This article concentrates on the issue of fault detection in the networked system. Quantized output and event-triggered communication scheme are absorbed into the system analysis, and consequently, by designing a new quantizer with event triggering mechanism, a smooth communication environment without undesired system data is guaranteed. And the imperfect information interaction strategy induced asynchronous membership functions between system and fault detection observer are handled via a differential mean value theorem based approach. Combining the methods of Lyapunov stability theory and linear matrix inequality, we obtain the stability criterion of the T-S fuzzy systems closed by the predefined network channel. In the end, simulation examples demonstrate the validity of the fault detection method.