warning light TOYOTA PRIUS PLUS 2017 Repair Manual

3877-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
7
When trouble arises
If a war ning light tur ns 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 dealer or repairer, or
another duly qualified and equipped professional.
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 dealer or repairer, or
another duly qualified and equipped professional.
Continuing to drive the vehicle may be dangerous.
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released, the system is operating normally.
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
dealer or repairer, or another duly qualified and
equipped professional 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 dealer or repairer, or
another duly qualified and equipped professional.

3887-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
(If equipped)
Low engine oil pressure warning lightIndicates that the engine oil pressure is too low
→ Immediately stop the vehicle in a safe place and con-
tact any authorized Toyota dealer or repairer, or
another duly qualified and equipped professional.
(If equipped)
Hybrid system warning light (warning buzzer)
Indicates a malfunction in the hybrid system
→ Immediately stop the vehicle in a safe place and con-
tact any authorized Toyota dealer or repairer, or
another duly qualified and equipped professional.
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
dealer or repairer, or another duly qualified and
equipped professional 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
dealer or repairer, or another duly qualified and
equipped professional immediately.
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
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
dealer or repairer, or another duly qualified and
equipped professional immediately.
Warning lightWarning light/Details/Actions

3897-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
7
When trouble arises
(Flashes)
(If equipped)
PCS warning light
Indicates a malfunction in the pre-crash safety system
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will come on when the pre-crash safety system is turned off. ( →P. 263)
• The light will flash when the system cannot temporarily be used.
Slip indicator light
Indicates a malfunction in:
• The VSC system;
• The TRC system; or
• The hill-start assist control system
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
The light will flash when the above systems and/or ABS
are operating.
(If equipped)
Parking lock system warning light (warning buzzer) Indicates a malfunction in the shift control system
• In this situation, there is a possibility that the parkinglock mechanism will not work. When parking, park the
vehicle on a flat surface and apply the parking brake
securely.
• The power switch may not be turned off. If this happens, applying the parking brake will enable the switch to be
turned off.
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
Warning lightWarning light/Details/Actions

3907-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
(If equipped)
Parking lock system warning message (warning buzzer)Indicates a malfunction in the shift control system when
the vehicle is stopped
• In this situation, there is a possibility that the parkinglock mechanism will not work. When parking, park the
vehicle on a flat surface and apply the parking brake
securely.
• The power switch may not be turned off. If this happens,
applying the parking brake will enable the switch to be
turned off.
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
(If equipped)
Hybrid battery indicator light The hybrid battery (traction battery) will soon need to be
inspected or replaced
Have the hybrid battery (traction battery) inspected by any
authorized Toyota dealer or re pairer, or another duly quali-
fied and equipped professional immediately.
*2
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
(If equipped)
LED headlight warning light Indicates a malfunction in the LED headlights
The LED headlights will not normally illuminate when
there is a malfunction, however they may be able to illu-
minate depending on the nature of the problem.
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
(Flashes)
(If equipped)
P position request indicator light (warning buzzer)
The amount of charge remaining in the hybrid battery
(traction battery) has fallen because the shift position has
been left in N for a long time
→ Because recharging is not possible when the shift
position is in N, shift the shift position to P when
parking the vehicle for a long time.
• The driver’s door has been opened while the shift posi- tion is in N, D or B
• An attempt has been made to start the hybrid system
while the shift position is in anything other than P
→ Shift the shift position to P.
Warning lightWarning light/Details/Actions

3917-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
7
When trouble arises
(If equipped)
Hybrid system overheat warning light (warning buzzer)The hybrid system has overheated
This light may come on when driving under severe operat-
ing conditions, and the output of the hybrid system may
temporarily decrease in order to protect the system. (For
example, when driving up a long steep hill or driving up a
steep hill in reverse.)
→ Stop and check. ( →P. 457)
(If equipped)
Cruise control indicator (yellow indicator)
Indicates a malfunction in the cruise control
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
(Only outer frame flashes)
(If equipped)
Low hybrid battery (traction battery) warning light
(warning buzzer)
Hybrid battery (traction battery) level becomes low
because the shift position is in N for long time
→ Because recharging is not possible when the shift
position is in N, shift the shift position to P when
parking the vehicle for a long time.
High coolant temperature warning light
Changes from a flashing to a solid light when the engine
coolant temperature increases
→ Immediately stop the vehicle in a safe place.
(→ P. 457)
Automatic headlight leveling system warning light
Indicates a malfunction in the automatic headlight leveling
system
→ Have the vehicle inspected by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional immediately.
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 6.0 L (1.6
gal., 1.3 Imp.gal.) or less
→ Refuel the vehicle.
Warning lightWarning light/Details/Actions

