A diagnostic scan tool is provided including a connect/configure module for establishing a communication link between the scan tool and a vehicle electronic control unit (ECU). A vehicle specification module operates to identify a vehicle under test in response to receipt of a vehicle identification number (VIN). A trouble code module retrieves digital trouble codes (DTCs) from the ECU. A freeze frame data module retrieves freeze frame data from the ECU, the retrieved freeze frame data being functionally associated with a highest priority DTC. A database lists possible vehicle defect solutions, indexed to the VIN and the DTCs. A digital signal processor is operative to derive the highest priority DTC from analysis of the retrieved freeze frame data. The digital signal processor further being operative to regulate selection of a most likely vehicle defect solution associated with the VIN and the highest priority DTC.