TOYOTA PRIUS 2021 Owners Manual (in English)

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7
When trouble arises
7-2. 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

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7-2. Steps to take in an emergency
If a warning light turns on or a war ning
buzzer sounds
Calmly perform the following actions if any of the warning ligh ts
comes on or flashes. If a light comes on or flashes, but then
goes off, this does not necessarily indicate a malfunction in the
system. However, if this continues to occur, have the vehicle
inspected by your Toyota dealer.
Warning light and w arning buzzer list
Warning lightWarning light/Details/Actions
(U.S.A.)
(Canada)
Brake system warning light and warning buzzer (red
indicator)
*1
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
 Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer. Continuing to drive the vehi-
cle may be dangerous.
Brake system warning light (yellow indicator)
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system
 Have the vehicle inspected by your Toyota dealer
immediately.
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
 Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
Low engine oil pressure warning light
(warning buzzer)
*2
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
(U.S.A.)
(Canada)
Malfunction indicator lamp Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system
 Have the vehicle inspected by your Toyota dealer
immediately.

5937-2. Steps to take in an emergency
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7
When trouble arises
SRS warning lightIndicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
 Have the vehicle inspected by your Toyota dealer
immediately.
(U.S.A.)
(Canada)
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
 Have the vehicle inspected by your Toyota dealer
immediately.
(Red/yellow)
Electric power steering system warning light (warning
buzzer)
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
 Have the vehicle inspected by your Toyota dealer
immediately.
(Flashes or
illuminates)
(If equipped)
PCS warning light
• When a buzzer sounds simultaneously:Indicates a malfunction has occurred in the PCS (Pre-
Collision System).
 Have the vehicle inspected by your Toyota dealer
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 dis played on the multi-infor-
mation display. ( P. 294, 608)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
 P. 306
(Orange)
(If equipped)
LTA indicator (warning buzzer)
Indicates a malfunction in the LTA (Lane Tracing Assist)
 Follow the instructions dis played on the multi-infor-
mation display. ( P. 321)
Warning lightWarning light/Details/Actions

5947-2. Steps to take in an emergency
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Slip indicator lightIndicates a malfunction in:
• The VSC system;
• The TRAC system; or
• The hill-start assist control system
 Have the vehicle inspected by your Toyota dealer
immediately.
The light will flash when the ABS, VSC or TRAC 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. 656)
• When the light comes on without flashing: Indicates a malfunction in the exhaust heat recirculator
system
 Have the vehicle inspected by your Toyota dealer
immediately.
(Flashes)
(If equipped)
PKSB OFF indicator
Indicates a malfunction in the Parking Support Brake func-
tion
 Have the vehicle inspected by your Toyota dealer.
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. 375)
• The light will come on when the Parking Support Brake function is operating ( P. 379)
• The light will flash when the system cannot be temporar- ily used ( P. 383)
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 1.7 gal.
(6.4 L, 1.4 Imp.gal.) or less
 Refuel the vehicle.
Warning lightWarning light/Details/Actions

5957-2. Steps to take in an emergency
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7
When trouble arises
Driver’s and front passenger’s seat belt reminder light
(warning buzzer)
*4
Warns the driver and/or front passenger to fasten their
seat belts
 Fasten the seat belt.
If the front passenger’s seat is occupied, the front
passenger’s seat belt also needs to be fastened to
make the warning light (warning buzzer) turn off.
(U.S.A.)
(Canada)
Rear passengers’ seat belt reminder lights (warning
buzzer)
*5
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.
Master warning light
A buzzer sounds and the warning light comes on and
flashes to indicate that the master warning system has
detected a malfunction.
 P. 603
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 5 9 9 )
• Flat tire ( P. 611, 631)
 Adjust the tire inflation pressure to the specified
level.
The light will turn off after a few minutes. In case
the light does not turn off even if the tire inflation
pressure is adjusted, have the system checked by
your Toyota dealer.
When the light comes on after blinking for 1 minute:
Malfunction in t he tire pressure warning system
(  P. 5 9 9 )
 Have the system checked by your Toyota dealer.
(Flashes)
(If equipped)
“AFS OFF” indicator
Indicates a malfunction in the adaptive front-lighting sys-
tem
 Have the vehicle inspected by your Toyota dealer
immediately.
Warning lightWarning light/Details/Actions

5967-2. Steps to take in an emergency
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Brake Override System/Drive-Start Control/
Parking Support Brake function (symbol display)
*6
Brake Override SystemIndicates that the accelerator and brake pedals are being
depressed simultaneously, and the Brake Override Sys-
tem is operating
 Release the accelerator pedal and depress the brake
pedal.
Indicates a malfunction in the Brake Override System
(with warning buzzer)
 Have the vehicle inspected by your Toyota dealer
immediately.
Drive-Start Control Indicates that the shift position was changed and Drive-
Start Control was operated while depressing the accelera-
tor pedal (with warning buzzer)
 Momentarily release the accelerator pedal.
Indicates a malfunction in the Drive-Start Control (with
warning buzzer)
 Have the vehicle inspected by your Toyota dealer
immediately.
Parking Support Brake function Indicates that the Parking Support Brake function (if
equipped) is operating ( P. 379)
 Follow the instruction that is displayed on the multi-
information display.
(Canada only)
Low engine oil pressure warning (symbol display)*6
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
Warning lightWarning light/Details/Actions

