2023 TOYOTA PRIUS PRIME ECU

5417-3. Do-it-yourself maintenance
7
Maintenance and care
using the pullout tool.
4Check if the fuse is blown.
Replace the blown fuse with a new
fuse of an appropriate amperage
rating. The amperage rating can be
found on the fuse box lid.
Type A
Normal fuse
Blown fuse
Type BNormal fuse
Blown fuse
Type CNormal fuse
Blown fuse
■After a fuse is replaced
●When installing the lid, make sure
that the tab is in stalled securely.
●If the lights do not turn on even
after the fuse has been replaced,
a lights may need replacement.
( P.543)
●If the replaced fuse blows again,
have the vehicle inspected by
your Toyota dealer.
■If there is an overload in a cir-
cuit
The fuses are designed to blow,
protecting the wiring harness from
damage.
■When replacing an electronic
component, such as a lights,
etc.
Toyota recommends that you use
genuine Toyota products designed
for this vehicle.
Because certain electronic compo-
nents are connected to circuits
designed to prevent overload, non-
genuine parts not designed for this
vehicle may be unusable.
A
B
A
B
A
B

5478-1. Essential information
8
When trouble arises
1Steadily step on the brake
pedal with both feet and
firmly depress it.
Do not pump the brake pedal
repeatedly as this will increase the
effort required to slow the vehicle.
2Shift the shift position to N.
If the shift position is shifted to
N
3 After slowing down, stop the
vehicle in a safe place by the
road.
4 Stop the hybrid system.
If the shift position cannot be
shifted to N
3 Keep depressing the brake
pedal with both feet to reduce
vehicle speed as much as
possible.
4 To stop the hybrid system,
press and hold the power
switch for 2 consecutive sec-
onds or more, or press it briefly 3 times or more in suc-
cession.
5 Stop the vehicle in a safe
place by the road.
■If emergency stopped
The functions of the air conditioning,
etc. may be partially limited in order
to reduce the power consumption of
the 12-volt battery.
If your vehicle has to
be stopped in an emer-
gency
Only in an emergency, such
as if it becomes impossible
to stop the vehicle in the
normal way, stop the vehi-
cle using the following pro-
cedure:
Stopping the vehicle
WARNING
■If the hybrid system has to be
turned off while driving
Turning the hybrid system off
while driving will not cause loss of
steering or braking control. How-
ever, power assist for the steering
wheel may be lost making it diffi-
cult to steer smoothly before stop-
ping the vehicle depending on the
remaining charge in the 12-volt
battery or usage conditions.
Decelerate as much as possible
before turning off the hybrid sys-
tem.

5518-2. Steps to take in an emergency
8
When trouble arises
From the rear
Use a towing dolly under the
front wheels.
When using a flat-bed truck to
transport the vehicle, use tire
strapping belts. Refer to the
owner’s manual of the flat-bed
truck for the tire strapping
method.
In order to suppress vehicle move-
ment during transp ortation, set the
parking brake and turn the power
switch off.
If a tow truck is not available in
an emergency, your vehicle may
be temporarily towed using
cables or chains secured to the
emergency towing eyelets.
WARNING
Observe the following precau-
tions. Failure to do so may result
in death or serious injury.
■When towing the vehicle
Be sure to transport the vehicle
with the front wheels raised or
with all four wheels raised off the
ground. If the vehicle is towed
with the front wheels contacting
the ground, the drivetrain and
related parts may be damaged or
electricity generated by the opera-
tion of the motor may cause a fire
to occur depending on the nature
of the damage or malfunction.
NOTICE
■To prevent damage to the
vehicle when towing using a
wheel-lift type truck
When raising the vehicle, ensure
adequate ground clearance for
towing at the opposite end of the
raised vehicle. Without adequate
clearance, the vehicle could be
damaged while being towed.
■Towing with a sling-type
truck
Do not tow with a sling-type truck
to prevent body damage.
Using a flatbed truck
Emergency towing

