2021 TOYOTA PRIUS overheating

114
PRIUS_OM_OM47E09U_(U)
2. Instrument cluster
■BSM (Blind Spot Monitor) outsid e rear view mirror indicators
(if equipped) ( P. 349)
• 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. 656)

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PRIUS_OM_OM47E09U_(U)
4-1. Before driving
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the
shift lever or depress the accelerator pedal, this could cause an accident or
fire due to hybrid system overheating. Additionally, if the vehicle is parked in
a poorly ventilated area, exhaust gases may collect and enter the vehicle,
leading to death or a serious health hazard.
■ When braking
● When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this ma y cause
one side of the vehicle to brake differently than the other sid e. Also, the
parking brake may not securely hold the vehicle.
● If the electronically controlled assist function does not opera te, do not fol-
low other vehicles closely and avoid downhill or sharp turns th at require
braking.
In this case, braking is still possible, but the brake pedal sh ould be
depressed more firmly than usual. Also, the braking distance wi ll increase.
Have your brakes fixed immediately.
● The brake system consists of 2 or more individual hydraulic systems; if
one of the systems fails, the other(s) will still operate. In t his case, the
brake pedal should be depressed more firmly than usual and the braking
distance will increase. Have your brakes fixed immediately.
■ If the vehicle becomes stuck (AWD models)
Do not spin the wheels excessively when any of the tires is up in the air, or
the vehicle is stuck in sand, mud, etc. This may damage the driveline com-
ponents or propel the vehicle forward or backward, causing an a ccident.

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PRIUS_OM_OM47E09U_(U)
4-2. Driving procedures
Parking brake
To set the parking brake, fully
depress the parking brake pedal
with your left foot while depress-
ing the brake pedal with your right
foot.
(Depressing the pedal again
releases the parking brake.)
■Parking the vehicle
P. 228
■ Parking brake engaged warning buzzer
A buzzer will sound if the vehicle is driven with the parking b rake engaged.
“Release Parking Brake” is displayed on the multi-information d isplay (with
the vehicle reached a speed of 3 mph [5 km/h]).
■ Usage in winter time
P. 431
Operating instructions
(U.S.A.)
(Canada)
NOTICE
■ Before driving
Fully release the parking brake.
Driving the vehicle with the parking brake set will lead to bra ke components
overheating, which may affect braking performance and increase brake
wear.

424
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■Operating conditions of Active Cornering Assist
The system operates when the following occurs.
●TRAC/VSC can operate
● The driver is attempting to accelerate while turning
● The system detects that the vehicle is drifting to the outer si de
● The brake pedal is released
■ Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the s ystem from
overheating when there is frequent steering input over an exten ded period of
time. The steering wheel may feel heavy as a result. Should thi s occur, refrain
from excessive steering input or stop the vehicle and turn the hybrid system
off. The EPS system should return to normal within 10 minutes.
■ Electric power steering system wa rning light (warning buzzer)
P. 593
■ When a message related to AWD system is displayed on the multi-infor-
mation display (AWD models)
Perform the following actions.
MessageDetailsActions
“AWD System Overheated
Switching to 2WD Mode”AWD system is over-
heating.Stop the vehicle for a
certain amount of time
or drive the vehicle at
approximately 6 mph
(10 km/h) or more to
reduce the overload to
the system. Once the
display message on the
multi-information dis-
play turns off, there is
no problem continuing
to drive.
“AWD System Overheated 2WD Mode Engaged”
The vehicle switched
from all-wheel drive
(AWD) to front wheel
drive due to over-
heating.
“AWD System Malfunction
2WD Mode EngagedVisit Your Dealer”
A malfunction
occurred in the AWD
system, and the
vehicle switched to
front wheel drive.
Have the vehicle
inspected by your Toy-
ota dealer immediately.

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PRIUS_OM_OM47E09U_(U)
7-2. Steps to take in an emergency
If your vehicle overheats
■If the high coolant temperature warning light comes on or
flashesStop 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 t he
hoses and radiator core (ra diator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light ( P. 594) comes on
or flashes, or a loss of hybrid system power is experienced. (F or
example, the vehicle s peed does not increase.)
● “Hybrid System Overheated” is shown on the multi-information
display.
● Steam comes out from under the hood.
Correction procedures
1
2
3
1
2

727Alphabetical index
PRIUS_OM_OM47E09U_(U)
CleaningAluminum wheels.................. 497
Exterior ................................. 496
Front camera ........................ 291
Hybrid battery (traction
battery) air intake vent ........ 551
Interior................................... 502
Radar sensor ........................ 290
Seat belts .............................. 503
Water-repellent coating......... 497
Clock ........................................... 98
Adjustment ............................ 103
Coat hooks ............................... 486
Combination meter .................... 98 Clock adjustment .................. 103
Main display .......................... 115
Multi-information display ....... 124
Warning lights and indicators ............................ 107
Condenser ................................ 524
Console box ............................. 462
Consumption screen ....... 165, 172
Coolant ..................................... 522
Capacity ................................ 670
Checking ............................... 522
Preparing and checking before winter....................... 430
Cooling system ........................ 522 Engine overheating ............... 656
Hybrid system overheating ... 658
Cruise control Cruise control........................ 342
Dynamic radar cruise control with full-speed range .......... 326
Cup holders.............................. 463
Curtain shield airbags ............... 35
Customizable features ............ 690 Daytime running light
system.................................... 266
Deck board ............................... 467
Defogger Outside rear view
mirrors ........................ 440, 450
Rear window ................. 440, 450
Windshield .................... 440, 450
Dimension ................................ 664
Dinghy towing.......................... 244
Display BSM (Blind Spot Monitor) ..... 349
Drive information .................. 126
Dynamic radar cruise control with full-speed range .......... 326
Energy monitor ..... 127, 165, 172
Head-up display.................... 158
Intuitive parking assist .......... 363
LTA (Lane Tracing Assist) .... 316
Main display.......................... 115
Multi-information display ....... 124
Parking Support Brake function............................... 379
RCTA detection screen ........ 349
RSA (Road Sign Assist) ....... 323
S-APGS (Simple Advanced Parking Guidance
System) .............................. 390
Pre-collision warning ............ 297
Trip information..................... 119
Warning messages ............... 603
Do-it-yourself maintenance .... 512
Door courtesy lights ............... 458 Location ................................ 458
Wattage ................................ 674D
*: Refer to “MULTIMEDIA OWNER’S MANUAL”.

