ECO mode TOYOTA PRIUS C 2020 Service Manual

4427-3. Do-it-yourself maintenance
PRIUS c_U
WARNING
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as
dangerous handling characteristics, which may lead to an accide nt
resulting in death o r serious injury.
●Do not mix tires of different ma kes, models or tread patterns.
Also, do not mix tires of re markably different treadwear.
●Do not use tire sizes other th an those recommended by Toyota.
●Do not mix differently constructed tires (radial, bias-belted o r bias-ply
tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have b een used on another vehicle.
Do not use tires if you do not kn ow how they were used previous ly.
●Do not tow if your vehicle has a compact spare tire installed.
■When initializing the tire pressure warning system
Do not operate the tire pressure warning reset switch without first
adjusting the tire inflation pressure to the specified level. O therwise, the
tire pressure warning light may not come on even if the tire in flation
pressure is low, or it may come on when the tire inflation pres sure is
actually normal.

4838-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
*1: Brake system warning buzzer: When there is a possible problem that could affect braking perf ormance,
the warning light will come on and a warning buzzer will sound.
*2: Parking brake engaged warning buzzer P. 207, 492
*3: Driver’s seat belt buzzer: Vehicles without a smart key system: The driver’s seat belt buzzer sounds
to alert the driver that his or her seat belt is not fastened. Once the power
switch is turned to the “ON” position, the buzzer sounds for 6 seconds. If
the vehicle reaches a speed of 12 mph (20 km/h), the buzzer sounds once.
If the seat belt is still unfastened after 24 seconds, the buzzer will sound
intermittently for 10 seconds. Then, if the seat belt is still unfastened, the
buzzer will sound in a different tone for 20 more seconds.
Vehicles with a smart key system: The driver’s seat belt buzzer sounds to
alert the driver that his or her seat belt is not fastened. Onc e the power
switch is turned to ON mode, the buzzer sounds for 6 seconds. I f the vehi-
cle reaches a speed of 12 mph (20 km/h), the buzzer sounds once. If the
seat belt is still unfastened after 24 seconds, the buzzer will sound intermit-
tently for 10 seconds. Then, if the seat belt is still unfasten ed, the buzzer
will sound in a different tone for 20 more seconds.
Front passenger’s seat belt buzzer:
The front passenger’s seat belt buzzer sounds to alert the fron t passenger
that his or her seat belt is not fastened. The buzzer sounds on ce if the
vehicle reaches a speed of 12 mph (20 km/h). If the seat belt i s still unfas-
tened after 24 seconds, the buzzer will sound intermittently fo r 10 seconds.
Then, if the seat belt is still unfastened, the buzzer will sou nd in a different
tone for 20 more seconds.
Tire pressure warning light When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 4 8 4 )
• Flat tire ( P. 505)
 Adjust the tire inflation pressure to the specified
level.
The light will turn off after a few minutes. In case
the light does not turn off even if the tire inflation
pressure is adjusted, have the system checked by
your Toyota dealer.
When the light comes on after blinking for 1 minute:
Malfunction in t he tire pressure warning system
(  P. 4 8 5 )
 Have the system checked by your Toyota dealer.
Warning lightWarning light/Details/Actions

4858-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U■
If the tire pressure warning system is not functioning
P. 440
■
If the tire pressure warning light frequently comes on after bl inking
for 1 minute
If the tire pressure warning light frequently comes on after bl inking for 1
minute when the power switch is turned to the “ON” position (ve hicles
without a smart key system) or the power switch is turned to ON mode
(vehicles with a smart key system) , have it checked by your Toyota
dealer.
■ Customization that can be configured at Toyota dealer
The vehicle speed linked seat belt reminder buzzer can be disab led. (Cus-
tomizable features: P. 560) However, Toyota recommends that the seat belt
reminder buzzer be operational to alert the driver and front pa ssenger when
seat belts are not fastened.
■ Warning buzzer
In some cases, the buzzer may not be heard because of noisy pla ce or an
audio sound.
WARNING
■ When the electric power steering 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 t he tire
inflation pressure immediately.
●If the tire pressure warning light comes on even after tire inf lation pres-
sure adjustment, it is probable that you have a flat tire. Chec k the tires.
If a tire is flat, change it with the spare tire and have the f lat tire
repaired by the nearest Toyota dealer.
●Avoid abrupt maneuvering and braking. If the vehicle tires dete riorate,
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.

4958-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_UIndicates that the EV drive mode is not avail-
able
*2
The reason the EV drive mode is not available
(the vehicle is idling, battery charge is low,
speed is higher than the EV drive mode operat-
ing speed range, accelerator pedal is
depressed too much) may be displayed.
A buzzer also sounds.
 Use the EV drive mode when it becomes
available.
Warning messageDetails/Actions

5038-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U

Power was turned off due to the
automatic power off function.
Next time when starting
the hybrid system,
increase the engine speed
slightly and maintain that
level for approximately 5
minutes to recharge the
12-volt-battery.
Once
The electronic key has a low
battery.
Replace the electronic key
battery. ( P. 451)
Once
The driver’s door was opened
and closed with the power
switch turned off and then the
power switch was put in
ACCESSORY mode twice with-
out the hybrid system being
started.
Press the power switch
while depressing the brake
pedal.
During a hybrid system starting
procedure in the event that the
electronic key was not function-
ing properly ( P. 520), the
power switch was touched with
the electronic key.
 Press the power switch
within 10 seconds of the
buzzer sounding.
Interior
buzzerExterior buzzerWarning messageDetails/Actions
(Flashes)

