Volt

Hybrid Modes of Operation Description

This vehicle is an Extended Range Electric Vehicle. It uses an electric propulsion system to drive the vehicle at all times. Electricity is the vehicle's primary source of energy, while gasoline is the secondary source.

The vehicle has two modes of operation - Electric and Extended Range. In both modes, the vehicle is propelled by the electric motors that are internal to the transmission. Electrical energy is converted into mechanical energy to drive the wheels and propel the vehicle. The vehicle's performance remains the same in either mode.

This overview is not a comprehensive list of all aspects of the Extended Range Electric Vehicle. Refer to Automatic Transmission 4ET50 Electronic Component Description for information regarding transmission operation. More detailled and comprehensive information is also available through the dealer training programme.

Electric Mode is the primary mode of operation for this vehicle. While in electric mode the vehicle is powered by electrical energy stored in the high-voltage battery. The vehicle can operate in this mode for a range of up to 40-80 km (25-50 miles) until the battery has reached a low state of charge.

When the vehicle reaches the end of its electric range, it switches to extended range mode. In this mode, electricity is produced by the motor generator which is driven by the internal combustion engine (ICE). This secondary source of electric power extends the vehicle range. Operation will continue in extended range mode until the vehicle can be plugged in to recharge the high-voltage battery and restore electric mode.

The high-voltage battery will continue to provide some power and work together with the ICE to provide peak performance when it is required, such as driving up a steep incline or during high acceleration. The high-voltage battery will not be recharged while in extended range mode.

This vehicle does not use a 12 V starter motor to crank the ICE. A much more powerful 300 V motor/generator located within the transmission is utilised to crank the ICE. The 300 V drive motor generator can rotate the ICE to operating speed (800 RPM) within just a few hundred milliseconds. The 300 V drive motor generator allows near-instant starting of the ICE.

The vehicleis on-board computers determine when the ICE needs to run. Some of the normal vehicle conditions that force the ICE to run are:

When the bonnet is open, the ICE will run without turning off. The high-voltage battery is neither charged nor discharged when this occurs.

Some high-voltage battery faults will cause the ICE to run without turning off.

The Service Mode is available for service and diagnostics, and to verify the proper operation of the MIL and may be required for emission inspection purposes. With the vehicle off, and the brake pedal not applied, pressing and holding the POWER button for more than 5 seconds will place the vehicle in Service Mode. The instruments and audio systems will operate as they do in ON/RUN, but the vehicle will not be able to be driven. The propulsion system will not start in Service Only Mode.

If the vehicle runs out of fuel, or the power inverter module has detected the ICE will not start due to a malfunction, the vehicle can continue to be driven in electric mode.

Engine Maintenance Mode

Engine maintenance mode runs the engine to keep it in good working condition when the vehicle has been operated in electric mode only for a prolonged period. Engine maintenance mode will run the ICE, even if the drive motor battery state of charge is sufficient to operate the vehicle in electric mode.

Fuel Maintenance Mode

When only electric mode is used for a prolonged period, fuel maintenance mode will run the ICE to use up old fuel. The ICE will run until enough fresh fuel is added or a low fuel level is detected. During fuel maintenance mode the ICE may cycle on and off.

When the vehicle is coasting or braking the power inverter module may operate the drive motor generator in an electrical generation mode. Operating as electrical generator, the drive motor generator exerts a driveline load that helps to slow the vehicle. The electrical energy that the drive motor generator creates is transferred by the drive motor generator power inverter module to the drive motor generator battery assembly. Constant communication between the power inverter module and the electronic brake control module allows the blending of regenerative braking force with hydraulic braking force.