2023 TOYOTA PRIUS PRIME Owners Manual

4255-5. Using the driving support systems
5
Driving
wheel.
■The Secondary Collision
Brake
When the SRS airbag sensor
detects a collision and the sys-
tem operates, the brakes and
brake lights are automatically
controlled to reduce the vehicle
speed and help reduce the pos-
sibility of further damage due to
a secondary collision.
■When the TRAC/VSC/ABS sys-
tems are operating
The slip indicator light will flash
while the TRAC/VSC/ABS systems
are operating.
■Disabling the TRAC system
If the vehicle gets stuck in mud, dirt
or snow, the TRAC system may
reduce power from the hybrid sys-
tem to the wheels.
Pressing to turn the system off
may make it easier for you to rock
the vehicle in order to free it.
To turn the TRAC system off,
quickly press and release . The “Traction Control Turned OFF”
will be shown on the multi-informa-
tion display.
Press again to turn the system
back on.
■Turning off both TRAC and VSC
systems
To turn the TRAC and VSC systems
off, press and hold for more than
3 seconds while the vehicle is
stopped.
The VSC OFF indicator light will
come on and the “Traction Control
Turned OFF” will be shown on the
multi-informat ion display.
*
Press again to turn the systems
back on.
*: PCS (Pre-Collision System) will
also be disabled (only pre-collision
warning is available). The PCS
warning light will come on and a
message will be disp layed on the
multi-information display.
(  P.298)
■When the message is dis-
played on the mu lti-information
display showing that TRAC has
been disabled even if has
not been pressed
TRAC is temporary deactivated. If
the information continues to show,
contact your Toyota dealer.
■Operating conditions of hill-
start assist control
When all of the following conditions
are met, the hill-start assist control
will operate:
●The shift position is in a position
other than P or N (when starting
off forward/backward on an
upward incline)
●The vehicle is stopped

4265-5. Using the driving support systems
●The accelerator pedal is not
depressed
●The parking brake is not engaged
●The power switch is in ON
■Automatic system cancelation
of hill-start assist control
The hill-start assist control will turn
off in any of the following situations:
●Shift the shift position to P or N.
●The accelerator pedal is
depressed
●The brake pedal is depressed and
the parking brake is engaged
●A maximum of 2 seconds have
elapsed after the brake pedal is
released
●The power switch is turned to OFF
■Sounds and vibrations caused
by the ABS, brake assist, VSC,
TRAC and hill-start assist con-
trol systems
●A sound may be heard from the
engine compartment when the
brake pedal is depressed repeat-
edly, when the hybrid system is
started or just after the vehicle
begins to move. This sound does
not indicate that a malfunction has
occurred in any of these systems.
●Any of the following conditions
may occur when the above sys-
tems are operating. None of these
indicates that a malfunction has
occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also
after the vehicle comes to a stop.
■ECB operating sound
ECB operating sound may be heard
in the following cases, but it does
not indicate that a malfunction has
occurred.
●Operating sound heard from the
engine compartment when the
brake pedal is operated.
●Operating sound heard from the engine compartment when one or
two minutes passed after the stop
of the hybrid system.
■Active Cornering Assist opera-
tion sounds and vibrations
When the Active Cornering Assist is
operated, operation sounds and
vibrations may be generated from
the brake system, but this is not a
malfunction.
■Automatic reactivation of TRAC
and VSC systems
After turning the TRAC and VSC
systems off, the systems will be
automatically re-enabled in the fol-
lowing situations:
●When the power switch is turned
off
●If only the TRAC system is turned
off, the TRAC will turn on when
vehicle speed increases
If both the TRAC and VSC sys-
tems are turned off, automatic re-
enabling will not occur when vehi-
cle speed increases.
■Operating conditions of Active
Cornering Assist
The system operates when the fol-
lowing occurs.
●TRAC/VSC can operate
●The driver is attempting to accel-
erate while turning
●The system detects that the vehi-
cle is drifting to the outer side
●The brake pedal is released
■Reduced effectiveness of the
EPS system
The effectivenes s of the EPS sys-
tem is reduced to prevent the sys-
tem from overheating when there is
frequent steering input over an
extended period of time. The steer-
ing wheel may feel heavy as a
result. Should this occur, refrain
from excessive steering input or
stop the vehicle and turn the hybrid
system off. The EPS system should
return to normal within 10 minutes.

