Motor vehicle on-board power supply system comprising - a battery , - a plurality of consumers , - a primary fuse , - a plurality of paths via which the primary fuse , which is electrically coupled to the battery , is electrically coupled in series with each one of the consumers , wherein each path comprises at least one of a plurality of secondary fuses , wherein the primary fuse and the secondary fuses are designed as reversible fuses and a control device of the motor vehicle on-board power supply system is configured to access said fuses to determine whether a fault has arisen in the motor vehicle on-board power supply system , said fault satisfying a triggering criterion at least for one of the fuses comprised by at least two of the paths , and, in this case, to selectively actuate the fuses in such a way that the fault-free paths are identified and the fuses in the fault-free paths are subsequently switched on again, characterized in that - the secondary fuses are arranged in a plurality of fuse layers , which each comprise a plurality of parallel-connected secondary fuses , in such a way that individual secondary fuses in one of the fuse layers are electrically coupled in series with a plurality of secondary fuses of another fuse layer and are therefore comprised by a plurality of the paths , and - the control device is configured, for the purpose of identifying the fault-free paths , to individually check only the paths having the at least one fuse for which the triggering criterion is satisfied in a prescribed order and: • to subsequently switch on the fuses of all the fault-free paths identified in the process again, or • as soon as a path having the at least one fuse for which the triggering criterion is satisfied has been identified, to switch on the fuses of all the other paths . - a battery , - a plurality of consumers , - a primary fuse , - a plurality of paths via which the primary fuse , which is electrically coupled to the battery , is electrically coupled in series with each one of the consumers , wherein each path comprises at least one of a plurality of secondary fuses , wherein the primary fuse and the secondary fuses are designed as reversible fuses and a control device of the motor vehicle on-board power supply system is configured to access said fuses to determine whether a fault has arisen in the motor vehicle on-board power supply system , said fault satisfying a triggering criterion at least for one of the fuses comprised by at least two of the paths , and, in this case, to selectively actuate the fuses in such a way that the fault-free paths are identified and the fuses in the fault-free paths are subsequently switched on again, characterized in that - the secondary fuses are arranged in a plurality of fuse layers , which each comprise a plurality of parallel-connected secondary fuses , in such a way that individual secondary fuses in one of the fuse layers are electrically coupled in series with a plurality of secondary fuses of another fuse layer and are therefore comprised by a plurality of the paths , and - the control device is configured, for the purpose of identifying the fault-free paths , to individually check only the paths having the at least one fuse for which the triggering criterion is satisfied in a prescribed order and: • to subsequently switch on the fuses of all the fault-free paths identified in the process again, or • as soon as a path having the at least one fuse for which the triggering criterion is satisfied has been identified, to switch on the fuses of all the other paths . • to subsequently switch on the fuses of all the fault-free paths identified in the process again, or • as soon as a path having the at least one fuse for which the triggering criterion is satisfied has been identified, to switch on the fuses of all the other paths . <EOS>