To maximize the energy productivity, effective in-field detection and real-time control of defective thermoelectric modules (TEMs) are critical in constituting a thermoelectric generation system (TEGS). In this paper, autonomous and distributed sensor nodes are designed to implement the wireless TEM management in terms of the measurement criteria of defective TEMs formulated for series-parallel-connected TEM arrays and the control scheme based on the TEM-oriented switches. The instrumentation of a TEGS prototype and the design of the embedded software associated with the sensor nodes are described, respectively. Defective and potentially healing conditions are dynamically monitored by a voltage sensor node and a temperature sensor node, both of which can judge the defective TEM and decide the related switching actions in a nearly independent way. The periodical wireless transmission from the nodes to a base station is no longer necessary, and with the minimized amount of communication signals, the battery lifetime of the distributed nodes can be significantly prolonged. In the experimental tests, the autonomous sensor nodes successfully disconnect and reconnect the defective TEMs, where a considerable power improvement is illustrated with the proposed measuring method and setup.