5528-2. Steps to take in an emergency
This should only be attempted
on hard surfaced roads for short
distances at under 18 mph (30
km/h).
A driver must be in the vehicle to
steer and operate the brakes.
The vehicle’s wheels, drive
train, axles, steering and brakes
must be in good condition.
To have your vehicle towed by
another vehicle, the towing eye-
let must be installed to your
vehicle. Install the towing eyelet
using the following procedure.
1Take out the towing eyelet.
( P.575)
2 Remove the eyelet cover
using a flathead screwdriver.
To protect the bodywork, place a
rag between the screwdriver and
the vehicle body as shown in the
illustration.
3Insert the towing eyelet into
the hole and tighten partially
by hand.
4 Tighten down the towing eye-
let securely using a wheel nut
wrench or hard metal bar.
5 Securely attach cables or
chains to the towing eyelet.
Take care not to damage the vehi-
cle body.
6Enter the vehicle being towed
and start the hybrid system.
Turn off the Parking Support Brake
function. (if equipped): ( P.384)
If the hybrid system does not start,
turn the power switch to ON.
7 Shift the shift position to N
and release the parking
brake.
Turn automatic mode off. ( P.264)
Emergency towing proce-
dure

5538-2. Steps to take in an emergency
8
When trouble arises
■While towing
If the hybrid system is off, the power
assist for the brakes and steering
will not function, making steering
and braking more difficult.
■Wheel nut wrench
Wheel nut wrench can be pur-
chased at your Toyota dealer.
WARNING
Observe the following precau-
tions. Failure to do so may result
in death or serious injury.
■While towing
●When towing using cables or
chains, avoid sudden starts, etc.
which place excessive stress on
the towing eyelets, cables or
chains. The towing eyelets,
cables or chains may become
damaged, broken debris may hit
people, and cause serious dam-
age.
●Do not perform any of the fol-
lowing as doing so may cause
the parking lock mechanism to
engage, locking the front
wheels and possibly leading to
an accident resulting in death or
serious injury:
• Unfasten the driver’s seat belt and open the driver’s door.
• Turn the power switch off.
■Installing towing eyelets to
the vehicle
Make sure that towing eyelets are
installed securely. If not securely
installed, towing eyelets may
come loose during towing.
NOTICE
■To prevent damage to the
vehicle during emergency
towing
Do not secure cables or chains to
the suspension components.

5638-2. Steps to take in an emergency
8
When trouble arises
passenger that his or her seat belt is not fastened. If the seat belt is
unfastened, the buzzer sounds intermitte ntly for a certain period of time,
after the seat belt is fastened and unfastened and the vehicle reaches a
certain speed.
■Warning buzzer
In some cases, the buzzer may not
be heard because of noisy place or
an audio sound.
■Front passenger detection sen-
sor, seat belt reminder and
warning buzzer
●If luggage is placed on the front
passenger seat, the front passen-
ger detection 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 pas-
senger, and the warning light may
not operate properly.
■If the malfunction indicator
lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fu el tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several
driving trips.
If the light does not go off even after
several trips, contact your Toyota
dealer as soon as possible.
■Electric power steering system
warning light (warning buzzer)
When the 12-volt battery charge
becomes insufficient or the voltage
temporarily drops, the electric power
steering system warning light may
come on and the warning buzzer
may sound.
At this time, the functions of the air
conditioning, etc. may be partially
limited in order to reduce the power consumption of the 12-volt battery.
■When the tire pressure warning
light comes on
Inspect the tires to check if a tire is
punctured.
If a tire is punctured: P.574
If none of the tires are punctured:
Turn the power switch off then turn it
to ON.
Check if the tire pressure warning
light comes on or blinks.
If the tire pressure warning light
blinks for approximately 1 minute
then stays on
There may be a malfunction in the
tire pressure wa rning system. Have
the vehicle inspected by your
Toyota dealer immediately.
If the tire pressure warning light
comes on
After the temperature of the tires
has lowered sufficiently, check the
inflation pressure of each tire and
adjust them to th e specified level.
If the warning light does not turn off
even after several minutes have
elapsed, check that the inflation
pressure of each tire is at the speci-
fied level and perform the tire infla-
tion pressure setting procedure.
(  P.524)
If the warning light does not turn off
even after several minutes have
elapsed since performing the tire
inflation pressure setting proce-
dure, have the vehicle inspected by
your Toyota dealer as soon as pos-
sible.

5688-2. Steps to take in an emergency
To prevent the shift lever from being
operated incorrectly or the vehicle
from moving unexpectedly, a mes-
sage that requires shifting the shift
position may be displayed on the
multi-information display.
In that case, follow the instruction of
the message and shift the shift posi-
tion.
●If a message or image about an
open/close state of a part or
replenishment of a consumable is
shown
Confirm the part indicated by the
multi-information di splay or a warn-
ing light, and then perform the cop-
ing method such as closing the
open door or replenishing a con-
sumable.
■If a message that indicates the
need for visiting your Toyota
dealer is displayed
The system or part shown on the
multi-information di splay is malfunc-
tioning. Have the vehicle inspected
by your Toyota dealer immediately.
■If a message that indicates the
need for referring to Owner’s
Manual is displayed
●If “Engine Coolant Temp High” is
shown, follow the instructions,
accordingly. ( P.594)
●If the following messages are
shown, there may be a malfunc-
tion. Immediately have the vehi-
cle inspected by your Toyota
dealer.
• “Plug-in Charging System Mal-
function”
• “Hybrid System Malfunction”
• “Check Engine”
• “Traction battery system malfunc- tion”
• “Accelerator System Malfunction”
• “Smart Key System malfunction”
• “Shift System Malfunction Apply Parking Brake Se curely When
Parking See Owner’s Manual” • “P Switch Malfunction Apply Park-
ing Brake Securely When Parking
See Owner’s Manual”
• “Shift System Unavailable Apply Parking Brake Securely When
Parking See Owner’s Manual”
• “Shift System Malfunction See Owner’s Manual”
• “Shift System Malfunction Stop in
a Safe Place See Owner’s Man-
ual”
• “Battery Low Shifting Unavailable
See Owner’s Manual”
●If the following messages are
shown, there may be a malfunc-
tion. Immediately stop the vehicle
in a safe place and contact your
Toyota dealer. Continuing to drive
the vehicle may be dangerous.
• “Oil pressure low”
• “Braking Power Low”
●If any of the following messages
are shown on the multi-informa-
tion display, the vehicle may have
run out of fuel. Stop the vehicle in
a safe place and, if the fuel level is
low, refuel the vehicle.
• “Hybrid system stopped”
• “Engine stopped No Fuel”
●If “12-Volt Battery Charging Sys-
tem Malfunction Stop in a Safe
Place See Owner’s Manual” is
shown
Indicates a malfunction in the vehi-
cle’s charging system. Pull over and
stop the vehicle as soon as it is safe
to do so.
While the message is displayed, the
functions of the air conditioning, etc.
may be partially lim ited in order to
reduce the power consumption of
the 12-volt battery.
■If “Traction battery needs to be
protected. Refrain from the use
of N position.” is shown
This message may be displayed
when the shift position is in N.
As the hybrid battery (traction bat-
tery) can not be charged when the

5778-2. Steps to take in an emergency
8
When trouble arises
duced. This does not indicate a
malfunction.
●Do not use to check or to adjust
the tire pressure.
1Open the deck board.
( P.454).
2 Take out the emergency tire
puncture repair kit.
1 Take out the repair kit from
the plastic bag.
Attach the sticker enclosed with the
bottle on the specified locations.
(See step 10.)
2Pull out the hose and power
plug from the bottom side of
the compressor.
3 Connect the bottle to the
compressor.
Make sure to press the bottle until
its claws are securely engaged to
the compressor and no longer visi-
WARNING
■Do not drive the vehicle with
a flat tire
Do not continue driving with a flat
tire. Driving even a short distance
with a flat tire can damage the tire
and the wheel beyond repair.
Driving with a flat tire may cause a
circumferential groove on the side
wall. In such a case, the tire may
explode when using a repair kit.
■Caution while driving
●Store the repair kit in the lug-
gage compartment.
Injuries may result in the event
of an accident or sudden brak-
ing.
●The repair kit is exclusively only
for your vehicle.
Do not use repair kit on other
vehicles, which could lead to an
accident causing death or seri-
ous injury.
●Do not use repair kit for tires
that are different size than the
original ones, or for any other
purpose. If the tires have not
been completely repaired, it
could lead to an accident caus-
ing death or serious injury.
■Precautions for use of the
sealant
●Ingesting the sealant is hazard-
ous to your health. If you ingest
sealant, consume as much
water as possible, and then
immediately consult a doctor.
●If sealant gets in eyes or
adheres to skin, immediately
wash it off with water. If discom-
fort persists, consult a doctor.
Taking out the emergency
tire puncture repair kit
Emergency repair method