2023 TOYOTA PRIUS ECU

6237-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
7
When trouble arises
Open and secure the deck board. (P. 622)
Remove the tray.
Vehicles with compact spare tire: If the luggage cover is stowed ( P. 484),
remove both the tray and luggage cover.
Loosen the center fastener that
secures the spare tire.
Taking out the spare tire
1
2
Vehicles with compact spare
tire
Vehicles with full-size spare
tire
3
WARNING
■ When storing the spare tire
Be careful not to catch fingers or other body parts between the spare tire
and the body of the vehicle.

6327-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
WARNING
■When using the compact spare tire (if equipped)
● Remember that the spare tire provided is specifically designed for use with
your vehicle. Do not use your spare tire on another vehicle.
● Do not use more than one compact spare tire simultaneously.
● Replace the spare tire with a standard tire as soon as possible.
● Avoid sudden acceleration, abrupt steering, sudden braking and shifting
operations that cause sudden engine braking.
■ When the compact spare tire is attached (if equipped)
The vehicle speed may not be correctly detected, and the following systems
may not operate correctly:
Also, not only can the following system not be utilized fully, but it may even
negatively affect the drive-train components:
• E-Four (Electric Four wheel drive system)*
*: If equipped
■ Speed limit when using the compact spare tire (if equipped)
Do not drive at speeds in excess of 80 km/h (50 mph) when a compact
spare tire is installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to
observe this precaution may lead to an accident causing death or serious
injury.
■ After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their
storage location to reduce the possibility of personal injury during a collision
or sudden braking.
• ABS & Brake assist
• VSC
•TRC
• EPS
• AHB (Automatic High Beam)*
• PCS (Pre-Collision System)*
• LTA (Lane Tracing Assist)*
• Dynamic radar cruise control with
full-speed range*
• Cruise control*
• BSM (Blind Spot Monitor)*
• Toyota parking assist-sensor*
• Parking Support Brake function*
• Simple Intelligent Parking Assist
System*
• Toyota parking assist monitor*
• Navigation system*
• Panoramic view monitor*

6417-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
7
When trouble arises
Once the hybrid system has started, remove the jumper cables in
the exact reverse order from which they were connected.
To install the engine cover, conduct the removal procedure in
reverse. After installing, check that the fixed pins are inserted
securely.
Once the hybrid system starts, have the vehicle inspected at any
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer as soon as possible.
■ When opening the cover of the positive (+) battery terminal
 P. 523
■ 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 system 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.
■ When the 12-volt battery is removed or discharged
● Information stored in the ECU is cleared. When the 12-volt battery is
depleted, have the vehicle inspected at any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.
● Some systems may require initialization. (P. 679)
■ When removing the 12-volt 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 any
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
■ Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when
the vehicle is not in use, due to natural discharge and the draining effects of
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the hybrid system may be unable to start. (The
12-volt battery recharges automatically while the hybrid system is operating.)
8
9

6427-2. Steps to take in an emergency
PRIUS_OM_OM47F32E_(EE)
■ When recharging or replacing the 12-volt battery
● In some cases, it may not be possible to unlock the doors using the smart
entry & start system when the 12-volt battery is discharged. Use the wire-
less 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 you are unsure what mode the power switch was in before the 12-volt bat-
tery discharged, be especially careful when reconnecting the 12-volt battery.
● If the 12-volt battery discharges while the shift position is in P, it may not be
possible to shift the shift position to other positions. In this case, the vehicle
cannot be towed without lifting both front wheels because the front wheels
will be locked. ( P. 572)
■ When replacing the 12-volt battery
● Use a 12-volt battery that conforms to European regulations.
● Use a 12-volt battery that the case size is same as the previous one (LN1),
20 hour rate capacity (20HR) is equi valent (45Ah) or greater, and perfor-
mance rating (CCA) is equivalent (295A) or greater.
• If the sizes differ, the 12-volt battery cannot be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehi-
cle is not used is a short time, the 12-volt battery may discharge and the
hybrid system may not be able to start.
● For details, consult any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.

6728-2. Customization
PRIUS_OM_OM47F32E_(EE)■
Smart entry & start system and wireless remote control
(P. 177, 187)
■Smart entry & start system (P. 187)
*: If equipped
■
Wireless remote control (P. 177)
■Rear seat reminder (P. 180)
FunctionDefault
settingCustomized
setting
Operation signal
(emergency flashers)OnOff–OO
Open door reminder buzzer
(When locking the vehicle)OnOff––O
Time elapsed before the auto-
matic door lock function is
activated if a door is not
opened after being unlocked
30 seconds
60 seconds
––O
120 seconds
123
FunctionDefault
settingCustomized
setting
Smart entry & start system On Off – O O
Number of consecutive door
lock operations
*2 timesAs many as
desired––O
123
FunctionDefault
settingCustomized
setting
Wireless remote control On Off – – O
123
FunctionDefault
settingCustomized
setting
Rear seat reminder function On Off O – –
123