5198-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( P. 522)
● One or both of the 12-volt battery terminals may be disconnecte d.
(  P. 431)
Contact your Toyota dealer if the problem cannot be repaired, o r if repair
procedures are unknown.
When the hybrid system does not start, the following steps can be
used as an interim measure to sta rt the hybrid system if the power
switch is functioning normally.
Do not use this starting procedure except in case of emergency.
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power swi tch for about 15 seconds.
Even if the hybrid system can be started using the above steps, the
system may be malfunctioning. Hav e the vehicle inspected by your
Toyota dealer.
The interior lights and headlights do not turn on, or the horn
does not sound.
Emergency start function (vehicles with a smart key system)
1
2
3
4

5208-2. Steps to take in an emergency
PRIUS c_U
Use the mechanical key (P.
121) in order to perform the fol-
lowing operations (driver’s door
only):
Unlocks the doors
Locks all the doors
Turning the key rearward unlocks
the driver’s door. Turning the key
once again within 5 seconds
unlocks the other doors.
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Toyota emblem side
of the electronic key to the
power switch.
When the electronic key is
detected, a buzzer sounds and the
power switch will turn to ON mode.
When the smart key system is
deactivated in customization set-
ting, the power switch will turn to
ACCESSORY mode.
If the electronic key does not operate prop-
erly (vehicles with a smar t key system)
If communication between the electronic key and vehicle is
interrupted ( P. 143) or the electronic key cannot be used
because the battery is depleted, the smart key system and wire-
less remote control cannot be used. In such cases, the doors
can be opened and the hybrid system can be started by follow-
ing the procedure below.
Locking and unlocking the doors
1
2
Starting the hybrid system
1
2

5218-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
Firmly depress the brake pedal and check that is displayed
on the multi-information display.
Press the power switc h shortly and firmly.
In the event that the power s witch still cannot be operated, co ntact
your Toyota dealer.
■ Stopping the hybrid system
Shift the shift lever to P and press the power switch as you normally do when
stopping the hybrid system.
■ Replacing the key battery
As the above procedure is a temporary measure, it is recommende d that the
electronic key battery be replaced immediately when the battery is depleted.
( P. 451)
■ Changing power switch modes
Release the brake pedal and press the power switch in above.
The hybrid system does not start and modes will be changed each time the
switch is pressed. ( P. 193)
■ If the doors cannot be locked o r unlocked by the smart key syst em
Lock and unlock the doors by the mechanical key or wireless rem ote control.
■ When the electronic key does not work properly
●Make sure that the smart key system has not been deactivated in the cus-
tomization setting. If it is off, turn the function on.
(Customizable features: P. 560)
● Check if battery-saving mode is set. If it is set, cancel the f unction.
( P. 142)
3
4
3

5248-2. Steps to take in an emergency
PRIUS c_U
Vehicles without a smart key system:
Maintain the engine speed of the second vehicle and start the
hybrid system of your vehicle by turning the power switch to the
“ON” position.
Vehicles with a smart key system:
Maintain the engine speed of the second vehicle and start the
hybrid system of your vehicle by turning the power switch to ON
mode.
Make sure the “READY” indicator comes on. If the indicator does
not come on, contact your Toyota dealer.
Once the hybrid system has started, remove the jumper cables in
the exact reverse order from which they were connected.
Close the exclusive jump starting terminal cover, and reinstall the
fuse box cover to it s original position.
When installing, first hook the fuse box cover onto the two rea r tabs.
Once the hybrid system starts, have the vehicle inspected at yo ur
Toyota dealer as soon as possible.
6
7
8
9

5258-2. Steps to take in an emergency
8
When trouble arises
PRIUS c_U
■Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■ To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid s ystem is off.
● Turn off any unnecessary electrical components when the vehicle is running
at a low speed for an extended period, such as in heavy traffic .
■ Precautions when the 12-volt batte ry is discharged (vehicles with a
smart key system)
● In some cases, it may not be possible to unlock the doors using the smart
key system immediately after the 12-volt battery has been disco nnected and
reconnected. Use the wireless remote control or the mechanical key to lock
or unlock the doors.
● The hybrid system may not start on the first attempt after the 12-volt battery
has recharged but will start normally after the second attempt. This is not a
malfunction.
● The power switch mode is memorized by the vehicle. When the 12- volt bat-
tery is reconnected, the system will return to the mode it was in before the
12-volt battery was discharged. Before disconnecting the 12-volt battery,
turn the power switch off.
If the power switch was in ACCESSORY or ON mode before the 12-volt bat-
tery was discharged, the audio system and/or air conditioning system may
operate when the 12-volt battery is reconnected.
■ When the 12-volt battery is removed or discharged
● Information stored in the ECU is cleared. When the 12-volt batt ery is
depleted, have the vehicle inspected at your Toyota dealer.
● Some systems may require initialization. ( P. 565)
■ When removing the 12-vo lt battery terminals
When the 12-volt battery terminals are removed, the information stored in the
ECU is cleared. Before removing the 12-volt battery terminals, contact your
Toyota dealer.
■ Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gr adually even when
the vehicle is not in use, due to natural discharge and the dra ining effects of
certain electrical appliances. If the vehicle is left for a lon g time, the 12-volt
battery may discharge, and the hybrid system may be unable to s tart. (The
12-volt battery recharges automatically while the hybrid system is operating.)