system malfunction TOYOTA PRIUS PRIME 2021 Owners Manual (in English)

PRIUS PRIME_OM_OM47D71U_(U)
Pictorial indexSearch by illustration
1For safety
and securityMake sure to read through them
2Plug-in hybrid
systemPlug-in hybrid system features, charging method,
etc.
3Instrument
clusterHow to read the gauges and meters, the variety of
warning lights and indicators, etc.
4Operation of
each componentOpening and closing the doors and windows,
adjustment before driving, etc.
5DrivingOperations and advice which are necessary for
driving
6Interior featuresUsage of the interior features, etc.
7Maintenance
and careCaring for your vehicle and maintenance
procedures
8When trouble
arisesWhat to do in case of malfunction or emergency
9Vehicle
specificationsVehicle specifications, customizable features, etc.
10For ownersReporting safety defects for U.S. owners, and seat
belt, SRS airbag and headlight aim instructions for
Canadian owners
IndexSearch by symptom
Search alphabetically

8
PRIUS PRIME_OM_OM47D71U_(U)
For your infor mation
Please note that this manual applies to all models and explains all equipment,
including options. Therefore, you may find some explanations for equipment
not installed on your vehicle.
All specifications provided in this manual are current at the time of printing.
However, because of the Toyota policy of continual product improvement, we
reserve the right to make changes at any time without notice.
Depending on specifications, the vehicle shown in the illustrations may differ
from your vehicle in terms of equipment.
Approximately five hours after the hybrid system is turned off, you may hear
sound coming from under the vehicle for several minutes. This is the sound of
a fuel evaporation leakage check and, it does not indicate a malfunction.
A wide variety of non-genuine spare parts and accessories for Toyota vehi-
cles are currently available in the market. You should know that Toyota does
not warrant these products and is not responsible for their performance,
repair, or replacement, or for any damage they may cause to, or adverse
effect they may have on, your Toyota vehicle.
This vehicle should not be modified with non-genuine Toyota products. Modi-
fication with non-genuine Toyota products could affect its performance, safety
or durability, and may even violate governmental regulations. In addition,
damage or performance problems resulting from the modification may not be
covered under warranty.
Main Owner’s Manual
Noise from under vehicle after turning off the hybrid system
Accessories, spare parts and modification of your Toyota

421-1. For safe use
PRIUS PRIME_OM_OM47D71U_(U)
WARNING
■SRS airbag precautions
●Do not hang coat hangers or other hard objects on the coat hooks. All of
these items could become projectiles and may cause death or serious
injury, should the SRS curtain shield airbags deploy.
●If a vinyl cover is put on the area where the SRS knee airbag will deploy,
be sure to remove it.
●Do not use seat accessories which cover the parts where the SRS side
airbags and SRS seat cushion airbag inflate as they may interfere with
inflation of the SRS airbags. Such accessories may prevent the side air-
bags and seat cushion airbag from activating correctly, disable the system
or cause the side airbags and seat cushion airbag to inflate accidentally,
resulting in death or serious injury.
●Do not strike or apply significant levels of force to the area of the SRS air-
bag components or the front doors.
Doing so can cause the SRS airbags to malfunction.
●Do not touch any of the component parts immediately after the SRS air-
bags have deployed (inflated) as they may be hot.
●Do not attach anything to or lean any-
thing against areas such as the dash-
board, steering wheel pad and lower
portion of the instrument panel.
These items can become projectiles
when the SRS driver, front passenger
and knee airbags deploy.
●Do not attach anything to areas such as
a door, windshield, side windows, front
or rear pillar, roof side rail and assist
grip.

431-1. For safe use
PRIUS PRIME_OM_OM47D71U_(U)
1
For safety and security
WARNING
■SRS airbag precautions
●If breathing becomes difficult after the SRS airbags have deployed, open a
door or side window to allow fresh air in, or leave the vehicle if it is safe to
do so. Wash off any residue as soon as possible to prevent skin irritation.
●If the areas where the SRS airbags are stored, such as the steering wheel
pad and front and rear pillar garnishes, are damaged or cracked, have
them replaced by your Toyota dealer.
●Do not place anything, such as a cushion, on the front passenger’s seat.
Doing so will disperse the passenger’s weight, which prevents the sensor
from detecting the passenger’s weight properly. As a result, the SRS front
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57004b00480003004800590048005100570003005200490003[a collision.
■Modification and disposal of SRS airbag system components
Do not dispose of your vehicle or perform any of the following modifications
without consulting your Toyota dealer. The SRS airbags may malfunction or
deploy (inflate) accidentally, causing death or serious injury.
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4b0048000300360035003600030044004c005500450044004a[s
●Repairs, modifications, removal or replacement of the steering wheel,
instrument panel, dashboard, seats or seat upholstery, front, side and rear
pillars, roof side rails, front door panels, front door trims or front door
speakers
●Modifications to the front door panel (such as making a hole in it)
●Repairs or modifications of the front fender, front bumper, or side of the
occupant compartment
●Installation of a grille guard (bull bars, kangaroo bar, etc.), snow plows,
winches or roof luggage carrier
●Modifications to the vehicle’s suspension system
●Installation of electronic devices such as mobile two-way radios and CD
players
●Modifications to your vehicle for a person with a physical disability

