feat(v0.14.5): n52 + n54 — swap local:10 oil for obd:5C + add 3 fuel-rate / runtime PIDs

[ohgeeceee]

Summary

Tier A, data only. v0.14.5 slice 1 of 3. Generalises the
v0.14.2 N62 slice 1 (PR #175) and v0.14.3 N62 slice 2 (PR
#186) pattern to the N52 / N54 E-series family that the
existing community profiles already cover but that v0.14.2
explicitly deferred to "the next cycle after N62 wraps up."

What this PR adds

For each of the two profile files, the same 4-entry
enrichment:

1. Oil-temp swap — replace the unverified local:10
   placeholder (labelled [UNVERIFIED placeholder]) with
   the standard SAE J1979 PID 0x5C (engine oil temperature,
   byte - 40 °C, decoder temp_u8).
2. Three new PIDs — 0x5E fuel rate L/h (u16_fiftieths,
   v0.14.3 PR feat(v0.14.3): three new decoders — u16_fiftieths, u32_be, u16_half #185), 0x5F engine runtime s (u32_be),
   0x62 fuel rate g/s (u16_half). All SAE J1979
   emissions-mandated. All four decoders already shipped in
   v0.14.3 PR feat(v0.14.3): three new decoders — u16_fiftieths, u32_be, u16_half #185.
3. Each new entry carries the
   [needs verification, N5x/E9x bench] label marker per
   the v0.14.3 N62 discipline.
4. Profile label field — [community, oil temp unverified] -> [community] once 0x5C is in (matching
   the v0.14.2 N62 PR feat(v0.14.2): n62.toml — swap local:10 oil placeholder for OBD-II 0x5C #175 pattern). The [community]
   conservative-sourcing marker stays until a real-car
   verification report lifts it.

Per-file changes

community/profiles/n52.toml (10 -> 13 params)

• Oil entry: local:10 -> obd:5C; label
  Oil temp [UNVERIFIED placeholder] -> Oil temp
• Added fuel_rate_lh (0x5E), engine_runtime (0x5F),
  fuel_rate_gs (0x62) with [needs verification, N52/E9x bench] markers
• Profile label: N52 2.5/3.0 NA I6 (MSV70/MSV80) [community, oil temp unverified] -> N52 2.5/3.0 NA I6 (MSV70/MSV80) [community]
• Header block: BSD oil-condition sensor note (N52's
  known oil-temp quirk — DME reads oil condition via BSD,
  not KWP2000; the OBD-II 0x5C swap is the surface the
  desktop app reads, but the harness-doc path reverts to
  local:10 if the DME returns an NRC for 0x5C).
  Valvetronic + oil-temp cruise band + idle voltage
  context added.

community/profiles/n54.toml (12 -> 15 params)

• Oil entry: local:10 -> obd:5C; label
  Oil temp [UNVERIFIED placeholder] -> Oil temp
• Added fuel_rate_lh (0x5E), engine_runtime (0x5F),
  fuel_rate_gs (0x62) with [needs verification, N54/E9x bench] markers
• Profile label: N54 3.0 twin-turbo I6 (MSD80/81) [community, oil temp unverified] -> N54 3.0 twin-turbo I6 (MSD80/81) [community]
• Header block: BSD note + charge-air / boost / HPFP /
  idle-voltage context (N54-specific). Fuel-rate ranges
  bumped to ~80-150 L/h and ~60-100 g/s at WOT (twin-turbo
  pulls more fuel than the NA N52 / N62 — the BSFC heuristic
  over RPM × cyl_count reflects this).

No Rust change

All four OBD-II PIDs reuse decoders that shipped in v0.14.3
PR #185 (temp_u8, u16_fiftieths, u32_be, u16_half).
Zero changes to src-tauri/**. No new crate, no new
#[tauri::command], no protocol/** change, no
commands.rs change, no frontend change.

The N52 BSD-not-supported failure mode

N52 oil condition is primarily communicated via the BSD
(Bit Serial Data) protocol from the oil condition sensor to
the DME, not over KWP2000. The OBD-II 0x5C swap is the
path the v0.14.2 + v0.14.3 + v0.14.5 N62 cycle established
and is the right surface to attempt. If the N52 DME returns
an NRC (0x11 serviceNotSupported or 0x12 subFunctionNotSupported) for 0x5C on a given firmware,
the v0.14.3 PR #187 per-PID NRC surface flags it in the UI
and the remove_profile_pid async Tauri command writes the
updated TOML behind a tauri-plugin-dialog confirmation
per the issue-#161 fix pattern. The harness doc (v0.14.5
slice 2) documents the failure-mode protocol.

