HKG: Car Port for Kia Carnival 2025-26 HDA II (ICE + Hybrid)

[iwilliamlee]

Checklist

• added entry to CarInfo in opendbc/car/hyundai/values.py
• test route added to routes.py
• route with stock system: N/A
• route with openpilot: 64884eacd32fec89/0000009c--f9ab362581 (segment 12 used in routes.py; engaged drive on a 2026 Carnival Hybrid HDA II)
• harness Type: Hyundai Q
• architecture: CAN-FD

Link to all physical parts during installation

• comma 4
• car harness kit
  • Hyundai Q

---

Summary

Supersedes #1558 (open since Dec 2024). Combines @sunnyhaibin's original 2025 Carnival HDA II car port with full 2025-26 hybrid coverage and the safety changes required to actually drive it.

Three commits:

1. HKG: Car Port for Kia Carnival 2025-26 HDA II — adds 2025 ICE + 2025/2026 hybrid fingerprints to KIA_CARNIVAL_4TH_GEN, dynamic HYBRID detection (existing 0xFA in ECAN), moves CANFD_ALT_BUTTONS detection out of the non-LKA-steering branch so it applies to HDA2 cars too. Drops the static CANFD_RADAR_SCC platform flag in favor of the existing per-vehicle SCC detection. Carries Co-Authored-By: Jason Wen for sunnyhaibin's original work in HKG: Car Port for Kia Carnival 2025 (HDA2) #1558.

2. hyundai_canfd: ALT_BUTTONS support for LKA-steering safety — extends Hyundai CAN-FD safety to handle the 0x1aa cruise-button address on the LKA-steering paths. Previously the LKA-steering init paths assumed standard 0x1cf buttons and would block any TX of 0x1aa; HDA2 cars without 0x1cf (e.g. 2025-26 Kia Carnival HDA II) need ALT_BUTTONS routing. Includes new test classes for LKAS + 0x1aa, LKAS_ALT + 0x1aa, and the longitudinal variant.

3. HKG: test route for Kia Carnival Hybrid 2025-26 HDA II — adds the engaged-drive test route entry to routes.py.

Why this isn't just #1558 rebased

#1558 covers the 2025 model year and treats hybrid detection via FW string prefix on the older 0x105-based hybrid logic. Since then, commaai/master moved hybrid detection to 0xFA in ECAN (works on this car — verified) and the Carnival 4th-gen platform was renamed. This PR rebases onto current master and adds:

• 2026 model year FW (KA4HMFC ... 99210-R0700 250324) — not in HKG: Car Port for Kia Carnival 2025 (HDA2) #1558
• Safety patch for HDA2 + ALT_BUTTONS — without this, every TX of 0x1aa is blocked by the panda's safety, so the car can't be driven via openpilot. HKG: Car Port for Kia Carnival 2025 (HDA2) #1558 doesn't touch safety.
• Safety tests for the new paths
• Test route from the 2026 hybrid

Verification

• Safety unit tests pass — 1086 tests (105 new for the LKA-steering + ALT_BUTTONS combinations); existing-platform behavior unchanged
• MISRA-clean — safety patch reviewed via cppcheck --addon=misra
• Real-rlog replay — validated against 5 segments of an engaged drive on a 2026 Carnival Hybrid HDA II:
  • 0 invalid RX across all segments (the new HYUNDAI_CANFD_ALT_BUTTONS_RX_CHECKS(1) for LKA-steering paths correctly accepts 0x1aa)
  • 0 0x1aa ever blocked on TX (the new TX hook + msg sets correctly route alt cruise buttons)
  • Mid-drive segments (e.g. seg 12) pass cleanly with all TX approved while controls allowed
• carParams sanity — the rlog's recorded safetyParam=178 decomposes cleanly to HYBRID_GAS | CANFD_LKA_STEER_MSG | CANFD_ALT_BUTTONS | CANFD_LKA_STEER_MSG_ALT, which our new code produces from the rlog's CAN data via dynamic detection

Bus / FW evidence (from rlog)

	bus 1 (E-CAN)	bus 2 (CAM)
0x110 LKAS_ALT	–	✅
0x362 CAM_0x362	–	✅
0x1cf standard buttons	–	–
0x1aa ALT_BUTTONS	✅	–
0xFA hybrid signal	✅	–
0x1ba BSM	✅	–

ADAS ECU 0x730 present (KA4 FBL6 1.00 1.00 250305) — confirms HDA2 with ADAS Driving ECU.

