Abstract: In a method and apparatus for testing subsystem and/or system performance of an electronic printer, a controller uses an electronic scanning system bitmap representing an image to be printed to determine locations to be sensed by a plurality of sensors. The sensors are strategically located throughout the printing apparatus and are adapted to sense particular attributes in the designated image areas during the imaging process. The sensed image characteristics are compared with predetermined model characteristics, and the outputs are adjusted in accordance with the comparison to the model characteristics. In addition to the control function just described, the controller uses the information about the image contained in the image bitmap to determine the location and timing for the sensors, thereby enabling pre- and post-transfer testing without the printing of test pages or test patches.