A DIAGNOSTIC DEVICE FOR A MULTI-VOLTAGE ON-BOARD ELECTRICAL DISTRIBUTION SYSTEM, A MULTI-VOLTAGE POWER SUPPLY AND A METHOD FOR OPERATING A MULTI-VOLTAGE ON-BOARD ELECTRICAL DISTRIBUTION SYSTEM

摘要

A diagnostic device (1) is proposed for a multi-voltage on-board electrical distribution system (10) for a motor vehicle, wherein the multi-voltage on-board electrical distribution system (10) comprises a first sub-network (11), to which a first voltage can be supplied, and at least one additional sub-network (12), to which at least one additional voltage can be supplied, wherein the first voltage is higher than the at least one additional voltage, and wherein the first sub-network (11) and the at least one additional sub-network (12) have a common mass connection (GM), in which at least one additional mass connection (GG) is provided, to which measuring means are assigned, which are furnished for measuring a flow of current via the at least one additional mass connection (GG), and diagnostic means (2) are provided, which are furnished for diagnosing a malfunction in the common mass connection (GM) and/or the at least one additional mass connection (GG), based upon the measured flow of current over the at least one additional mass connection (GG), dependent on at least one operating condition of the multi-voltage on-board electrical distribution system (10).