3927-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
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.
Rear passengers’ seat belt reminder lights (warning
buzzer)
*4
Warns the rear passengers to fasten their seat belts
→ Fasten the seat belt.
(If equipped)
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. 400
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( →P. 394)
• Flat tire ( →P. 417, 431)
→ 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 pres-
sure is adjusted, have the system checked by any
authorized Toyota dealer or repairer, or another duly
qualified and equipped professional.
When the light comes on after blinking for 1 minute:
Malfunction in the tire pressure warning system ( →P. 395)
→ Have the system checked by any authorized Toyota
dealer or repairer, or another duly qualified and
equipped professional.
Warning lightWarning light/Details/Actions

3937-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
7
When trouble arises
*1: Brake system warning buzzer:When there is a possible problem that could affect braking performance,
the warning light will come on and a warning buzzer will sound.
Parking brake engaged warning buzzer:
A buzzer will sound if the vehicle is driven at a speed of approximately
5 km/h (3 mph) or more.
*2: If you continue to use the vehicle in this state, the light starts blinking withbuzzer sounds, and you will soon become unable to start the hybrid sys-
tem.
*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 5 km/h
[3 mph]).
*4: Seat belt buzzer:The seat belt buzzer sounds to alert the driver, front passenger and rear
passengers that his or her seat belt is not fastened. The buzzer sounds for
30 seconds after the vehicle reaches a speed of 20 km/h (12 mph). Then, if
the seat belt is still unfastened, the buzzer will sound in a different tone for
90 more seconds.
Carrying out the corresponding action turns the warning light off.
Other warning light
Warning lightWarning light/Details/Actions
(If equipped)
Go to service warning light Indicates that maintenance of the hybrid battery (traction
battery) cooling component is required
The filter may be clogged, the air intake vent may be
blocked or there may be a gap in the duct.
→ Have maintenance performed on the hybrid battery
(traction battery) cooling component at any autho-
rized Toyota dealer or repairer, or another duly quali-
fied and equipped professional.

3947-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage 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
The malfunction indicator lamp will come on if the fuel tank becomes com-
pletely empty. If the fuel tank is empt y, refuel the vehicle immediately. The
malfunction indicator lamp will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized
Toyota dealer or repairer, or another duly qualified and equipped professional
as soon as possible.
■ 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. 417, 431
If the tire is not punctured:
Carry out the following procedure after the tire temperature has lowered suffi-
ciently.
● Check the tire inflation pressure and adjust to the appropriate level.
● If the warning light does not go out even after several minutes, check that
the tire inflation pressure is at the specified level and carry out initialization.
(→ P. 343)
The warning light may come on again if the above operations are conducted
without first allowing the tire temperature to lower sufficiently.
■ The tire pressure warning light may come on due to natural causes
The tire pressure warning light may turn on due to natural causes such as
natural air leaks or tire inflation pressure changes caused by temperature. In
this case, adjusting the tire inflation pressure will turn off the warning light
(after a few minutes).
■ When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and
transmitter. If a tire goes 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 adjus t the tire inflation pressure. The tire
pressure warning light will go off after a few minutes.

3957-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
7
When trouble arises
■Conditions that the tire pressure warning system may not function prop-
erly
→ P. 345
■ If the tire pressure warning light frequently comes on after blinking for
1minute
If the tire pressure warning light frequently comes on after blinking for
1 minute when the power switch is turned to ON mode, have it checked by
any authorized Toyota dealer or re pairer, or another duly qualified and
equipped professional.
■ Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location
or audio sound.

3967-2. Steps to take in an emergency
PRIUS +_OM_OM47B24E_(EE)
WARNING
■ If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized
Toyota dealer or repairer, or another duly qualified and equipped profes-
sional. The vehicle will become extremely unstable during braking, and the
ABS system may fail, which could cause an accident resulting in death or
serious injury.
■ When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
When steering wheel operations are heav ier than usually, grip the steering
wheel firmly and operate it using more force than usual.
■ 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 infla-
tion pressure immediately.
● Vehicles with spare tire: If the tire pressure warning light comes on even
after tire inflation pressure adjustment, it is probable that you have a flat
tire. Check the tires. If a tire is fl at, change it with the spare tire and have
the flat tire repaired by the nearest any authorized Toyota dealer or
repairer, or another duly qualified and equipped professional.
● Vehicles with emergency tire puncture re pair kit: If the tire pressure warn-
ing light comes on even after tire inflation pressure adjustment, it is proba-
ble that you have a flat tire. Check the tires. If a tire is flat, repair the flat tire
by using emergency tire puncture repair kit.
● Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, 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.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pres-
sure warning system may not operate properly.