Acc TOYOTA PRIUS PRIME 2023 Owner's Guide

792-1. Plug-in hybrid system
2
Plug-in hybrid system
■Gasoline engine operation in
EV mode or AUTO EV/HV mode
Even if there is a sufficient amount
of electricity remain ing in the hybrid
battery (traction battery) and EV
driving range ( P.155) is being dis-
played on the meter, EV driving
(driving using only the electric
motor) may be canceled and both
gasoline engine and electric motor
are used depending on the situation
(EV driving will be returned to auto-
matically after EV driving becomes
possible again).
EV driving may be canceled auto-
matically in the following circum-
stances
*1:
●When vehicle speed is more than
approximately 84 mph (135 km/h).
●When power is needed temporar-
ily, for example when the acceler-
ator pedal is depressed firmly or
when accelerating suddenly.
*2
●When the temperature of the
hybrid system is high.
The vehicle has been left in the
sun, driven on a h ill, driven at high
speeds, etc.
●When the temperature of the
hybrid system is low.
●When the heater is switched on
when the outside temperature is
below about 14°F (-10°C).
●When the windshield defogger
switch is pressed. ( P.434)
●When the system determines that
the gasoline engine needs to be
started.
*1: The gasoline engine may also
operate in circumstances other
than those listed above, depend-
ing on conditions.
*2: When driving in AUTO EV/HV mode. Even in EV mode, the gas-
oline engine may start, depend-
ing on the condition of the hybrid
battery (traction battery).
■If “Engine Started to Protect
System EV driving unavailable”
is displayed on the multi-infor-
mation display
EV driving may be canceled in order
to protect the hybrid system, etc.
In this case, perform driving with the
gasoline engine until EV driving will
be returned to automatically.
Depending on the conditions, driv-
ing that combines the use of the
gasoline engine may continue for a
short while. However, this is not a
malfunction.
■Conditions in which the gaso-
line engine may not stop
The gasoline engine starts and
stops automatically . However, it
may not stop automatically in the
following conditions
*:
●During gasoline engine warm-up
●During hybrid battery (traction bat-
tery) charging
●When the temperature of the
hybrid battery (traction battery) is
high or low
●When the windshield defogger
switch is pressed. ( P.434)
*: Depending on the circumstances,
the gasoline engine may also not
stop automatically in situations
other than those above.
■Sounds and vibrations specific
to a Plug-in Hybrid Electric
Vehicle
Because there is no engine sound
or vibration, it is easy to mistake the
Plug-in Hybrid Electric Vehicle for
being off when it is actually still run-
ning, as indicated by the “READY”
indicator being illuminated. For
safety, make sure to always shift the
shift position to P and apply the
parking brake when parked.
The following sounds or vibrations
may occur when the hybrid system
is operating and are not a malfunc-
tion.

802-1. Plug-in hybrid system
●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), under the rear seats or
under the floor, when the hybrid
system 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 driv-
ing 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.
●Sounds may be heard from near
the hybrid battery (traction battery)
in accordance with the operation
of the air conditioning system or
battery cooler. ( P.109)
■Maintenance, repair, recycling,
and disposal
Contact your Toyota dealer regard-
ing maintenance, repair, recycling
and disposal. Do not dispose of the
vehicle yourself.
In order to make EV mode or
AUTO EV/HV mode available,
charge the hybrid battery (trac-
tion battery) from an external
power source before using the
vehicle.
Even if charging the hybrid battery
(traction battery) has not been com-
pleted, the vehicle can be driven.
However, if there is not enough
charge remaining, it is possible that
the vehicle cannot be driven in EV
mode or AUTO EV/HV mode or the
EV driving range will become
shorter.
■Refilling fuel
Plug-in Hybrid Electric Vehicles can
be driven using electricity charged
from an external power source.
However, as the gasoline engine is
used depending on the situation
(  P.79) even if in EV mode or
AUTO EV/HV mode, and the gaso-
line engine is provided on board as
a power source for driving in HV
mode, it is needed to refueling the
vehicle.
Check the fuel amount and refill
immediately when the fuel level
becomes low. ( P.279)
■If the vehicle is not used for a
long time
●The 12-volt battery may dis-
charge. In this event, charge the
12-volt battery. ( P.589)
In order to prevent the hybrid bat-
tery (traction batt ery) from becom-
ing extremely low in charge,
Charging ( P.94)

