2021 TOYOTA PRIUS PLUG-IN HYBRID warning light

6557-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
7
Maintenance and care
■The initialization operation
●Make sure to carry out initialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire
inflation pressure adjustment.
●If you have accidentally turned the power switch off during initialization, it is
not necessary to press the reset switch again as initialization will restart
automatically when the power switch has been turned to ON mode for the
next time.
●If you accidentally press the reset switch when initialization is not necessary,
adjust the tire inflation pressure to the specified level when the tires are
cold, and conduct initialization again.
■Warning performance of the tire pressure warning system
The warning of the tire pressure warning system will change in accordance
with the conditions under which it was initialized. For this reason, the system
may give a warning even if the tire pressure does not reach a low enough
level, or if the pressure is higher than the pressure that was adjusted to when
the system was initialized.
■When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following
cases, the settings have not been recorded and the system will not operate
properly. If repeated attempts to record tire inflation pressure settings are
unsuccessful, have the vehicle inspected by any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.
●When operating the initialization of the system, the tire pressure warning
light does not flash 3 times and the setting message does not appear on the
multi-information display.
●After driving for a certain period of time since the initialization has been
completed, the warning light comes on after blinking for 1 minute.
■Registering ID codes
The ID codes of the tire pressure warning valve and transmitters for two sets
of wheels can be registered.
It is not necessary to register the ID codes when replacing normal tires with
snow tires, if the ID codes for the wheels of both normal tires and snow tires
are registered beforehand.
For information about changing ID codes, ask any authorized Toyota retailer
or Toyota authorized repairer, or any reliable repairer.

6637-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
7
Maintenance and care
WARNING
■ When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as
dangerous handling characteristics, which may lead to an accident resulting
in death or serious injury.
● Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
● Do not use tire sizes other than those recommended by Toyota.
● Do not mix differently constructed tires (radial, bias-belted or bias-ply
tires).
● Do not mix summer, all season and snow tires.
● Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
■ When initializing the tire pressure warning system
Do not initialize the tire pressure wa rning system without first adjusting the
tire inflation pressure to the specified level. Otherwise, the tire pressure
warning light may not come on even if the tire inflation pressure is low, or it
may come on when the tire inflation pressure is actually normal.

6947-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
■After a fuse is replaced
● If the lights do not turn on even after the fuse has been replaced, a bulb may
need replacement. ( P. 695)
● If the replaced fuse blows again, have the vehicle inspected by any autho-
rized Toyota retailer or Toyota authorized repairer, or any reliable repairer.
■ If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■ When replacing light bulbs
Toyota recommends that you use genuine Toyota products designed for this
vehicle. Because certain bulbs are connected to circuits designed to prevent
overload, non-genuine parts or parts not designed for this vehicle may be
unusable.
WARNING
■ To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to the vehicle, and possibly a fire or
injury.
● Never use a fuse of a higher amperage rating than that indicated, or use
any other object in place of a fuse.
● Always use a genuine Toyota fuse or equivalent.
Never replace a fuse with a wire, even as a temporary fix.
● Do not modify the fuses or fuse boxes.
NOTICE
■Before replacing fuses
Have the cause of electrical overload determined and repaired by any
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer as soon as possible.

7017-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
7
Maintenance and care
WARNING
■ Replacing light bulbs
● Be sure to stop the hybrid system and turn off the lights. Do not attempt to
replace the bulb immediately after turning off the lights.
The bulbs become very hot and may cause burns.
● Do not touch the glass portion of the light bulb with bare hands. When it is
unavoidable to hold the glass portion, use and hold with a clean dry cloth
to avoid getting moisture and oils on the bulb.
Also, if the bulb is scratched or dropped, it may blow out or crack.
● Fully install light bulbs and any parts used to secure them. Failure to do so
may result in heat damage, fire, or water entering the light unit. This may
damage the back-up lights or cause condensation to build up on the lens.
● Do not attempt to repair or disassemble light bulbs, connectors, electric
circuits or component parts.
Doing so may result in death or serious injury due to electric shock.
● Do not replace the right-hand back-up light immediately after the vehicle
has been driven.
After the vehicle has been driven the exhaust pipe will be extremely hot,
and touching the exhaust pipe may result in burns.
● Use gloves and other protection to prevent injuries on vehicle parts.
There is the danger of being injured on the edges of parts.
■ To prevent damage or fire
● Make sure bulbs are fully seated and locked.
● Check the wattage of the bulb before installing to prevent heat damage.

703
8When trouble arises
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
8-1. Essential information
Emergency flashers ........... 704
If your vehicle has to
be stopped in an
emergency ....................... 705
If the vehicle is trapped in
rising water ...................... 706
8-2. Steps to take in an
emergency
If your vehicle needs
to be towed ...................... 707
If you think something is
wrong ............................... 713
If a warning light turns on
or a warning buzzer
sounds ............................. 714
If a warning message is
displayed ......................... 723
If you have a flat tire .......... 731
If the hybrid system will
not start............................ 749
If the electronic key does
not operate properly ........ 751
If the 12-volt battery is
discharged ....................... 755
If your vehicle
overheats ......................... 761
If the vehicle becomes
stuck ................................ 766

7138-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
8
When trouble arises
If you think something is wrong
● Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High coolant temperature warning 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, stumbling or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, spongy feeling, pedal almost touches
the floor
If you notice any of the following symptoms, your vehicle proba-
bly needs adjustment or repair. Contact any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repairer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

7148-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
If a warning light turns on or a warning
buzzer sounds
Calmly perform the following actions if any of the warning lights
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 any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
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 any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer. Continuing to
drive the vehicle 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 any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer 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 any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer.

7158-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
8
When trouble arises
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 any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer.
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 any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
ABS warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer 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 any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
Warning lightWarning light/Details/Actions