OBD-II PC Diagnostics — Adapter Setup, Protocols and Data Troubleshooting Unspecified

Use this thread for serial-port setup, ELM327 or compatible interface detection, generic trouble codes, monitor readiness, freeze-frame and live-data questions. Include the vehicle year, engine, adapter model, driver, selected COM port and negotiated protocol; remove VIN and customer details. Component scope, setup guidance and download are provided in the resource below.