warning light TOYOTA PRIUS 2022 Repair Manual

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PRIUS_OM_OM47F01U_(U)
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.

5897-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
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. 289, 605)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
 P. 301
(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. 316)
Warning lightWarning light/Details/Actions

5907-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
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. 652)
• 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. 372)
• The light will come on when the Parking Support Brake function is operating ( P. 376)
• The light will flash when the system cannot be temporar- ily used ( P. 378)
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

5917-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
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. 599
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 5 9 5 )
• Flat tire ( P. 607, 627)
 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 5 )
 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

5927-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
Inappropriate pedal operation warning light*6 (warning
buzzer) When a buzzer sounds:
Indicates a malfunction in:
• The Brake Override System
• The Drive-Start Control
 Have the vehicle inspected by your Toyota dealer
immediately.
Indicates that the shift position was changed and Drive-
Start Control was operated while depressing the accelera-
tor pedal.
 Momentarily release the accelerator pedal.
Indicates that the Parking Support Brake function (if
equipped) is operating ( P. 376)
 Follow the instruction that is displayed on the multi-
information display.
When a buzzer does not sound:
Indicates 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.
(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

5937-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
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.

5947-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
■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.

5957-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(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. 607, 627
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 4
■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.

5967-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
WARNING
■When the electric power steering system warning light comes on
When the light comes on yellow, the assist to the power steering is
restricted. When the light comes on red, the assist to the power steering is
lost and handling operations of the steering wheel become extre mely
heavy. When steering wheel operations are heavier than usual, grip 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 the 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 t hat 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.

5977-2. Steps to take in an emergency
PRIUS_OM_OM47F01U_(U)
7
When trouble arises
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly
when cold and inflated to the inflation pressure recommended by the
vehicle manufacturer on the vehicle placard or tire inflation p ressure
label (tire and load information label). (If your vehicle has t ires of a dif-
ferent size than the size indicated on the vehicle placard or t ire inflation
pressure label [tire and load information label], you should de termine
the proper tire inflation p ressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire
pressure monitoring system (TPMS -tire pressure warning system) that
illuminates a low tire pressure telltale (tire pressure warning light) when
one or more of your tires is significantly under-inflated. Acco rdingly,
when the low tire pressure telltale (tire pressure warning ligh t) illumi-
nates, you should stop and check your tires as soon as possible , and
inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire tread lif e, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a sub-
stitute for proper tire maintenance, and it is the driver’s res ponsibility to
maintain correct tire pressure, even if under-inflation has not reached
the level to trigger illumination of the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warn-
ing system) malfunction indicato r to indicate when the system is not
operating properly. The TPMS (tire pressure warning system) mal func-
tion indicator is combined with the low tire pressure telltale (tire pressure
warning light). When the system detects a malfunction, the tell tale will
flash for approximately one minute and then remain continuously illumi-
nated. This sequence will continue upon subsequent vehicle star t-ups
as long as the malfunction exists . When the malfunction indicator is illu-
minated, the system may not be able to detect or signal low tir e pres-
sure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a vari-
ety of reasons, including the installation of replacement or alternate tires
or wheels on the vehicle that prevent the TPMS (tire pressure w arning
system) from functioning properly. Always check the TPMS (tire pres-
sure warning system) malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the replacement or alter-
nate tires and wheels allow the TPMS (tire pressure warning system) to
continue to function properly.