CAN DBC for MAZDA MX-5 2015-2023 (ND1/ND2)

日本語はこちらから README.ja.md for Japanese users.

What's CAN DBC?

A nice database that makes raw CAN data readable!

A CAN DBC (DBC file) is a database file format that defines the relationship between raw CAN bus data (binary frames) and human-readable physical values.
It was developed by Vector and is widely used as the de facto standard in the automotive industry.

For a detailed explanation, see CSS Electronics:
A simple intro to DBC

This Repo is for MX-5 2015-2023 (ND1/ND2)

This repository provides CAN DBC files created through independent analysis of CAN bus communications for MAZDA MX-5 2015-2023 (ND1/ND2).

The DBC files are based on observations of real vehicle communication, log analysis, and cross-referencing with known specifications.
All contents represent independent investigation and estimation performed by an individual, and are not based on official manufacturer documentation.

Rather than aiming for a “finished” or definitive database, this project is intended to be grown collaboratively by sharing knowledge.
Intermediate and exploratory analysis results are intentionally included, with the expectation that the contents will continue to evolve over time.

Contents

• CAN DBC files for HS-CAN and MS-CAN
  • Signal definitions (ID, signal name, scale, offset, etc.)
  • Comments describing signal meaning, behavior, and underlying assumptions

The contents are primarily based on personal analysis.
As a result, many messages are currently defined only at a structural level, and some signals are still under verification.

Further refinement and expansion are expected as analysis progresses.
Issues for corrections or additional information, as well as pull requests supported by validation or evidence, are very welcome.

Target vehicles

This DBC is intended for the following vehicle.

• Manufacturer: MAZDA
• Model / Platform: MX-5 ND
• Model year: 2015-2023 (ND1/ND2)
• Bus type: HS-CAN (500 kbps), MS-CAN (125 kbps)

Other vehicle models and model years:

• There is a high level of similarity with other Mazda 6th-generation electrical architectures, but some differences may exist.
  • BCMM style vehicles show particularly strong similarities and should be mutually useful as references.
    • DEMIO/MAZDA2 (DJ/DL), CX-3 (DK)
  • FBCM / RBCM style vehicles have some differences in configuration, but are broadly similar in overall structure.
    • CX-5(KE), CX-5(KF), CX-9(TC), MAZDA3(BM/BN), MAZDA6(GJ/GL) etc.
• ND3 (2024 and later) vehicles appear to be significantly different and follow a substantially different architecture.

Note on Generation Naming Differences

The Mazda MX-5 (ND) uses different generation naming conventions
in Japan and in overseas markets.

In this repository, each README adopts the naming convention commonly used
in the language and region it targets.
As a result, the Japanese and English README files may use different generation names for the same model years.
The actual vehicle coverage is consistent between both documents.

Model years	Common naming in Japan	Common naming overseas (US/EU)
2015–2018	ND1 (early)	ND1
2018–2023	ND1 (late)	ND2
2024–	ND2	ND3

Tools Supporting DBC

• SavvyCAN
  An open-source and free tool. It enables powerful CAN bus analysis using DBC files.

• Vector CANdb++ / CANalyzer / CANoe, etc.
  These are the original tools from the company that developed the DBC format.
  They are fully enterprise-oriented tools and not intended for individual purchase,
  but they are the most widely used tools in development departments of automotive OEMs and Tier-1 suppliers.

Disclaimer

• The contents of this DBC are not official manufacturer documentation and are based on personal, hobbyist-level analysis.
  Accuracy and completeness are not guaranteed.
  The author assumes no responsibility for any damage or loss resulting from the use of this data.
• The analysis is primarily based on a Japanese-market ND2 late-model (990S, MY2022), with partial validation on ND1 vehicles.
  Differences may exist for ND1 vehicles (2015 to early 2018) and for vehicles intended for other markets.

In particular, when connecting to or transmitting messages on a vehicle CAN bus while the vehicle is in motion,
please do so only with sufficient knowledge and at your own responsibility.

Contributing

Contributions such as corrections, additional findings, or improvements are welcome.
Please use Issues or Pull Requests. By submitting a pull request, you agree that your contribution is licensed under CC-BY 4.0.

Helpful information includes:

• Target vehicle details
• Test conditions (driving state, user actions, etc.)
• Logs or supporting evidence

License

This work is licensed under the Creative Commons Attribution 4.0 International (CC-BY 4.0).

About the Author

This project was created by berumiya from Japan.
I enjoy customizing the electronics of my Mazda Roadster MY2022 "990S" (MX-5 Miata, ND model).
You can find more about my work on my SNS profile (all in Japanese): minkara.carview.co.jp