engine overheat TOYOTA PRIUS 2021 Owners Manual (in English)

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PRIUS_OM_OM47E09U_(U)
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6-3. Do-it-yourself maintenance
Do-it-yourself service precautions ..................... 512
Hood.................................. 515
Positioning a floor jack ...... 517
Engine compartment ......... 518
Tires .................................. 532
Tire inflation pressure........ 542
Wheels .............................. 545
Air conditioning filter .......... 548
Cleaning the hybrid battery (traction battery) air intake
vent and filter .................. 551
Wiper insert replacement .................... 556
Electronic key battery ........ 560
Checking and replacing fuses ............................... 563
Headlight aim .................... 566
Light bulbs ......................... 568
7-1. Essential information Emergency flashers .......... 580
If your vehicle has to be stopped in an
emergency ...................... 581
If the vehicle is trapped in rising water...................... 582 7-2. Steps to take in an
emergency
If your vehicle needs to be towed .......................... 584
If you think something is wrong............................... 591
If a warning light turns on or a warning buzzer
sounds ............................. 592
If a warning message is displayed ......................... 603
If you have a flat tire (vehicles without
spare tire) ........................ 611
If you have a flat tire (vehicles with
spare tire) ........................ 631
If the hybrid system will not start ........................... 645
If the electronic key does not operate properly ........ 647
If the 12-volt battery is discharged ....................... 650
If your vehicle overheats.... 656
If the vehicle becomes stuck ................................ 661
7When trouble arises

17Pictorial index
PRIUS_OM_OM47E09U_(U)Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 275
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . P. 430
Precautions against car wash (vehicles with rain-sensing
windshield wipers) . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . P. 498
Replacing the wiper insert . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 556
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 283
Refueling method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 283
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 667
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 532
Tire size/inflation pressure . . . . . . . . . . . . . . . . . . . . . . . . . P. 672
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 430
Checking/rotation/tire pressur e warning system . . . . . . . . .P. 532
Coping with flat tires . . . . . . . . . . . . . . . . . . . . . . . . . . P. 611, 631
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 515
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 515
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 668
Coping with overheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 656
Headlights/daytime running lights . . . . . . . . . . . . . . . . . . . . P. 263
Parking lights/front side marker lights/
LED accent lights
*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 263
Fog lights
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 273
Turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 261
Tail lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 263
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 263
Back-up lights
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 255
Rear side maker lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 263
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5
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7
Light bulbs of the exterior lights for driving
(Replacing method: P. 568, Watts: P. 674)
*: If equipped
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9
10
11
12
13
14
15

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 driving the vehicle
● Use engine braking (shift position B instead of shift position D) to maintain
a safe speed when driving down a steep hill.
Using the brakes continuously may cause the brakes to overheat and lose
effectiveness. ( P. 256)
● Do not adjust the positions of the steering wheel, the seat, or the inside or
outside rear view mirrors while driving.
Doing so may result in a loss of vehicle control.
● Always check that all passengers’ arms, head or other parts of their body
are not outside the vehicle.
● AWD models: Do not drive the vehicle off-road.
This is not an AWD vehicle designed for off-road driving. Proce ed with all
due caution if it becomes unavoidable to drive off-road.
● Do not drive across river crossings or through other bodies of water.
This may cause electric/electronic components to short circuit, damage
the hybrid system or cause other serious damage to the vehicle.
● Do not drive in excess of the speed limit. Even if the legal sp eed limit per-
mits it, do not drive over 85 mph (140 km/h) unless your vehicl e has high-
speed capability tires. Driving over 85 mph (140 km/h) may resu lt in tire
failure, loss of control and possible injury. Be sure to consult a tire dealer
to determine whether the tires on your vehicle are high-speed c apability
tires or not before driving at such speeds.
■ When driving on slippery road surfaces
● Sudden braking, acceleration and steering may cause tire slippa ge and
reduce your ability to control the vehicle.
● Sudden acceleration, engine braking due to shifting, or changes in engine
speed could cause the vehicle to skid, resulting in an accident .
● After driving through a puddle, depress the brake pedal to make sure that
the brakes are functioning properly. Wet brake pads may prevent the
brakes from functioning properly. If the brakes on only one sid e are wet
and not functioning properly, steering control may be affected.

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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.
■If you hear a squealing or scrap ing noise (brake pad wear limit indica-
tors)
Have the brake pads checked and replaced by your Toyota dealer as soon
as possible.
Rotor damage may result if the pads are not replaced when needed.
It is dangerous to drive the vehicle when the wear limits of the brake pads
and/or those of the brake discs are exceeded.
■ When the vehicle is stopped
● Do not depress the accelerator pedal unnecessarily.
If the shift position is in any position other than P or N, the vehicle may
accelerate suddenly and unexpectedly, causing an accident.
● In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while stopped with the “READY” indic ator is
illuminated, and apply the parking brake as necessary.
● If the vehicle is stopped on an incline, in order to prevent ac cidents caused
by the vehicle rolling forward or backward, always depress the brake pedal
and securely apply the parking brake as needed.
● Avoid revving or racing the engine.
Running the engine at high speed while the vehicle is stopped m ay cause
the exhaust system to overheat, which could result in a fire if combustible
material is nearby.

