When current flows through the fuel pump relay, the relay turns ON and the fuel pump is driven. The fuel pump relay is built into the ETACS-ECU. When the ignition switch-ST signal is input, engine-ECU turns ON the power transistor for control of the fuel pump relay. As a result, power is supplied to the fuel pump. Also, if engine speed falls below a set value, the fuel pump relay is turned OFF. Thus, it deals with sudden stoppages such as engine stalling etc. by stopping the pump.