4275-5. Using the driving support systems
5
Driving
■Secondary Collision Brake
operating conditions
The system operates when the SRS
airbag sensor detects a collision
while the vehicle is in motion.
However, the system does not oper-
ate when the components are dam-
aged.
■Secondary Collision Brake
automatic cancellation
The system is automatically can-
celed in any of the following situa-
tions.
●The vehicle speed drops to
approximately 0 mph (0 km/h).
●A certain amount of time elapses
during operation
●The accelerator pedal is
depressed a large amount
WARNING
■The ABS does not operate
effectively when
●The limits of tire gripping perfor-
mance have been exceeded
(such as excessively worn tires
on a snow-covered road).
●The vehicle hydroplanes while
driving at high speed on wet or
slick roads.
■Stopping distance when the
ABS is operating may exceed
that of normal conditions
The ABS is not designed to
shorten the vehicle’s stopping dis-
tance. Always maintain a safe dis-
tance from the vehicle in front of
you, especially in the following sit-
uations:
●When driving on dirt, gravel or
snow-covered roads
●When driving with tire chains
●When driving over bumps in the
road
●When driving over roads with
potholes or uneven surfaces
■TRAC/VSC may not operate
effectively when
Directional control and power may
not be achievable while driving on
slippery road surfaces, even if the
TRAC/VSC system is operating.
Drive the vehicle carefully in con-
ditions where stability and power
may be lost.
■Active Cornering Assist does
not operate effectively when
●Do not overly rely on Active
Cornering Assist. Active Corner-
ing Assist may not operate
effectively when accelerating
down slopes or driving on slip-
pery road surfaces.
●When Active Cornering Assist
frequently operates, Active Cor-
nering Assist may temporarily
stop operating to ensure proper
operation of the brakes, TRAC
and VSC.
■Hill-start assist control does
not operate effectively when
●Do not overly rely on hill-start
assist control. Hill-start assist
control may not operate effec-
tively on steep inclines and
roads covered with ice.
●Unlike the parking brake, hill-
start assist control is not
intended to hold the vehicle sta-
tionary for an extended period
of time. Do not attempt to use
hill-start assist control to hold
the vehicle on an incline, as
doing so may lead to an acci-
dent.

4285-5. Using the driving support systems
WARNING
■When the TRAC/ABS/VSC is
activated
The slip indicator light flashes.
Always drive care fully. Reckless
driving may cause an accident.
Exercise particular care when the
indicator light flashes.
■When the TRAC/VSC systems
are turned off
Be especially careful and drive at
a speed appropriate to the road
conditions. As these are the sys-
tems to help ensure vehicle stabil-
ity and driving force, do not turn
the TRAC/VSC systems off
unless necessary.
■Replacing tires
Make sure that all tires are of the
specified size, brand, tread pat-
tern and total load capacity. In
addition, make sure that the tires
are inflated to the recommended
tire inflation pressure level.
The ABS, TRAC and VSC sys-
tems will not function correctly if
different tires are installed on the
vehicle.
Contact your Toyota dealer for
further information when replacing
tires or wheels.
■Handling of tires and the sus-
pension
Using tires with any kind of prob-
lem or modifying the suspension
will affect the driv ing assist sys-
tems, and may cause a system to
malfunction.
■Secondary Collision Brake
Do not rely solely upon the Sec-
ondary Collision Brake. This sys-
tem is designed to help reduce
the possibility of further damage
due to a secondary collision, how-
ever, that effect changes accord-
ing to various conditions. Overly
relying on the system may result
in death or serious injury.

4295-6. Driving tips
5
Driving
5-6.Driving tips
Use fluids that are appropriate
to the prevailing outside tem-
peratures.
• Engine oil
• Engine coolant
• Power control unit coolant
• Washer fluid
Have a service technician
inspect the condition of the
12-volt battery.
 Have the vehicle fitted with
four snow tires or purchase a
set of tire chains for the front
tires.
*
Ensure that all tires are the same
size and brand, and that chains
match the size of the tires.
*: Tire chains cannot be mounted
on vehicles with 195/50R19 tires.
Winter driving tips
Carry out the necessary
preparations and inspec-
tions before driving the
vehicle in winter. Always
drive the vehicle in a man-
ner appropriate to the pre-
vailing weather conditions.
Preparation for winter
WARNING
■Driving with snow tires
Observe the following precautions
to reduce the risk of accidents.
Failure to do so may result in a
loss of vehicle control and cause
death or serious injury.
●Use tires of the specified size.
●Maintain the recommended
level of air pressure.
●Do not drive in excess of 75
mph (120 km/h), regardless of
the type of snow tires being
used.
●Use snow tires on all, not just
some wheels.
■Driving with tire chains
(except 195/50R19 tires)
Observe the following precautions
to reduce the risk of accidents.
Failure to do so may result in the
vehicle being unable to be driven
safely, and may cause death or
serious injury.
●Do not drive in excess of the
speed limit specified for the tire
chains being used, or 30 mph
(50 km/h), whichever is lower.
●Avoid driving on bumpy road
surfaces or over potholes.
●Avoid sudden acceleration,
abrupt steering, sudden brak-
ing and shifting operations that
cause sudden engine braking.
●Slow down sufficiently before
entering a curve to ensure that
vehicle control is maintained.
●Do not use LTA (Lane Tracing
Assist) system.
●Do not use LDA (Lane Depar-
ture Alert) system.

