a method to provide a highly intelligent , automated diagnostic system that identifies the need to replace specific parts to minimize machine downtime rather than require extensive service troubleshooting . in particular , a systematic , logical test analysis scheme to assess machine operation from a simple sensor system and to be able to pinpoint parts and components needing replacement is provided by a series of first level of tests by the control to monitor components for receiving a first level of data and by a series of second level of tests by the control to monitor components for receiving a second level of data . each of the first level tests and first level data is capable of identifying a first level of part failure independent of any other test . each of the second level tests and second level data is a combination of first level tests and first level data or a combination of a first level test and first level data and a third level test and third level data . the second level tests and second level data are capable of identifying second and third levels of part failure . codes are stored and displayed to manifest specific part failures .