Tier

A per CLAUDE.md — community data + docs. No
transport/**, no protocol/**, no commands.rs, no
src-tauri/Cargo.toml, no src/js/**, no src/css/**, no
src/index.html. Auto-merge eligible once required CI
checks pass.

Verification (pre-merge)

• python tomllib.load() on both files — 13 / 15
  params parse cleanly; all new entries have the
  [needs verification, N5x/E9x bench] label marker
• git diff --cached --stat — 2 files, 248 insertions,
  25 deletions (no phantom diff from line-ending
  normalization — CRLF on disk matches the committed
  blob, verified per the v0.14.3 slice 4 lessons' CRLF
  stat-noise trap)
• git ls-files --stage vs git ls-tree HEAD —
  staged blob SHAs differ for both modified files
  (n52.toml staged bac4004b vs head 473c239f;
  n54.toml staged bcc71748 vs head 07868a10); no
  no-op commit
• Branched off origin/main @ 8a71a99 (the v0.14.5
  slice-0 commit), NOT off the local main ref
• Author ohgeeceee@users.noreply.github.com (GH007
  bypass; content unchanged)
• git status clean post-commit (no untracked files
  in the staged diff, no other modifications)

Cross-references

• Cycle plan: docs/v0.14.5_plan.md (PR docs(v0.14.5): cycle plan + ROADMAP header + CHANGELOG entry #222, slice 0
  of v0.14.5) — the cycle name "Open & Committed" and the
  spine-of-3 shape
• Predecessors (the v0.14.2 / v0.14.3 N62 pattern this
  PR mirrors):
  • PR feat(v0.14.2): n62.toml — swap local:10 oil placeholder for OBD-II 0x5C #175 — feat(v0.14.2): n62.toml — swap local:10 oil placeholder for OBD-II 0x5C (slice 1 of v0.14.2)
  • PR feat(v0.14.3): n62.toml — re-enable 0x5E / 0x5F / 0x62 fuel-rate + runtime PIDs #186 — feat(v0.14.3): n62.toml — re-enable 0x5E / 0x5F / 0x62 fuel-rate + runtime PIDs (slice 2 of
    v0.14.3)
  • PR feat(v0.14.3): three new decoders — u16_fiftieths, u32_be, u16_half #185 — feat(v0.14.3): three new decoders — u16_fiftieths, u32_be, u16_half (slice 1 of v0.14.3,
    the decoders the four new PIDs use)
  • PR feat(v0.14.3): per-PID NRC errors + remove_profile_pid command #187 — feat(v0.14.3): per-PID NRC errors + remove_profile_pid command (the per-PID-NRC backend
    that surfaces the N52 BSD-not-supported failure mode
    in the UI)
• Harness doc (next PR, slice 2 of v0.14.5):
  docs/validation/n5x-real-car.md
• Decoder spec: docs/DECODE_FUNCTIONS.md § 3
  (temp_u8), § 10 (u16_fiftieths), § 11 (u32_be),
  § 12 (u16_half)

Diff stat

 community/profiles/n52.toml | 128 +++++++++++++++++++++++++++++++++++---
 community/profiles/n54.toml | 145 +++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 248 insertions(+), 25 deletions(-)

Author note

Commit authored with ohgeeceee@users.noreply.github.com to
bypass GH007 (private-email push block). Content unchanged.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Use PID 0x1F for engine runtime

On any SAE J1979-compliant ECU, PID 0x5F reports the vehicle's emissions-requirement category rather than engine runtime; runtime since start is PID 0x1F and is a two-byte seconds value. Because read_obd_pid strips the service and PID bytes and u32_be requires four data bytes, this gauge will produce no value for both the N52 profile here and the duplicated N54 entry. Query obd:1F with the appropriate two-byte decoder and range instead.

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[chatgpt-codex-connector]

Use PID 0x9D for mass fuel rate

On SAE J1979 ECUs, PID 0x62 is actual engine percent torque, encoded as one byte with an offset, not fuel rate in g/s. Consequently, the two-byte u16_half decoder returns no value for this new N52 gauge and the matching N54 gauge; if mass fuel rate is intended, its standard PID is 0x9D, encoded as a two-byte value scaled by 0.02 g/s rather than 0.5.

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[chatgpt-codex-connector]

Keep the oil-temperature entry marked unverified

For users selecting either newly changed N5x profile before the stated E9x bench verification has occurred, this removes the only visible warning from the oil-temperature gauge even though the adjacent comment explicitly says support for PID 0x5C is unverified and may require reverting after an NRC. The other unbenchmarked additions retain [needs verification] in their labels, and these labels propagate into gauges and exports, so the N52 and N54 oil labels should retain the same qualification until real-car support is confirmed.

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