5977-2. Steps to take in an emergency
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7
When trouble arises
*1: Brake system warning buzzer:When there is a possible problem that could affect braking perf ormance,
the warning light will come on and a warning buzzer will sound.
*2: Low engine oil pressure warning buzzer: A buzzer also sounds continuously for approximately 30 seconds at maxi-
mum in addition to the low engine oil pressure warning light when the
“READY” indicator is illuminated.
*3: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is
not fully closed (with the vehicle having reached a speed of 3 mph [5 km/h]).
*4: Driver’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to alert the drive r that his or
her seat belt is not fastened. Once the power switch is turned to ON mode,
the buzzer sounds. If the seat belt is still unfastened, the bu zzer sounds
intermittently for a certain period of time after the vehicle r eaches a certain
speed.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front
passenger that his or her seat belt is not fastened. If the sea t belt is unfas-
tened, the buzzer sounds intermittently for a certain period of time after the
vehicle reaches a certain speed.
*5: Rear passengers’ seat belt warning buzzer: The rear passengers’ seat belt warning buzzer sounds to alert t he rear
passenger that his or her seat belt is not fastened. If the sea t belt is unfas-
tened, the buzzer sounds intermittently for a certain period of time, after
the seat belt is fastened and unfastened and the vehicle reache s a certain
speed.
*6: This symbol is displayed on the multi-information display.

5987-2. Steps to take in an emergency
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■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors (front door), side impact sensors (front), side
impact sensors (rear), driver’s seat belt buckle switch, front passenger occu-
pant classification system (ECU and sensors), “AIR BAG ON” indi cator light,
“AIR BAG OFF” indicator light, front passenger’s seat belt buck le switch, seat
belt pretensioners, airbags, interconnecting wiring and power s ources.
( P. 35)
■ Front passenger detection sensor, seat belt reminder and warnin g
buzzer
● If luggage is placed on the front passenger seat, the front pas senger detec-
tion sensor may cause the warning light to flash and the warnin g buzzer to
sound even if a passenger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passenger,
and the warning light may not operate properly.
■ Electric power steering system wa rning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the vol tage tempo-
rarily drops, the electric power steering system warning light may come on
and the warning buzzer may sound.
■ If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
● Is the fuel tank cap loose?
If it is, tighten it securely.
The malfunction indicator lamp will go off after several drivin g trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.

5997-2. Steps to take in an emergency
PRIUS_OM_OM47E09U_(U)
7
When trouble arises
■When the tire pressure warning light comes on
Inspect the appearance of the tire to check that the tire is not punctured.
If the tire is punctured: P. 611, 631
If the tire is not punctured:
Check the tire inflation pressure and adjust to the appropriate level. Initial-
izing the tire pressure warning system will not turn off the tire pressure
warning light.
■The tire pressure warning light may come on due to natural caus es
The tire pressure warning light may come on due to natural caus es such
as natural air leaks and tire inflation pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure w ill turn off the
warning light (afte r a few minutes).
■When a tire is replace d with a spare tire
Vehicles with compact spare tire : The compact spare tire is not equipped
with a tire pressure warning valve and transmitter. If a tire g oes flat, the
tire pressure warning light will not turn off even though the flat tire has
been replaced with the spare tire . Replace the spare tire with the repaired
tire and adjust the tire inflation pressure. The tire pressure warning light
will go off after a few minutes.
Vehicles with full-size spare tire: The spare tire is also equi pped with a tire
pressure warning valve and transmitter. The tire pressure warning light
will turn on if the tire inflatio n pressure of the spare tire i s low. If a tire goes
flat, the tire pressure warnin g light will not turn off even th ough the flat tire
has been replaced with the spare tire. Replace the spare tire w ith the
repaired tire and adjust the tire inflation pressure. The tire pressure warn-
ing light will go off a fter a few minutes.
■Conditions that the tire pressure warning system may not functi on
properly
 P. 5 3 8
■If the tire pressure warning light frequently comes on after bl inking
for 1 minute
If the tire pressure warning light frequently comes on after bl inking for
1 minute when the power switch is turned to ON mode, have it che cked
by your Toyota dealer.
■ Warning buzzer
In some cases, the buzzer may not be heard due to being in a no isy location
or audio sound.

6007-2. Steps to take in an emergency
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WARNING
■When the electric power steering system warning light comes on
When the light comes on yellow, the assist to the power steerin g is
restricted. When the light comes on red, the assist to the powe r steering is
lost and handling operations of the steering wheel become extre mely
heavy. When steering wheel operations are heavier than usual, g rip the
steering wheel firmly and operate it using more force than usua l.
■
If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could
cause a loss of vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust t he tire
inflation pressure immediately.
●Vehicles with emergency tire puncture repair kit: If the tire p ressure
warning light comes on even after tire inflation pressure adjus tment, it
is probable that you have a flat tire. Check the tires. If a ti re is flat,
repair the flat tire by using emergency tire puncture repair ki t.
●Vehicles with spare tire: If the tire pressure warning light co mes on
even after tire inflation pressure adjustment, it is probable that you
have a flat tire. Check the tires. If a tire is flat, change it with the spare
tire and have the flat tire repaired by the nearest Toyota deal er.
●Avoid abrupt maneuvering and braking. If the vehicle tires dete riorate,
you could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.