A method is used to evaluate a camera-related subsystem in a digital network, e.g., aboard a vehicle or fleet, by receiving, via a camera diagnostic module (CDM), sensor reports from the subsystem and possibly from a door sensor, rain/weather sensor, or other sensor. The CDM includes data tables corresponding to subsystem-specific fault modes. The method includes evaluating performance of the camera-related subsystem by comparing potential fault indicators in the received sensor reports to one of the data tables, and determining a pattern of fault indicators in the reports. The pattern is indicative of a health characteristic of the camera-related subsystem. A control action is executed with respect to the digital network in response to the health characteristic, including recording a diagnostic or prognostic code indicative of the health characteristic. The digital network and vehicle are also disclosed.