•  The PCM increases or decreases the field coil excitation current by sending a duty signal to the power transistor built into the generator.

•  The PCM changes the duty ratio of the duty signal to change the energization time of the power transistor. As a result, field coil excitation current is changed. For example, when the battery positive voltage drops, the duty ratio of the duty signal sent to the power transistor is larger, increasing the field coil excitation current.

•  To maintain optimum battery voltage, the PCM increases and decreases the field coil excitation current.

•  The generator rotation speed is calculated based on the ratio between the generator pulley and eccentric shaft pulley, and the engine speed.

•  The target output current is calculated from the difference obtained by comparison between present battery positive voltage and target battery positive voltage (regulated voltage), calculated based on the IAT, engine speed, and vehicle speed.

•  When an electrical load is applied, power consumption increases and the battery positive voltage drops, increasing the target engine speed at idling.

•  The PCM calculates the target excitation current based on the battery charge condition. The battery charge condition is estimated based on the battery charge/discharge flow from the electrical current sensor.

•  During deceleration fuel-cut, the PCM increases the generator voltage and stores electricity in the battery. At times other than deceleration, the PCM enables electric discharge from the battery to reduce the generator load.

•  If the electrical current sensor is malfunctioning (DTC P1515:00 is stored), the PCM, as in the past, calculates the target excitation current based on the targeted generator current (target generated current) and the generator rotation speed at that time.