An electronic diagnostic device for testing electronic monitoring tags for devices such as replaceable modules for a printing apparatus includes a tag reader with a reader wireless communication element. The tag reader is adapted to read tag diagnostic information from an electronic monitoring tag. The electronic diagnostic device further includes a data processor in communication with the tag reader. The data processor is adapted to determine from the tag diagnostic data whether the electronic monitoring tag is operating within predetermined parameters, to identify one of a predetermined set of error categories if the electronic monitoring tag is operating outside the predetermined parameters, and to generate error category information. The electronic diagnostic device further includes a results communication element adapted to communicate the error category information generated by the data processor. The diagnostic device may also communicate correction information to the electronic monitoring tag.