701Alphabetical index
PRIUS_OM_OM47F32E_(EE)
Warning buzzers
Approach warning ................. 339
Brake system ........................ 580
LTA (Lane Tracing Assist) .... 312
Open door ..................... 180, 583
Parking Support Brake
function ............................... 400
Pre-collision warning ............. 297
Radar cruise control .............. 339
RCTA (Rear Crossing Traffic
Alert) ................................... 356
Seat belt reminder................. 584
Shift position ......................... 255
Toyota parking
assist-sensor ...................... 385Warning lights.......................... 110
ABS....................................... 581
Brake Override System......... 585
Brake system ........................ 580
Charging system ................... 580
Drive-Start Control ................ 585
Driver’s seat belt reminder
light..................................... 584
Electronic engine control
system ................................ 581
Electric power steering
system ................................ 581
Front passenger’s seat belt
reminder light...................... 584
High coolant temperature ..... 583
Low engine oil pressure ........ 581
Low fuel level ........................ 583
Malfunction indicator lamp .... 581
Master warning light.............. 584
Open door ............................. 583
Parking Support Brake
function ............................... 585
PCS ...................................... 582
PKSB OFF indicator ............. 583
Rear passengers’ seat belt
reminder light...................... 584
Seat belt reminder light ......... 584
Slip indicator ......................... 582
SRS ...................................... 581
Tire pressure......................... 584
W
*: Refer to “Navigation and multimedia system Owner’s manual”.