812-1. Plug-in hybrid system
2
Plug-in hybrid system
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 12-volt battery is dis-
charged, refer to P.589, “If the 12-
volt battery is discharged” and
perform the correction procedure.
●When the vehicle is left with the
AC charging cable connected, the
electricity consumption amount of
the 12-volt battery increases due
to controls, such as the system
checking, operating. When the AC
charging cable is not needed,
remove it from the vehicle.
When driving with the gasoline
engine stopped, a sound, which
changes in accordance with the
driving speed, will be played in
order to warn people nearby of
the vehicle’s approach. The
sound will stop when the vehicle
speed exceeds approximately
22 mph (35 km/h).
■Acoustic Vehicle Alerting Sys-
tem
In the following cases, the Acoustic
Vehicle Alerting System may be dif-
ficult for surrounding people to hear.
●In very noisy areas
●In the wind or the rain
Also, as the Acoustic Vehicle Alert- ing System is installed on the front
of the vehicle, it may be more diffi-
cult to hear from the rear of the vehi-
cle compared to the front.
■When “Acoustic Vehicle Alert-
ing System Malfunction Visit
your Dealer” is displayed on the
multi-information display
The Acoustic Vehicle Alerting Sys-
tem may be malfunctioning. Have
the vehicle inspected by your
Toyota dealer immediately.
*: This function can only be used in the mainland U.S.A. It cannot be
used in other states and territo-
ries, including Alaska and Hawaii.
This system operates based on
the driving situation and traffic
information to enhance fuel
economy.
For details about Predictive effi-
cient drive, refer to “MULTIME-
DIA OWNER’S MANUAL”.
■Predictive deceleration sup-
port
 When the vehicle approaches
to predictive deceleration sup-
port points registered in the
navigation system, the refer-
ence operation range ( ) of
the ECO Accelerator Guid-
ance ( P.163) on the multi-
information display will be
turned off to encourage the
driver to reduce excessive
acceleration.
Acoustic Vehicle Alerting
System
Predictive efficient drive
(vehicles with navigation
system)
*
A

822-1. Plug-in hybrid system
The engine braking force will
be increased according to the
driving conditions to more effi-
ciently charge the hybrid bat-
tery (traction battery) after the
accelerator pedal is released.

852-1. Plug-in hybrid system
2
Plug-in hybrid system
WARNING
●Never try to open the service
plug access hole located in the
luggage compartment. The ser-
vice plug is used only when the
vehicle is serviced and is sub-
ject to high voltage.
■Road accident cautions
Observe the following precautions
to reduce the risk of death or seri-
ous injury:
●Stop the vehicle in a safe place
to prevent subsequent acci-
dents. While depressing the
brake pedal, apply the parking
brake and shift the shift position
to P to stop the Plug-in hybrid
system. Then, slowly release
the brake pedal.
●Do not touch the high voltage
parts, cables and connectors.
●If electric wires are exposed
inside or outside your vehicle,
an electric shock may occur.
Never touch exposed electric
wires.
●Do not touch the battery if liquid
is leaking from or adhering to it.
If electrolyte (carbonic-based
organic electrolyte) from the
hybrid battery (traction battery)
comes into contact with the
eyes or skin, it could cause
blindness or skin wounds. In the
unlikely event that it comes into
contact with the eyes or skin,
wash it off immediately with a
large amount of water, and seek
immediate medical attention.
●If electrolyte is leaking from the
hybrid battery (traction battery),
do not approach the vehicle.
Even in the unlikely event that
the hybrid battery (traction bat-
tery) is damaged, the internal
construction of the battery will
prevent a large amount of elec-
trolyte from leaking out. How-
ever, any electrolyte that does
leak out will give off a vapor.
This vapor is an irritant to skin
and eyes and could cause acute
poisoning if inhaled.
●Do not bring burning or high-
temperature items close to the
electrolyte. The electrolyte may
ignite and cause a fire.
●If a fire occurs in the Plug-in
Hybrid Electric Vehicle, leave
the vehicle as soon as possible.
Never use a fire extinguisher
that is not meant for electric
fires. Using even a small
amount of water may be dan-
gerous.
●If your vehicle needs to be
towed, do so with front wheels
raised. If the wheels connected
to the electric motor (traction
motor) are on the ground when
towing, the motor may continue
to generate electricity. This may
cause a fire. ( P.550)
●Carefully inspect the ground
under the vehicle. If you find
that liquid has leaked onto the
ground, the fuel system may
have been damaged. Leave the
vehicle as soon as possible.
■Hybrid battery (traction bat-
tery)
●Your vehicle contains a sealed
lithium-ion battery.

