Plug in any OBD-II adapter and get plain-English explanations of every check engine code — with severity ratings and AI guidance, in under 60 seconds.
What you get
Every check engine code — including manufacturer-specific ones — decoded in under a second. Covers engine, transmission, brakes, airbag, and more. No cryptic codes, no guessing.
Every code ranked Safe / Monitor / Urgent / Critical. Know immediately whether you're looking at a loose gas cap or a towed-home situation.
Real-time fuel trims, O2 sensor readings, coolant temp, RPM, MAF flow. See what the sensor actually saw at the moment the code triggered.
Unknown or ambiguous codes get plain-English AI explanations — what caused it, how serious it is, and what to do next. No mechanic jargon.
Try it now
Run a full diagnostic scan right here in your browser. Demo mode shows real P0301 / P0420 data — no OBD-II adapter needed.
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FAQ
Any ELM327-compatible WiFi or Bluetooth adapter. Recommended: OBDLink CX, OBDLink MX+, and Vgate iCar Pro. Reading codes is non-invasive — it doesn't touch your car's settings or modules. See the full adapter guide →
For codes not in our local database of ~200 known DTCs, NexusCode sends only the code itself and brief context to OpenAI for a plain-English explanation. No VIN, no live telemetry, no location leaves the app, and there's a graceful fallback to a local explanation when the API is unavailable.
Free — read and clear codes, severity ratings, plain-English explanations of the ~200 known codes, and the full in-app demo.
Pro — everything in Free, plus freeze-frame capture, persistent multi-scan history, AI explanations of unknown or manufacturer-specific codes, and multi-vehicle profiles so you can track every car in the household.
Codes and severity ratings stay on your device. The only data we store server-side is the optional scan history you choose to save — a vehicle nickname, the DTC list, and a timestamp. No VIN is required. Read the full privacy policy, or delete your account at any time for a full wipe.