The class of ad hoc networks is of great applicability for pervasive and mobile computing. As an ad hoc network has highly dynamic, variable underlying topologies, its mobility management has long been a challenging issue in the area of wireless networking. The localized fault diagnosis can be an effective strategy of the periodic topology control for mobility management applications by identifying fault status of each node. The main contributions of this paper are highlighted as follows: (1) We first establish a topological condition for recognizing whether or not a node is restrictively one-step f-identifiable in an ad hoc network, where f denotes the amount of faulty nodes that are tolerable in our condition. (2) Then we propose a robust comparison-based fault identification algorithm that is applicable to topology formation taken for the maintenance of ad hoc networks. (3) Numerical robustness evaluation is presented to figure out the scalability of the proposed algorithm.