Owing to the outstanding commercial value, electric-drive-reconstructed onboard chargers (EDROCs) have been a hotspot of research in electric vehicle (EV) field. This paper studies the fault diagnosis scheme and fault-tolerant control of a six-phase EDROC, considering the single-phase open-circuit condition. At first, the circuit topology and the basic operation principle of the six-phase EDROC are explained. Then, a simple fault diagnosis scheme is proposed for the open-circuit fault. The proposed scheme is composed of two parts, namely the fault detection and the fault localization, which are realized by estimating the derivative of the phase of winding current vector and judging the polarity of winding currents, respectively. Thereafter, the fault-tolerant control of the considered single-phase open-circuit fault is concerned. The amplitudes and phases of stator currents are adjusted, acquiring the purposes of balanced grid currents and non-generation of rotating filed. At last, an experimental test rig is built and the results verify the fault diagnosis scheme and the fault-tolerant control proposed in this work.