
476
PRIUS PRIME_OM_OM47A88U_(U)
5-5. Using the driving support systems
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corre-
sponding to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly,
or if the brakes are applied while driving on a slippery road surface
◆Brake assist
Generates an increased level of braking force after the brake pedal
is depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces.
◆Enhanced VSC (Enhanced Ve hicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery
road surfaces by controllin g steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads
To help enhance driving safety and performance, the following
systems operate automatically in response to various driving
situations. Be aware, however, that these systems are supple-
mentary and should not be relied upon too heavily when operat-
ing the vehicle.

PRIUS PRIME_OM_OM47A88U_(U)
4775-5. Using the driving support systems
5
Driving
◆Hill-start assist control
Helps to reduce the backward move ment of the vehicle when start-
ing on an uphill
◆EPS (Electric Power Steering)
Employs an electric motor to redu ce the amount of effort needed to
turn the steering wheel.
The slip indicator light will flash
while the TRAC/VSC/ABS sys-
tems are operating.
If the vehicle gets stuck in mud, di rt or snow, the TRAC system may
reduce power from the hybrid sy stem 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 sys-
tem back on.
When the TRAC/VSC/ABS systems are operating
Disabling the TRAC system

478
PRIUS PRIME_OM_OM47A88U_(U)
5-5. Using the driving support systems
■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-information display.
*
Press again to turn the systems back on.
*: Pre-collision brake assist and pre-collision braking will also be disabled.
The PCS warning light will come on and the message will be shown on the
multi-information display. ( →P. 654)
■ When the message is displayed on th e multi-information display show-
ing that TRAC has been disable d even if has not been pressed
TRAC cannot be operated. Contact your Toyota dealer.
■ Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and
hill-start assist control systems
●A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, 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 systems 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.
● Motor sound of the brake system heard from the front part of the vehicle
when the driver’s door is opened.
● Operating sound heard from the engine compartment when one or two min-
utes passed after the stop of the hybrid system.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.

509
PRIUS PRIME_OM_OM47A88U_(U)
6-1. Using the air conditioning system and defogger
6
Interior features
Remote Air Conditioning System
If the Remote Air Conditioning Sy stem is used while the charging
cable is connected to the vehicle, the reduction of charge in the hybrid
battery (traction battery) will be s uppressed to allow you to use elec-
tricity from an external power source.
Charging will be conducted automatically after the Remote Air Condition-
ing System is stopped.
Check the temperature setting of the air conditioning system.
( → P. 488, 499)
The Remote Air Conditioning System will operate in accordance with the
temperature settings of the air conditioning system.
Press and hold “A/C” on the wire-
less remote control to operate the
Remote Air Conditioning System.
The system will shut off if a door is
opened.
The system can be stopped by
pressing “A/C” twice.
The Remote Air Conditioning System uses electrical energy
stored in the hybrid battery (traction battery) and allows the air
conditioning to be operat ed by remote control.
Before leaving the vehicle
Activating the Remote Air Conditioning System

6678-2. Steps to take in an emergency
PRIUS PRIME_OM_OM47A88U_(U)
8
When trouble arises
■If “Shift System Malfunction See Owner’s Manual” is shown
Indicates a malfunction in the shift control system. Immediately have the sys-
tem inspected by your Toyota dealer.
The system may not operate properly.
■ If “Low 12-Volt Battery Apply Parking Brake Securely While Parking See
Owner’s Manual” is shown
Indicates that the 12-volt battery charge is insufficient. Charge or replace the
12-volt battery.
● When the message is shown, the hybrid system may not start or the shift
position may not be changed normally. (Coping method: →P. 669)
● After charging the 12-volt battery, the message may not go off until the shift
position is changed from P.
■ If “Shifting Unavailable Low 12-Volt Battery See Owner’s Manual” is
shown
Indicates that the shift position cannot be changed because the voltage of the
12-volt battery drops. Charge or replace the 12-volt battery.
(Coping method in the case the 12-volt battery is discharged: →P. 694)
■ If “Hybrid System Overheated. Re duced Output Power.” is shown
The message may be shown when driving under severe operating conditions.
(For example, when driving up a long steep hill or driving up a steep hill in
reverse.)
Coping method: →P. 700
■ If “Maintenance required for Traction battery cooling parts See owner’s
manual” is shown
There is a possibility that the filter may be clogged, the air intake vent may be
blocked or there may be a gap in the duct.
● When the air intake vents or filters are dirty, clean them by the procedures
on P. 562.
● When the air intake vents or filters are not dirty and the warning message is
shown, have the vehicle inspected at your Toyota dealer.
■ If “Hybrid Battery Low. Shift Ou t of to Recharge.” is shown
Message is displayed when the remaining charge for the hybrid battery (trac-
tion battery) is low.
As the hybrid battery (traction battery) can not be charged when the shift
position is in N, when stopped for long periods of time shift the shift position to
P.
■ If “Hybrid Battery Low Hybrid Syst em Stopped Shift to and Restart”
is shown
Message is displayed when the remaining charge for the hybrid battery (trac-
tion battery) is low, because vehicle has been shifted to N for a long period of
time.
When operating the vehicle, shift to P and restart the hybrid system.

