2021 Toyota Prius Prime Owner’s Manual

The 2021 Toyota Prius Prime is a great example of how hybrid technology is moving forward. It combines great gas mileage with cutting-edge style and technology. The Prius Prime is known for its eco-friendly performance. It has a plug-in hybrid powertrain that combines a gasoline engine and an electric motor. This gives the car a longer electric-only range and lower pollution. The 2021 Prius Prime shows that Toyota is committed to pushing the limits of hybrid excellence and moving toward a greener automobile future. It has a sleek and aerodynamic exterior, high-tech features, and a strong commitment to sustainability.

Plug-in hybrid system

Plug-in hybrid system features
The plug-in hybrid system is a system excellent in both the economical efficiencies of electric vehicles and the practicality of hybrid vehicles.

1. EV driving can be performed using electricity charged from an external power source.*
2. If the amount of electricity remaining in the hybrid battery (traction battery) becomes low, the vehicle is automatically controlled in such a way that it can be driven as a hybrid vehicle through the joint use of the gasoline engine.
3. The EV driving range will vary in accordance with conditions such as vehicle speed, the amount of charge remaining in the hybrid battery (traction battery), and the usage of the air conditioning system. The gasoline engine may also be used simultaneously in accordance with driving conditions.

The illustration is an example for explanation and may differ from the actual item.

1. Gasoline engine
2. Electric motor (traction motor)

Plug-in hybrid system operation mode
The plug-in hybrid system operates in the following modes. The multi-information display can be used to check which mode the plug-in hybrid system is currently being driven in.

EV mode
When a sufficient amount of electricity is remaining after charging*1, EV driving is performed using electricity stored in the hybrid battery (traction battery). When in EV mode, the EV drive mode indicator illuminates.

1. The amount of the remaining charge can be checked on the multi-information display etc.
2. Depending on the situation, EV driving may be canceled and both gas-line engines and electric motors are used.

EV auto mode
When a sufficient amount of electricity for EV driving remains in the hybrid battery (traction battery) after charging*, the operation mode can be switched to EV auto mode. Switching to EV auto mode makes powerful driving possible by using both the gasoline engine and electric motor in a driving condition that requires a large driving force, such as when passing a vehicle on a highway or driving on a steep slope. When in EV auto mode, the EV auto mode indicator illuminates. The amount of the remaining charge can be checked on the multi-information display etc.
HV mode
When in HV mode, the vehicle is driven using both the gasoline engine and electric motor (traction motor).

• If electricity needed for EV driving in EV mode or EV auto mode is not remaining, the operation mode will be automatically switched to HV mode.
• The operation mode can be switched to HV mode at any time by operating the switch to keep electricity for EV driving etc. Switching to HV mode when driving on a highway or when driving uphill is recommended in order to conserve battery power. When in HV mode, the EV drive mode indicator and EV auto mode indi-cator turn off. The EV driving range may reduce even after switching to HV mode. The EV driving range may reduce even after switching to HV mode.

Hybrid battery (traction battery) charge mode 
Electricity generated in the gasoline engine can be charged in the hybrid battery (traction battery) by switching to the hybrid battery (traction battery) charge mode when electricity needed for EV driving is not remaining.

• The system may not be able to switch to the hybrid battery (traction battery) charge mode due to the state of the plug-in hybrid system.
• Charging time differs depending on the driving state of the vehicle when driving in hybrid battery (traction battery) charge mode. When in the hybrid battery (traction battery) charge mode, the hybrid battery charge mode indicator illuminates. When in the hybrid battery (traction battery) charge mode, the hybrid battery can be charged while driving. However, the gasoline engine runs to charge the battery, and fuel consumption becomes higher compared with driving in HV mode.

Plug-in hybrid system operation mode selection switches
The plug-in hybrid system operation modes can be switched using the switches. If there is not enough charge remaining in the hybrid battery (traction bat-tery) to allow EV driving, EV/EV auto mode will not be selectable. The hybrid battery (traction battery) charge mode cannot be selected if the hybrid battery (traction battery) is almost completely charged.

