In this paper, we introduce a new knowledge based for fault detection and diagnosis using fuzzy logic approach and challenge approach in wireless Sensor Networks (WSNs). We develop a fault detection, isolation, and recovery algorithm based on the communication framework and show how this model works to diagnose fault nodes. We use a simple fuzzy knowledge based control approach to help diagnose faulty communication between sensor nodes which provide fault detection and isolation (FDI) to eliminate faulty communication behaviour nodes impact to senor networks. Moreover, our algorithm also concern erroneously behaves nodes tolerance can ensure that faulty nodes sharing incorrect data under certain quantities can be tolerate and eliminate in the network. Thus guarantee that data fusion in WSNs can gather reliable data from proper sinks only.