Credits

Thanks to @sunnyhaibin / Jason Wen for the original car port in #1558, and the community 2025 Kia Carnival (HDA2) owners (reasonableperson_29247, breadley4090, ianik66 on Discord) for the original validation. Hybrid validation by @iwilliamlee on a 2026 Carnival Hybrid HDA II.

[github-actions]

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  • the goal is clearly stated in the description
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[github-actions]

Car behavior report

Replays driving segments through this PR and compares the behavior to master.
Please review any changes carefully to ensure they are expected.

Testing 260 segments for: HYUNDAI_AZERA_HEV_6TH_GEN, HYUNDAI_ELANTRA_GT_I30, HYUNDAI_ELANTRA_2021, HYUNDAI_ELANTRA_HEV_2021, HYUNDAI_GENESIS, HYUNDAI_IONIQ, HYUNDAI_IONIQ_HEV_2022, HYUNDAI_IONIQ_EV_2020, HYUNDAI_IONIQ_PHEV_2019, HYUNDAI_IONIQ_PHEV, HYUNDAI_KONA_2022, HYUNDAI_KONA_EV, HYUNDAI_KONA_EV_2022, HYUNDAI_KONA_EV_2ND_GEN, HYUNDAI_SANTA_FE, HYUNDAI_SANTA_FE_2022, HYUNDAI_SANTA_FE_HEV_2022, HYUNDAI_SANTA_FE_PHEV_2022, HYUNDAI_SONATA, HYUNDAI_SONATA_LF, HYUNDAI_STARIA_4TH_GEN, HYUNDAI_PALISADE, HYUNDAI_SONATA_HYBRID, HYUNDAI_IONIQ_5, HYUNDAI_IONIQ_6, HYUNDAI_TUCSON_4TH_GEN, HYUNDAI_SANTA_CRUZ_1ST_GEN, HYUNDAI_CUSTIN_1ST_GEN

✅ 0 changed, 260 passed, 0 errors

[iwilliamlee]

The test_models (2) failures are all the same — segment 12 of 64884eacd32fec89/0000009c--f9ab362581 needs to be onboarded to the openpilotci bucket.

Status from my end:

• Route is public on connect.comma.ai (is_public: true per the comma API)
• All 17 qlog segments uploaded to commadata2
• Route resolves via comma_api_source with a signed URL (verified locally)

The CI's openpilotci_source doesn't have it yet, and comma_api_source likely needs a JWT my CI doesn't have. Could a maintainer add segment 12 to the openpilotci bucket?

Local validation done while preparing this PR:

• Safety unit tests: 1086 pass (105 new for LKA-steering + ALT_BUTTONS combinations)
• MISRA-clean (cppcheck --addon=misra)
• safety_replay against the qlog: 0 invalid RX, 0 0x1aa TX blocked across 5 segments. Mid-drive segments (e.g. seg 8, 12) pass cleanly with all TX approved while controls allowed
• carParams from the rlog decompose cleanly to HYBRID_GAS | CANFD_LKA_STEER_MSG | CANFD_ALT_BUTTONS | CANFD_LKA_STEER_MSG_ALT (safetyParam=178), which the new dynamic-detection code in this PR produces from the qlog's CAN data

Happy to share the rlog directly or capture additional data if needed. Drive metadata: 16 minutes engaged on a 2026 Kia Carnival Hybrid HDA II, captured 2026-05-06 PDT.