862-1. Plug-in hybrid system
WARNING
●Never resell, hand over or mod-
ify the hybrid battery. To prevent
accidents, hybrid batteries that
have been removed from a dis-
posed vehicle are collected
through Toyota dealer. Do not
dispose of the battery yourself.
Unless the battery is properly
collected, the following may
occur, resulting in death or seri-
ous injury:
• The hybrid battery may be ille- gally disposed of or dumped,
and it is hazardous to the envi-
ronment or someone may touch
a high voltage part, resulting in
an electric shock.
• The hybrid battery is intended to be used exclusively with your
Hybrid Electric Vehicle. If the
hybrid battery is used outside of
your vehicle or modified in any
way, accidents such as electric
shock, heat generation, smoke
generation, an explosion and
electrolyte leakage may occur.
When reselling or handing over
your vehicle, the possibility of
an accident is extremely high
because the person receiving
the vehicle may not be aware of
these dangers.
●If your vehicle is disposed of
without the hybrid battery hav-
ing been removed, there is a
danger of serious electric shock
if high voltage parts, cables and
their connectors are touched. In
the event that your vehicle must
be disposed of, the hybrid bat-
tery must be disposed of by
your Toyota dealer or a qualified
service shop. If the hybrid bat-
tery is not disposed of properly,
it may cause electric shock that
can result in death or serious
injury.
■Caution while driving
If the vehicle under floor area
receives strong shock or impact
while driving, stop the vehicle in a
safe area and check around the
bottom of the vehicle. If there is
damage to the hybrid battery
(traction battery) or liquid leakage,
it may lead to a vehicle fire, etc.
Do not touch the vehicle and
immediately contact your Toyota
dealer.
Even if no damage can be seen
under the floor, the hybrid battery
(traction battery) may be dam-
aged. If the vehicle under floor
area receives strong shock or
impact, have the hybrid battery
(traction battery) inspected by
your Toyota dealer.
■Modifications
Do not modify the vehicle to make
the height lower.
It is easier for the hybrid battery
(traction battery) in the under floor
area to come in contact with the
ground when the vehicle is low-
ered. If the hybrid battery (traction
battery) is damaged, a vehicle fire
may occur which could lead to
death or serious injury.
NOTICE
■Notice about fuel
●For Plug-in Hybrid Electric Vehi-
cles, fuel may remain in the tank
for a long time and undergo
changes in quality depending
on the how the vehicle is used.
Refuel at least 5.3 gal. (20 L,
4.4 Imp.gal.) of fuel every 12
months (refuel a total of at least
5.3 gal. [20 L, 4.4 Imp.gal.] over
a 12-month period), as this may
affect components of the fuel
system or the gasoline engine.

882-1. Plug-in hybrid system
Primarily using EV mode and
AUTO EV/HV mode when driv-
ing in cities and using HV mode
when driving on highways (or
freeways) can help conserve
fuel and electricity. (P.74)
When using Eco drive mode, the
torque corresponding to the
accelerator pedal depression
amount can be generated more
smoothly than it is in normal
conditions. In addition, the oper-
ation of the air conditioning sys-
tem (heating/cooling) will be
minimized, improving fuel and
electricity economy. ( P.422)
Eco-friendly driving is possible
by keeping the Hybrid System
Indicator within Eco area.
( P.158) Shift the shift position to D when
stopped at a traffic light, or driv-
ing in heavy traffic etc. Shift the
shift position to P when parking.
When using the N, there is no
positive effect on fuel consump-
tion. In the N, the gasoline
engine operates but electricity
cannot be generated. Also,
when using the air conditioning
system, etc., the hybrid battery
(traction battery) power is con-
sumed.

Drive your vehicle smoothly.
Avoid abrupt acceleration and
deceleration. Gradual accel-
eration and deceleration will
make more effective use of
the electric motor (traction
motor) without having to use
gasoline engine power.
 Avoid repeated acceleration.
Repeated acceleration con-
sumes hybrid battery (trac-
tion battery) po wer, resulting
in poor fuel consumption. Bat-
tery power can be restored by
driving with the accelerator
pedal slightly released.
Make sure to operate the brakes
Plug-in Hybrid Elec-
tric Vehicle driving
tips
For economical and ecolog-
ical driving, pay attention to
the following points:
Using EV mode, AUTO
EV/HV mode and HV
mode effectively
Using Eco drive mode
Use of Hybrid System
Indicator
Changing the shift posi-
tion
Accelerator pedal/brake
pedal operation
When braking

892-1. Plug-in hybrid system
2
Plug-in hybrid system
gently and a timely manner.
A greater amount of electrical
energy can be regenerated
when slowing down.
Repeated acceleration and
deceleration, as well as long
waits at traffic lights, will lead to
high fuel and electricity con-
sumption. Check traffic reports
before leaving and avoid delays
as much as possible. When driv-
ing in a traffic jam, gently
release the brake pedal to allow
the vehicle to move forward
slightly while avoiding overuse
of the accelerator pedal. Doing
so can help control excessive
electricity and fuel consumption.
 Control and maintain the vehi-
cle at a constant speed.
Before stopping at a toll booth
or similar, allow plenty of time
to release the accelerator and
gently apply the brakes. A
greater amount of electrical
energy can be regenerated
when slowing down.
 Electricity consumption will
increase significantly when
driving at high speeds in EV
mode or AUTO EV/HV mode.
If there will be a long distance
to the next external charging
point after leaving a freeway, it is recommended to drive in
HV mode while on the free-
way and change to EV mode
or AUTO EV/HV mode after
leaving the freeway. (
P.74)
 Turn the “A/C” switch off
when it is not needed. Doing
so can help reduce excessive
electricity and fuel consump-
tion.
In summer: When the ambient tem-
perature is high, use the recircu-
lated air mode. Doin g so will help to
reduce the burden on the air condi-
tioning system and reduce electric-
ity and fuel consumption as well.
In winter: Avoid excessive and
unnecessary use of the heater.
Usage of the heated steering wheel
(if equipped) and seat heaters (if
equipped) are effective. ( P.443)
Make sure to check the tire infla-
tion pressure frequently. If there
is improper tire inflation pres-
sure in the tires, the EV driving
range will become shorter, and
fuel consumption when in HV
mode will increase.
Also, as snow tires can cause
large amounts of friction, their
use on dry roads can lead to
increased fuel and electricity
consumption.
Delays
Highway driving
Air conditioning
Checking tire inflation
pressure

912-1. Plug-in hybrid system
2
Plug-in hybrid system
automatically records the elec-
tricity consumption when being
charged and uses the electricity
consumption for estimating the
EV driving range. Therefore, the
EV driving range displayed
when the hybrid battery (traction
battery) is fully charged may dif-
fer from the previous EV driving
range depending on how the
vehicle was driven.
The EV driving range may
change significantly with each
charging until the electricity con-
sumption based on the recorded
value is stable (for approxi-
mately the first month or two).
However, this does not indicate
a malfunction.
When the air conditioning sys-
tem is turned on, the EV driving
range (with using the air condi-
tioning system) is estimated
based on the past air condition-
ing electricity consumption
amount considering that the
electricity consumption may
become higher.
The distance that EV driving is
possible varies significantly
depending on how the vehicle is
driven, road conditions, the
weather, the outside tempera-
ture, usage conditions of electri-
cal components and the number of occupants.
The distance that EV driving is
possible can be extended if the
following is performed:
■When starting off, depress
the accelerator pedal
smoothly to accelerate
As a guide, accelerate up to
approximately 12mph (20 km/h)
in the first 5 seconds.
Electrical and fuel efficiency can
be improved just by using the
ECO Accelerator Guidance dis-
played on the multi-information
display and taking care to start
off gently. ( P.163)
When the driving mode is set to
Eco drive mode, depressing the
accelerator pedal generates
smooth torque that makes it easier
to operate the accelerator gently.
At the same time, the air condition-
ing control is switched to eco air
conditioning mode ( P.437) to
reduce the strength of the air condi-
tioning operation.
■Maintain sufficient vehicle-
to-vehicle distance and do
not accelerate or decelerate
unnecessarily
Try to maintain a fixed speed
while driving. Driving at a short
vehicle-to-vehicle distance will
result in repeating wasteful
acceleration and deceleration,
which will worsen the electrical
and fuel efficiency.
Tips for extending the EV
driving range

922-1. Plug-in hybrid system
■Release the accelerator
pedal early before stopping
the vehicle, such as at a
traffic light
The regenerative brake will
operate to convert the kinetic
energy of the vehicle into electri-
cal energy, which will charge the
hybrid battery (traction battery).
The regeneration status can be
checked from the Hybrid Sys-
tem Indicator. ( P.158)
When the brake pedal is
depressed lightly during decel-
eration, the regeneration
amount increases, enabling
more electrical energy to be
recovered.
If the brake pedal is depressed too
strongly, the recovered amount
indicator will reach the maximum
level and the upper limit of the
recoverable en ergy will be
exceeded. Therefore, be sure to
operate the brake pedal early.
■Use the air conditioning
system appropriately, and
also utilize the heated steer-
ing wheel (if equipped) and
seat heaters (if equipped)
In EV mode, the vehicle is
cooled and heated by electrical
energy. (Except in extremely
cold temperatures of approxi-
mately 14°F [-10°C] or less.)
Preventing excessive cooling or
heating of the vehicle will reduce
power consumption and
improve electrical efficiency. When eco air conditioning mode
is used, the air conditioning con-
trol is switched automatically to
a lower setting. (
P.437)
The heated steering wheel and
seat heaters are efficient heat-
ing device that directly warm the
body using less electric power.
When used together with the air
conditioning system, a low tem-
perature setting can be used to
improve electrical and fuel effi-
ciency.
■Check the tire pressure
If the tire pressure is lower than
the specified value, it will
worsen the electrical and fuel
efficiency.
A pressure level 7 psi (50 kPa, 0.5
kgf/cm
2 or bar) lower than the spec-
ified value will cause a worsening of
several percentage points.
■When driving on highways,
use the EV/HV mode selec-
tion switch to drive in HV
mode
The power consumption will
increase significantly if the vehi-
cle is driven in EV mode on
highways.
■Do not load unnecessary
objects in the vehicle
Driving with objects weighing
220 lb. (100 kg) in the vehicle
will worsen the electrical and
fuel efficiency by approximately
3%.
Air resistance also greatly