What we do
AutoDTCs.com decodes OBD-II diagnostic trouble codes (DTCs) into plain English. When a scanner — or your car's on-board computer — throws a code like P0420 or C1201, we tell you exactly what it means, what symptoms to look for, the most likely causes ranked by frequency, and what a typical repair costs.
We cover all four OBD-II systems:
- P-codes — Powertrain (engine, transmission, fuel, emissions)
- B-codes — Body (airbags, lighting, climate, comfort)
- C-codes — Chassis (ABS, brakes, steering, suspension)
- U-codes — Network (module communication, CAN bus)
Beyond generic SAE codes, we publish manufacturer-specific pages for popular makes including Toyota, Ford, Chrysler, Jeep, and others, sourced from factory service data.
Our methodology
Every code page on AutoDTCs.com is written from original research, not copied from a competitor's database. Our process:
- Start with the official definition.Each code entry uses the authoritative meaning from SAE J2012 (for generic codes) or the manufacturer's factory service manual (FSM) for brand-specific codes.
- Cross-check against real diagnostic logic. We compare the official definition against known failure patterns, common sensor behaviors, and real-world repair data to rank likely causes accurately — not just list every possible cause.
- Restate in plain English. Factory manuals are written for technicians. We rewrite everything for the vehicle owner: what it means, how serious it is, and whether you can safely continue driving.
- Review for accuracy. Content is reviewed against factory diagnostic logic before publication. We do not reproduce verbatim OEM text — all guidance is original and restated.
Who this site is for
AutoDTCs.com is built for vehicle owners who want to understand a trouble code before deciding whether to drive to the shop, which part to order, or how urgently to act. It is also useful for independent mechanics and enthusiasts who want a quick facts-first reference.
The site is free, ad-supported, and covers an international audience — OBD-II is a global standard used on virtually every petrol and diesel car sold since the late 1990s.
Disclaimer
AutoDTCs.com is an informational resource only. Code descriptions and repair guidance are provided to help you understand a fault — they are not a substitute for diagnosis by a qualified mechanic. If you are uncertain about any repair, always consult a professional. See our Terms of Use for full details.
Contact
Questions, corrections, or feedback? Get in touch.