531-1. For safe use
PRIUS PRIME_OM_OM47D71U_(U)
1
For safety and security
■There is a malfunction in the system
*1: The system judges a person of adult size as an adult. When a smaller
adult sits in the front passenger seat, the system may not recognize him/
her as an adult depending on his/her physique and posture.
*2: In the event the front passenger is wearing a seat belt.
*3: In the event the front passenger does not wear a seat belt.
*4: For some children, child in seat, child in booster seat or child in convertible
seat, the system may not recognize him/her as a child. Factors which may
affect this can be the physique or posture.
*5: Never install a rear-facing child restraint system on the front passenger
seat. A forward-facing child restraint system should only be installed on the
front passenger seat when it is unavoidable. (P. 61)
*6: In case the indicator light is not illuminated, consult this manual on how to
install the child restraint system properly. (P. 58)
Indicator/
warning light
“AIR BAG ON” and “AIR BAG OFF”
indicator lights“AIR BAG OFF”
SRS warning lightOnSeat belt reminder light
Devices
Front passenger airbagDeactivated
Seat cushion airbag in the front passenger
sideDeactivated

551-1. For safe use
PRIUS PRIME_OM_OM47D71U_(U)
1
For safety and security
WARNING
■Front passenger occupant classification system precautions
●If an adult sits in the front passenger seat, the “AIR BAG ON” indicator
light is illuminated. If the “AIR BAG OFF” indicator is illuminated, ask the
passenger to sit up straight, well back in the seat, feet on the floor, and
with the seat belt worn correctly. If the “AIR BAG OFF” indicator still
remains illuminated, either ask the passenger to move to the rear seat, or
if that is not possible, move the front passenger seat fully rearward.
●When it is unavoidable to install a forward-facing child restraint system on
the front passenger seat, install the child restraint system on the front pas-
senger seat in the proper order. (P. 58)
●Do not modify or remove the front seats.
●Do not kick the front passenger seat or subject it to severe impact. Other-
wise, the SRS warning light may come on to indicate a malfunction of the
front passenger occupant classification system. In this case, contact your
Toyota dealer immediately.
●Child restraint systems installed on the rear seat should not contact the
front seatbacks.
●Do not use a seat accessory, such as a cushion and seat cover, that cov-
ers the seat cushion surface.
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510057000300560048004400570011[
●Adjust the front passenger seat so that the head restraint does not touch
the ceiling. If the head restraint is left in contact with the ceiling, the system
may not detect the front passenger properly, leading to improper operation
of the airbags.

781-3. Emergency assistance
PRIUS PRIME_OM_OM47D71U_(U)
■Safety Connect Services Information
●Phone calls using the vehicle’s Bluetooth® technology will not be possible
when Safety Connect is active and in use.
●Safety Connect is available beginning Fall 2009 on select Toyota models (in
the contiguous United States only). Contact with the Safety Connect
response center is dependent upon the telematics device being in operative
condition, cellular connection availability, and GPS satellite signal reception,
which can limit the ability to reach the response center or receive emer-
gency service support. Enrollment and Telematics Subscription Service
Agreement required. A variety of subscription terms is available; charges
vary by subscription term selected and location.
●Automatic Collision Notification, Emergency Assistance and Stolen Vehicle
Location are available in the United States, including Hawaii and Alaska,
Puerto Rico and Canada, and Enhanced Roadside Assistance are available
in the United States, Puerto Rico and Canada.
●Automatic Collision Notification, Emergency Assistance, Stolen Vehicle and
Enhanced Road Assistance are not available in the U.S. Virgin Islands.
For vehicles first sold in the U.S. Virgin Islands, no Safety Connect services
will function in or outside the U.S. Virgin Islands.
●Safety Connect services are not subject to section 255 of the Telecommuni-
cations Act and the device is not TTY compatible.
■Languages
The Safety Connect response center will offer support in multiple languages.
The Safety Connect system will offer voice prompts in English, Spanish, and
French. Please indicate your language of choice when enrolling.
■When contacting the response center
You may be unable to contact the response center if the network is busy.
When the power switch is turned to ON mode, the red indicator light
comes on for 2 seconds then turns off. Afterward, the green indicator
light comes on, indicating that the service is active.
The following indicator light patterns indicate specific system usage
conditions:
●Green indicator light on = Active service
●Green indicator light flashing = Safety Connect call in process
●Red indicator light (except at vehicle start-up) = System malfunction
(contact your Toyota dealer)
●No indicator light (off) = Safety Connect service not active
Safety Connect LED light Indicators