6087-2. Steps to take in an emergency
PRIUS_OM_OM47E09U_(U)■
If “Shift to Before Exiting Vehicle” is shown
Message is displayed when the driver’s door is opened without t urning the
power switch to off with the shift position in any position oth er than P.
Shift the shift position to P.
■ If “Shift is in Release Accelerat or Before Shifting” is shown
Message is displayed when the accelerator pedal has been depressed and
the shift position is in N.
Release the accelerator pedal and shift the shift position to D or R.
■ If “Depress Brake When Vehicle is Stopped. Hybrid System may Ov er-
heat.” is shown
The message may be shown when the accelerator pedal is depresse d to hold
the vehicle while the vehicle is stopped on an uphill, etc.
The hybrid system may overheat. Release the accelerator pedal a nd depress
the brake pedal.
■ If “Shifted to Stop Vehicle to Shift to ” is shown
If the P position switch is pressed while driving, the shift po sition is changed
to N and the message is shown. ( P. 257)
■ If “Auto Power OFF to Conserve Battery” is shown
The power switch has been turned off by the automatic power off function.
When starting the hybrid system next time, operate the hybrid s ystem for
approximately 5 minutes to recharge the 12-volt battery.
■ If “Engine Oil Level Low Add or Replace” is displayed
The engine oil level may be low. Check the level of the engine oil, and add
engine oil if necessary. This message may be displayed if the vehicle is
stopped on a slope. Move the vehicle to a level surface and che ck if the mes-
sage disappears.
■ If “Accelerator and Brake Pedals Pressed Simultaneously” is sho wn
The accelerator and brake pedals are being depressed simultaneo usly.
( P. 229)
Release the accelerator pedal and depress the brake pedal.
■ If a message that indicates the malfunction of front camera is dis-
played.
*
The following systems may be suspended until the problem shown in the
message is resolved. ( P. 294, 592)
● PCS (Pre-Collision System)
*
●LTA (Lane Tracing Assist)*
●AHB (Automatic High Beam)*
●RSA (Road Sign Assist)*
●Dynamic radar cruise control with full-speed range*
*
: If equipped

6597-2. Steps to take in an emergency
PRIUS_OM_OM47E09U_(U)
7
When trouble arises
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 d oes not disappear:
Stop the hybrid system and contact your Toyota dealer.
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 your To y o t a
dealer.
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 ho od 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. 116) 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 the 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 scarf or a muffler)
getting caught, resulting in serious injury.
● Do not loosen the coolant reservoir caps while the hybrid syste m and radi-
ator are hot.
High temperature steam or coolant could spray out.
6

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

733Alphabetical index
PRIUS_OM_OM47E09U_(U)
Multi-information display ........ 124Air conditioning system
settings screen ................... 146
Audio system-linked display ................................ 145
Display contents ................... 124
Drive information................... 126
Driving assist system information.......................... 150
Dynamic radar cruise control with full-speed range .......... 326
Energy monitor ..................... 127
Intuitive parking assist .......... 363
Language .............................. 153
LTA (Lane Tracing Assist) .... 316
Navigation system-linked display ................................ 145
Parking Support Brake function ............................... 379
Pre-collision warning............. 297
RCTA detection screen......... 349
RSA (Road Sign Assist)........ 323
S-APGS (Simple Advanced
Parking Guidance
System) .............................. 390
Settings display..................... 151
Warning message display..... 150
Navigation system
*2
Noise from under vehicle............ 8
Odometer.................................. 119
Oil Engine oil .............................. 668 Opener
Back door ............................. 191
Fuel filler door ....................... 285
Garage door ......................... 488
Hood ..................................... 515
Outside rear view mirrors ....... 216 Adjustment............................ 216
BSM (Blind Spot Monitor) ..... 349
Folding .................................. 216
Outside rear view mirror defoggers ................... 440, 450
Outside temperature display.................................... 116
Overhead console ................... 465
Overheating ............................. 656
P position switch ..................... 256
Panic mode .............................. 181
Parking assist sensors
Intuitive parking assist .......... 362
Parking Support Brake function............................... 373
S-APGS (Simple Advanced Parking Guidance
System) .............................. 386
Parking brake........................... 262
Operation .............................. 262
Parking brake engaged warning buzzer ................... 262
Parking lights........................... 263 Light switch ........................... 263
Replacing light bulbs .... 570, 577
Wattage ................................ 674
Parking lock ............................. 256
PCS (Pre-Collision System).... 296 Enabling/disabling the system .......... ...................... 300
Function ................................ 296
Warning light......................... 593
N
O
P
*1: Refer to “MULTIMEDIA OWNER’S MANUAL”.
*2: Refer to “NAVIGATION S YSTEM OWNER’S MANUAL”.