warning light TOYOTA PRIUS V 2018 Repair Manual

4828-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors (front), side impact sensors (front door), side
impact sensors (rear), driver’s seat position sensor, driver’s seat belt buckle
switch, front passenger occupant classification system (ECU and sensors),
“PASSENGER AIR BAG” indicator, front passenger’s seat belt buckle switch,
seat belt pretensioner assemblies, airbags, interconnecting wiring and power
sources. ( P. 4 1 )
■ Front passenger detection sensor, seat belt reminder and warning
buzzer
●If luggage is placed on the front passenger seat, the front passenger detec-
tion sensor may cause the warning light to flash and the warning 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 warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient of 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
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 driving trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.

4838-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
8
When trouble arises
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Push-
ing the tire pressure warning reset switch will not turn off the tire pressure
warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such
as natural air leaks and tire inflation pressure changes caused by tem-
perature. 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 adjust the tire inflation
pressure. The tire pressure warning light will go off after a few minutes.
■If the tire pressure warning system is not functioning
P. 436
■If the tire pressure warning light frequently comes on after blinking
for 1 minute
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 your Toyota dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location
or audio sound.

4848-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact your Toyota
dealer. The vehicle will become extrem ely unstable during braking, and the
ABS system may fail, which could cause an accident resulting in death or
serious injury.
■ When the electric power steerin g system warning light comes on
The steering wheel may become extremely heavy.
When steering wheel operations are heavier than usual, 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
inflation pressure immediately.
●If the tire pressure warning light comes on even after tire inflation pres-
sure 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 dealer.
●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.

4858-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
8
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 pressure
label (tire and load information label). (If your vehicle has tires of a dif-
ferent size than the size indicated on the vehicle placard or tire inflation
pressure label [tire and load information label], you should determine
the proper tire inflation pressure 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. Accordingly,
when the low tire pressure telltale (tire pressure warning light) 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 life, 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 responsibility 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 indicator to indicate when the system is not
operating properly. The TPMS (tire pressure warning system) malfunc-
tion indicator is combined with the low tire pressure telltale (tire pressure
warning light). When the system detects a malfunction, the telltale will
flash for approximately one minute and then remain continuously illumi-
nated. This sequence will continue upon subsequent vehicle start-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 tire 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 warning
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.

487
PRIUS v_OM_OM47B78U_(U)
8
When trouble arises
8-2. Steps to take in an emergency
If a warning message is displayed
Master warning light
The master warning light also
comes on or flashes in order to
indicate that a message is cur-
rently being displayed on the
multi-information display.
Multi-information display
If any of the warning lights come on again after the following actions
have been performed, contact your Toyota dealer.
If a warning is shown on the multi-information display, stay calm
and perform the following actions:
1
2

4938-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
8
When trouble arises
Warning messageDetails/Actions
The Automatic High Beam switch was pressed
with the low beam headlights turned on.
Turn the high beam headlights on before
pressing the Automatic High Beam switch.
Indicates that, since the VSC (Vehicle Stability
Control) system was turned off, the pre-collision
brake system operation is stopped
Turn the VSC on. ( P. 255)
Indicates that the PCS (Pre-Collision System) is
temporarily unavailable
When conditions improve, the system
resumes operation. If this item is displayed
continuously, have the vehicle inspected
by your Toyota dealer.
Indicates that the PCS (Pre-Collision System) is
temporarily unavailable
 When conditions improve, the system
resumes operation. If this item is displayed
continuously, have the vehicle inspected
by your Toyota dealer.
Indicates that part of the PCS (Pre-Collision Sys-
tem) sensor is dirty, covered with ice, etc.
 Remove any dirt, ice, etc.
Hybrid battery (traction battery) inspection or
replacement time.
Have the hybrid battery (traction battery)
inspected by your Toyota dealer immedi-
ately.

4978-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
8
When trouble arises
Shift control system malfunction A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer immediately. If not inspected, vehi-
cle systems may stop operating normally.
Shift control system communication malfunction
A buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
• The hybrid system may not be able to start.
• May not be switched to the P position. When parking, choose a level location and
apply the parking brake securely.
• The automatically P position selection func- tion ( P. 178) may not function. Before
turning the power switch off, securely press
the P position switch, and be sure to check
that the shift position is in P by verifying the
shift position or P position switch operation
indicator lights.
• The power switch may not be able to be
turned off. In this case, the power switch
may be turned off by applying the parking
brake.
(If equipped)
Indicates a malfunction in the LED headlight sys-
temA buzzer also sounds.
 Have the vehicle inspected by your Toyota
dealer.
Warning messageDetails/Actions
(Turns on or
Flashes)

5168-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE
ONLY” on the tire sidewall.
Use the compact spare tire temporarily, and only in an emergency.
●Make sure to check the tire inflation pressure of the compact spare tire.
( P. 543)
■After completing the tire change
The tire pressure warning system must be reset. ( P. 432)
■When using the compact spare tire
As the compact spare tire is not equipped with a tire pressure warning
valve and transmitter, low inflation pressure of the spare tire will not be
indicated by the tire pressure warning system. Also, if you replace the
compact spare tire after the tire pressure warning light comes on, the light
remains on.
■When the compact spare tire is equipped
The vehicle becomes lower when driving with the compact spare tire
compared to when driving with standard tires.
■If you have a flat front tire on a road covered with snow or ice
Install the compact spare tire on one of the rear wheels of the vehicle.
Perform the following steps and fit tire chains to the front tires:
Replace a rear tire with the compact spare tire.
Replace the flat front tire with the tire removed from the rear of the vehi-
cle.
Fit tire chains to the front tires.
1
2
3

5268-2. Steps to take in an emergency
PRIUS v_OM_OM47B78U_(U)
WARNING
■Avoiding 12-volt battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flam-
mable gas that may be emitted from the 12-volt battery:
●Make sure each jumper cable is connected to the correct terminal and that
it is not unintentionally in contact with any other than the intended terminal.
● Do not allow the other end of the jumper cable connected to the “+” termi-
nal to come into contact with any other parts or metal surfaces in the area,
such as brackets or unpainted metal.
● Do not allow the + and - clamps of the jumper cables to come into contact
with each other.
● Do not smoke, use matches, cigarette lighters or allow open flame near
the 12-volt battery.
■ 12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte,
while related parts contain lead and lead compounds. Observe the following
precautions when handling the 12-volt battery:
●When working with the 12-volt battery, always wear safety glasses and
take care not to allow any battery fluids (acid) to come into contact with
skin, clothing or the vehicle body.
● Do not lean over the 12-volt battery.
● In the event that battery fluid comes into contact with the skin or eyes,
immediately wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention
can be received.
● Always wash your hands after handling the 12-volt battery support, termi-
nals, and other battery-related parts.
● Do not allow children near the 12-volt battery.
■ After recharging the 12-volt battery
Have the 12-volt battery inspected at your Toyota dealer as soon as possi-
ble.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt
battery to emit a malodorous gas, which may be detrimental to the health of
passengers.
■ When replacing the 12-volt battery
P. 429

528
PRIUS v_OM_OM47B78U_(U)
8-2. Steps to take in an emergency
If your vehicle overheats
■If the high coolant temperature warning light comes on or
flashesStop the vehicle in a safe place and turn off the air conditioning
system, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect the
hoses and radiator core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The following may indicate that your vehicle is overheating.● The high coolant temperature warning light ( P. 480) comes on
or flashes, or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
● The warning message indicating overheat is shown on the multi-
information display. ( P. 492)
● Steam comes out from under the hood.
Correction procedures
1
2
3
1
2