A method and system for performing diagnostics or software maintenance on a vehicle comprises recording high-fidelity data at the vehicle consistent with configuration files to support engineering analysis or diagnostics on vehicle components, systems or performance. Supplemental data is retrieved via a low bandwidth transmission at the vehicle to supplement the recorded high-fidelity data. The recorded high-fidelity data and retrieved supplemental data is processed to generate a diagnostic status report message from transmission to the central electronic data processing system. A data processor or central electronic data processing system organizes the diagnostic report message, the recorded high fidelity data and the retrieved supplemental data into a data mart or diagnostics database to support engineering analysis or diagnostics on vehicle components, systems or performance.