Switching the plug-in hybrid system operation modes
Press the EV/HV mode selection switch or EV auto mode switch to change modes as the following table shows.

• When in EV mode, the EV drive mode indicator illuminates.
• When in EV auto mode, the EV auto mode indicator illuminates.
• When in HV mode, the EV drive mode indicator and EV auto mode indicator turn off.

Switching to the hybrid battery (traction battery) charge mode

Press and hold the switch. Take your hand off the switch once the hybrid battery charge mode indicator starts to blink. The hybrid battery charge mode indicator illuminates when the switch to the hybrid battery (traction battery) charge mode is complete. When the hybrid battery (traction battery) is fully charged, the hybrid battery (traction battery) charge mode is automatically canceled and the operation mode will be switched to HV mode.
The hybrid battery (traction battery) charge mode will be canceled by pressing the EV/HV mode selection switch or EV auto mode switch. The maximum charge amount in the hybrid battery (traction battery) charge mode is approximately 80% of the fully charged capacity for charging from an external power source.

• If the plug-in hybrid system operation mode cannot be changed
  In the following situations, the plug-in hybrid system operation mode cannot be changed even if the EV/HV mode selection switch or EV auto mode switch is pressed. (In this case, the warning message is displayed on the multi-infor-mation display when the switch is pressed.)
  • When electricity needed for EV driving is not remaining (when in EV/EV auto mode)
  • When the traction battery is almost completely charged (hybrid battery [trac-tion battery] charge mode)
• When switching from EV mode to another mode using the switch When the power switch is turned off, operation mode switching is canceled and the system returns to EV mode the next time the vehicle is started.
• Hybrid battery (traction battery) charge mode
  • The following may occur to protect the system, etc.
    • Cannot switch to hybrid battery (traction battery) charge mode or cannot cancel it
    •  The gasoline engine does not start or stop even after switching to hybrid bat-tery (traction battery) charge mode
  • If a load on the system is large, such as when the power consumption of the air conditioning system is large or when the temperature of the engine cool-ant is high, it may take longer time than usual to charge using the hybrid bat-tery (traction battery) charge mode or charging to the hybrid battery (traction battery) may not be performed.

Control when driving in each mode

• When in EV/EV auto mode
  In EV/EV auto mode, EV driving (driving using only the electric motor)* is possible. However, depending on the situation, EV driving may be canceled and both gasoline engines and electric motors are used (P. 95). Also, if a little electricity is remaining in the hybrid battery (traction battery), HV mode is automatically selected. To drive in EV/EV auto mode for long, observe the following.
  • Avoid sudden acceleration and sudden deceleration, and be sure to drive smoothly.
    If you repeatedly accelerate, the hybrid battery (traction battery) charge will deplete quickly. Also, EV driving may be canceled by rapid acceleration or vehicle speed.
  • Restrain your speed as much as possible. The distance that can be driven in EV/EV auto mode will reduce considerably at high speeds.
• When in HV mode
  The vehicle can be used in the same way as a standard hybrid vehicle.
  In HV mode, controls are primarily carried out as follows in accordance with the driving conditions.
  • The gasoline engine stops* when the vehicle is stopped.
  • During start-off, the electric motor (traction motor) drives the vehicle.
  • During normal driving, the gasoline engine and electric motor (traction motor) are controlled effectively, and the vehicle is driven with optimum fuel efficiency. Also, when necessary, the electric motor (traction motor) operates as an electrical generator to charge the hybrid battery (traction battery).
  • When the accelerator pedal is depressed heavily, drive force from both the gasoline engine and the electric motor (traction motor) is used to accelerate. When the hybrid battery (traction battery) requires charging or the engine is warming up, etc., the gasoline engine will not automatically stop.
• When braking (regenerative braking)
  • The electric motor (traction motor) charges the hybrid battery (traction battery).
  • The EV driving range can be extended by actively using this regenerative braking to store electricity in the hybrid battery (traction bat-tery).
  • Moreover, as fuel consumption is also reduced when in HV mode, the regenerative braking system can be used effectively.

FAQ’s