688
PRIUS PRIME_OM_OM47A88U_(U)
8-2. Steps to take in an emergency
If the hybrid system will not start
One of the following may be the cause of the problem:
●The charging cable may be attached to the vehicle. ( →P. 136)
● The electronic key may not be functioning properly.
* (→ P. 690)
● There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ( →P. 92)
● There may be a malfunction in the immobilizer system.
* (→ P. 7 5 )
● There may be a malfunction in the shift control system.
*
( → P. 327, 669)
● The hybrid system may be malfunctioning due to an electrical prob-
lem such as electronic key battery depletion or a blown fuse. How-
ever, depending on the type of malfunction, an interim measure is
available to start the hybrid system. (→ P. 689)
● There is a possibility that the temperature of the hybrid battery
(traction battery) is extremely low (approximately below -22°F
[-30°C]). ( →P. 92, 326)
*: It may not be possible to shift the shift position other than P.
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( →P. 694)
● The 12-volt battery terminal con nections may be loose or corroded.
( → P. 587)
Reasons for the hybrid system not starting vary depending on
the situation. Check the follo wing and perform the appropriate
procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( →P. 324)
The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.

724
PRIUS PRIME_OM_OM47A88U_(U)
9-1. Specifications
This information has been prepared in accordance with regulations
issued by the National Highway Traffic Safety Administration of the
U.S. Department of Transportation.
It provides the purchasers and/or prospective purchasers of Toyota
vehicles with information on uniform tire quality grading.
Your Toyota dealer will help answe r any questions you may have as
you read this information.
■DOT quality grades
All passenger vehicle tires must c onform to Federal Safety Require-
ments in addition to these grades. Quality grades can be found
where applicable on the tire sidewall between tread shoulder and
maximum section width.
For example: Treadwear 200 Traction AA Temperature A
■Treadwear
The treadwear grade is a comparative rating based on the wear
rate of the tire when tested under controlled conditions on a speci-
fied government test course.
For example, a tire graded 150 wo uld wear one and a half (1 - 1/2)
times as well on the government course as a tire graded 100.
The relative performance of tire s depends upon the actual condi-
tions of their use. Performance may differ significantly from the norm
due to variations in driving habits, service practices and differences
in road characteristics and climate.
■Traction AA, A, B, C
The traction grades, from highest to lowest, are AA, A, B and C,
and they represent the tire’s ability to stop on wet pavement as
measured under controlled conditio ns on specified government test
surfaces of asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking
(straight ahead) traction tests and does not include cornering (turn-
ing) traction.
Uniform Tire Quality Grading

767Alphabetical index
PRIUS PRIME_OM_OM47A88U_(U)
Approach warning ................... 400
Assist grips .............................. 540
Audio input
*
Audio system*
Automatic air conditioning system ..... 488, 498 Air conditioning eco mode .......................... 490, 501
Air conditioning filter ............. 620
Automatic air conditioning system .... 488, 498
Eco score (A/C score)........... 228
Humidity sensor ............ 494, 505
Remote Air Conditioning System ............................... 509
S-FLOW mode .............. 489, 500
Automatic door locking
and unlocking systems ........ 270
Automatic High Beam ............. 343
Automatic light control system .................................... 341
AUX port
*
Auxiliary boxes ........................ 522
Back door ................................. 273
Back-up lights .......................... 635 Replacing light bulbs............. 636
Wattage ................................ 717
Battery (12-volt battery) .......... 587
Battery checking ................... 587
Exchanging ........................... 697
If the 12-volt battery is discharged .......................... 694
Preparing and checking before winter....................... 482
Warning light ......................... 653 Battery (traction battery) .......... 90
Air intake vent ......................... 91
Charging ............................... 102
Location .................................. 90
Specification ......................... 711
Status indicator ..................... 104
Blind Spot Monitor (BSM) ....... 408 Blind Spot Monitor function... 412
Rear Cross Traffic Alert
function............................... 415
Bluetooth
®*
Bottle holders .......................... 521
Brake Fluid ...................................... 716
Parking brake ....................... 337
Regenerative braking ............. 86
Warning light......................... 653
Brake assist ............................. 476
Brake Override System ........... 308
Break-in tips............................. 309
Brightness control Instrument cluster light control ......................... 182
BSM (Blind Spot Monitor) ....... 408 Blind Spot Monitor function... 412
Rear Cross Traffic Alert function............................... 415
Care .................................. 556, 561 Aluminum wheels ................. 557
Camera sensor ..................... 365
Exterior ................................. 556
Interior .................................. 561
Radar sensor ........................ 364
Seat belts.............................. 564
Water-repellent coating ........ 557
B
C
*: Refer to the “NAVIGATION SYSTEM OWNER’S MANUAL”.