Computer assisted vehicle service featuring signature analysis and artificial intelligence

Claim 1

A diagnostic method for use in diagnosing a vehicle utilizing a diagnostic system, the vehicle having an on-board computer control system for monitoring and controlling vehicle functions and the diagnostic system including a technician terminal having a diagnostic controller for processing diagnostic signals representative of vehicle conditions, said controller having data entry means, data output means and storage means for storing vehicle parameters and diagnostic routines and said terminal having a display means for providing instructions for fault repair sequences, said method comprising the steps of: (1) displaying a main menu on said display means from which a vehicle setup is initiated including connecting the vehicle to the terminal and identifying the vehicle and any vehicle options; (2) utilizing a Fault Detection Procedure for detecting vehicle malfunctions by interrogating data received from said on-board computer during different vehicle states: ignition on (not running), engine cranking, engine idling and engine at higher speed and comparing said data with known parameters in said diagnostic controller storage means, any faults detected being stored in a fault table by fault code; (3) analyzing by a Fault Analysis Procedure the detected fault codes stored in the fault table by comparison with fault codes stored in a Fault Analysis Table to indicate a specific component suspected of being at fault, the Fault Analysis Table being periodically up-dated from a host data base by statistical analysis of prior service reports and the Fault Analysis Procedure supplying all fault codes in the Fault Analysis Table that match one or more of those provided by the Fault Detection Procedure; (4) accessing and selecting in a Fault Sequencing Procedure, for each fault supplied by the Fault Analysis Procedure, one or more isolation procedures stored in a light in said diagnostic controller, such list each being related to a particular component in said vehicle and also being periodically updated from said host data base, the Fault Sequencing Procedure initiating execution of the procedure at the top of the list; (5) utilizing said selected Fault Isolation Procedure and additional Fault Isolation Procedures in said list for testing of a related part in said vehicle by providing guidance via said display means for repairing, replacing or adjusting the related component.