A diagnostic method for an automated vehicle includes monitoring data from a first vehicle subsystem of a plurality of vehicle subsystems to establish a current operating zone for the first vehicle subsystem, transmitting a master diagnostic message with an anomalous status for the first vehicle subsystem in response to the current operating zone for the first vehicle subsystem being outside of an anomalous behavior boundary of a normal operating zone for the first vehicle subsystem for at least a predetermined period of time, the common master diagnostic message being transmitted to each vehicle subsystem of the plurality of vehicle subsystems, and adjusting operation of at least a second one of the plurality of vehicle subsystems in response to receiving the master diagnostic message with the anomalous status for the first vehicle subsystem. A related diagnostic system is also provided.