729Alphabetical index
PRIUS_OM_OM47E09U_(U)
Engine....................................... 666Accessory mode ................... 247
Compartment ........................ 518
Engine switch (power switch) ................................ 245
Exhaust gas precautions ........ 54
Hood ..................................... 515
How to start the hybrid system ......... ....................... 245
Identification number ............ 666
If the hybrid system will not start .............................. 645
If your vehicle has to be stopped in an emergency ... 581
Ignition switch (power switch) ................................ 245
Overheating .......................... 656
Power switch......................... 245
Engine coolant ......................... 522 Capacity ................................ 670
Checking ............................... 522
Preparing and checking before winter....................... 430
Engine oil ................................. 519 Capacity ................................ 668
Checking ............................... 519
Oil pressure warning light ..... 592
Preparing and checking before winter....................... 430
Engine switch (power
switch) .................................... 245 Auto power off function ......... 247
Automatic hybrid system shut off feature ........................... 249
Changing the power switch modes................................. 247
If your vehicle has to be stopped in an emergency ... 581
Starting the hybrid system .... 245 EPS (Electronic Power
Steering) ................................ 421
Function ................................ 421
Warning light......................... 593
EV drive mode ......................... 252
EV indicator ............................. 129
Event data recorder (EDR)........ 11
Exhaust gas precautions .......... 54
Flat tire ............................. 611, 631
Floor mat .................................... 26
Fluid Brake .................................... 671
Transmission ........................ 671
Washer ................................. 530
Fog lights ................................. 273
Replacing light bulbs ............ 577
Switch ................................... 273
Footwell lights ......................... 458
Front camera............................ 289
Front doors .............................. 185
Front fog lights ........................ 273
Replacing light bulbs ............ 577
Switch ................................... 273
Front passenger occupant classification system .............. 49
Front passenger’s seat belt reminder light ........................ 595
Front seat concentrated
airflow mode
(S-FLOW) ....................... 438, 448
Front seats ............................... 204
Adjustment............................ 204
Cleaning ............................... 502
Correct driving posture ........... 28
Head restraints ..................... 209
Seat heaters ......................... 456
Front side marker lights ......... 263
Light switch ........................... 263
Replacing light bulbs ............ 571
Wattage ................................ 674
F

730Alphabetical index
PRIUS_OM_OM47E09U_(U)
Front turn signal lights ........... 261Replacing light bulbs............. 577
Turn signal lever ................... 261
Fuel ........................................... 675 Capacity ................................ 667
Fuel gauge ............................ 116
Information ............................ 675
Refueling............................... 283
Type ...................................... 667
Warning light ......................... 594
Fuel consumption............ 133, 170
Fuel filler door.......................... 283
Opener .................................. 285
Refueling............................... 283
When the fuel filler door cannot be opened............... 286
Fuses ........................................ 563
Garage door opener ................ 488
Glove box ................................. 462
Hands-free system (for
cellular phone)
*
Head restraints ........................ 209
Head-up display ....................... 158
Headlights ................................ 263 AHB (Automatic High Beam) ................................. 268
Headlight aim ................ 566, 716
Light switch ........................... 263
Replacing light bulbs............. 577
Heated steering wheel............. 456
Heaters Automatic air conditioning
system ....... ................. 436, 446
Heated steering wheel .......... 456
Outside rear view mirrors ........................ 440, 450
Seat heaters ......................... 456 High coolant temperature
warning light.......................... 594
High mounted stoplight Replacing.............................. 577
High-voltage components ........ 88
Hill-start assist control ........... 421
Hood ......................................... 515
Hooks
Cargo hooks ......................... 468
Coat hooks ........................... 486
Grocery bag hook ................. 469
Retaining hooks (floor mat) .... 26
Horn .......................................... 212
Hybrid battery (tr action battery)
Air intake vent ......................... 89
Location .................................. 88
Specification ......................... 667
Hybrid battery (traction battery) air intake vent............ 89 Cleaning ............................... 551
Hybrid system............................ 84 Brake Override System ........ 229
Drive-Start Control ................ 230
Emergency shut off system .... 89
Energy monitor/consumption
screen ................ 127, 165, 172
EV drive mode ...................... 252
High voltage components ....... 88
Hybrid System Indicator ....... 129
Hybrid system precautions ..... 88
Hybrid vehicle driving tips ..... 427
If the hybrid system will not start .................................... 645
Overheating .......................... 656
Power switch ........................ 245
Regenerative braking ............. 86
Starting the hybrid system .... 245
Vehicle proximity notification system .......... ..................... ... 85
Hybrid System Indicator ......... 129
Hybrid transmission................ 255
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