4305-6. Driving tips
Perform the following according
to the driving conditions:
Do not try to forcibly open a
window or move a wiper that
is frozen. Pour warm water
over the frozen area to melt
the ice. Wipe away the water
immediately to prevent it from
freezing.
 To ensure proper operation of
the climate control system
fan, remove any snow that
has accumulated on the air
inlet vents in front of the wind-
shield.
 Check for and remove any
excess ice or snow that may
have accumulated on the
exterior lights, outside rear
view mirrors, windows, vehi-
cle’s roof, chassis, around the
tires or on the brakes.
 Remove any snow or mud
from the bottom of your shoes
before getting in the vehicle. Accelerate the vehicle slowly,
keep a safe distance between
you and the vehicle ahead, and
drive at a reduced speed suit-
able to road conditions.

Turn automatic mode of the
parking brake off.
Otherwise, the parking brake
may freeze and not be able to
be released automatically.
Also, avoid using the following as
the parking brake may operate
automatically, even if automatic
mode is off.
• Brake hold system
Park the vehicle and shift the
shift position to P without set-
ting the parking brake. The
parking brake may freeze up,
preventing it from being
released. If the vehicle is
parked without setting the
parking brake, make sure to
block the wheels. Failure to
do so may be dangerous
because it may cause the
vehicle to move unexpect-
edly, possibly leading to an
accident.
 When the parking brake is in
automatic mode, release the
parking brake after shifting
the shift position to P.
( P.264)
NOTICE
■Repairing or replacing snow
tires
Request repairs or replacement of
snow tires from your Toyota
dealer or legitimate tire retailers.
This is because the removal and
attachment of snow tires affects
the operation of the tire pressure
warning valves and transmitters.
Before driving the vehicle
When driving the vehicle
When parking the vehicle

4315-6. Driving tips
5
Driving
If the vehicle is parked without
setting the parking brake,
confirm that the shift position
cannot be moved out of P.
 If the vehicle is left parked
with the brakes damp in cold
temperatures, there is a pos-
sibility of the brakes freezing.
Vehicles without 195/50R19
tires
Use the correct tire chain size
when mounting the tire chains.
Chain size is regulated for each
tire size.
Side chain:
0.12 in. (3 mm) in diameter
0.39 in. (10 mm) in width
1.18 in. (30 mm) in length
Cross chain: 0.16 in. (4 mm) in diameter
0.55 in. (14 mm) in width
0.98 in. (25 mm) in length
Vehicles with 195/50R19 tires
Tire chains cannot be mounted.
Snow tires should be used
instead.
Regulations regarding the use
of tire chains vary depending on
location and type of road.
Always check local regulations
before installing chains.
■Tire chain installation
Observe the following precautions
when installing and removing
chains:
●Install and remove tire chains in a
safe location.
●Install tire chains on the front tires
only. Do not install tire chains on
the rear tires.
●Install tire chains on front tires as
tightly as possible. Retighten
chains after driving 1/4 - 1/2 mile
(0.5 - 1.0 km).
●Install tire chains following the
instructions provid ed with the tire
chains.
WARNING
■When parking the vehicle
When parking the vehicle without
applying the parking brake, make
sure to chock the wheels. If you
do not chock the wheels, the vehi-
cle may move unexpectedly, pos-
sibly resulting in an accident.
Selecting tire chains
A
B
C
Regulations on the use of
tire chains (except
195/50R19 tires)
NOTICE
■Fitting tire chains
The tire pressure warning valves
and transmitters may not function
correctly when tire chains are fit-
ted.
D
E
F

4325-6. Driving tips