Skip to content

Hyundai Elantra CN7 (EU) not automatically fingerprinted — requires manual CN7 2021 override #3743

Description

@TheGoldenV

Describe the car bug

Car: Hyundai Elantra CN7 (2021), European-market build, with Smart Cruise Control (SCC).

Automatic car fingerprinting does not recognize this car at all on stock openpilot, so it cannot engage/drive normally. The only way to get it running is via sunnypilot, manually overriding the platform selection to HYUNDAI_ELANTRA_2021 (CN7). With that manual override, longitudinal and lateral control work correctly, including the OEM Smart Cruise Control interface.

This points to a firmware/ECU mismatch in the FW_VERSIONS fingerprint table for this platform rather than a real behavioral difference. EU-market CN7 units apparently ship ECU firmware versions that are not present in opendbc's fingerprint entries for HYUNDAI_ELANTRA_2021, so FW-based fingerprinting (Fingerprinting 2.0) never matches and the car falls back to unsupported instead of auto-selecting CN7 2021.

Attached is a public route from a normal drive with the manual CN7 2021 override active, for reference on this car's CAN/FW behavior.

Steps to reproduce:

  1. Install comma 4 / panda on a EU-spec Hyundai Elantra CN7 (2021, SCC-equipped).
  2. Power on and start the car with stock openpilot (no manual fingerprint override).
  3. Car is not recognized — fingerprinting fails to match HYUNDAI_ELANTRA_2021, so openpilot cannot engage properly.
  4. Manually forcing the CN7 2021 (HYUNDAI_ELANTRA_2021) platform in sunnypilot works correctly — confirming it is the right platform, just not reachable via automatic FW fingerprinting for this EU firmware revision.

Provide a route where the issue occurs

https://connect.comma.ai/4db9a4d26f328177/00000026--c5876b04d9

openpilot version

sunnypilot (fork) — exact release TBD, will confirm; base opendbc fingerprint tables are shared with stock openpilot so this is not fork-specific behavior

Additional info

Willing to help pull ECU firmware versions via UDS from this route (or a fresh one) to add proper entries to FW_VERSIONS in opendbc/car/hyundai/fingerprints.py, following the Fingerprinting guide. Happy to coordinate on Discord if that is a better place to work through it.

i told claude to do all this so idk what it did

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    bugcarrelated to opendbc/car/

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions