Bus fault detection and isolation

A bus fault detection and isolation system and method is disclosed that can operate non-intrusively to detect and isolate faults in a bus, such as a dual redundant MIL STD 1553 bus. The system and method of the present invention can be configured to operate within a bus controller using existing system commands and variables defined for testing. No additional equipment may be needed to utilize the bus fault detection and isolation system and method, so no additional failure points are introduced and the bus is in an unmodified state while fault detection and isolation takes place. Further, the bus fault detection and isolation system and method of the present invention may use accumulator variables to detect an intermittent fault which may then be isolated later even if the fault condition is no longer present on the bus.