831-4. Theft deterrent system
PRIUS PRIME_OM_OM47D71U_(U)
1
For safety and security
Immobilizer system
The indicator light flashes after
the power switch has been turned
off to indicate that the system is
operating.
The indicator light stops flashing
after the power switch has been
turned to ACCESSORY or ON
mode to indicate that the system
has been canceled.
■System maintenance
The vehicle has a maintenance-free type immobilizer system.
■Conditions that may cause the system to malfunction
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4400030050004800570044004f004f004c0046000300520045[ject
●If the key is in close proximity to or touching a key registered to the security
system (key with a built-in transponder chip) of another vehicle
The vehicle’s keys have built-in transponder chips that prevent
the hybrid system from starting if a key has not been previously
registered in the vehicle’s on-board computer.
Never leave the keys inside the vehicle when you leave the vehi-
cle.
This system is designed to help prevent vehicle theft but does not
guarantee absolute security against all vehicle thefts.

96
PRIUS PRIME_OM_OM47D71U_(U)
2-1. Plug-in hybrid system
■If the vehicle is not used for a long time
●The 12-volt battery may discharge. In this event, charge the 12-volt battery.
(P. 607)
In order to prevent the hybrid battery (traction battery) from becoming
extremely low in charge, charge the hybrid battery (traction battery) from
external power source or start the hybrid system at least once every 2 or 3
months, and turn the power switch off after the gasoline engine has
stopped automatically. (If the gasoline engine does not start up even after
approximately 10 seconds have passed since the “READY” indicator came
on, the power switch can be turned to off without any further action.)
●When the vehicle is left with the charging cable connected, the electricity
consumption amount of the 12-volt battery increases due to controls, such
as the system checking, operating. When the charging cable is not needed,
immediately remove it from the vehicle.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to
move with the “READY” indicator is illuminated. For safety, apply the parking
brake and make sure to shift the shift position to P when parked.
The following sounds or vibrations may occur when the hybrid system is
operating and are not a malfunction.
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) when the
hybrid system starts or stops.
●Relay operating sounds such as a snap or soft clank will be emitted from the
hybrid battery (traction battery), behind the rear seats, when the hybrid sys-
tem is started or stopped.
●Sounds from the hybrid system may be heard when the back door is open.
●Sounds may be heard from the transmission when the gasoline engine
starts or stops, when driving at low speeds, or during idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is
depressed or as the accelerator pedal is released.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents. (P. 99)
■Vehicle proximity notification system
In the following cases, the vehicle proximity notification system may be diffi-
cult for surrounding people to hear.
●In very noisy areas
●In the wind or the rain
Also, as the vehicle proximity notification system is installed on the front of
the vehicle, it may be more difficult to hear from the rear of the vehicle com-
pared to the front.

PRIUS PRIME_OM_OM47D71U_(U)
972-1. Plug-in hybrid system
2
Plug-in hybrid system
■When “Proximity Notification System Malfunction Visit Your Dealer” is
displayed on the multi-information display
The vehicle proximity notification system may be malfunctioning. Have the
vehicle inspected by your Toyota dealer immediately.
■Maintenance, repair, recycling, and disposal
Contact your Toyota dealer regarding maintenance, repair, recycling and dis-
posal. Do not dispose of the vehicle yourself.
WARNING
■When using the hybrid battery (traction battery) charge mode
Observe the following precautions when using the hybrid battery (traction
battery) charge mode while parking.
Failure to do so may lead to death or serious health hazard, as the gasoline
engine operates when in the hybrid battery (traction battery) charge mode.
●Do not stop the vehicle near flammable materials.
●Do not use the hybrid battery (traction battery) charge mode in a closed
area where ventilation is insufficient, such as in a garage or area with
snow buildup.