@emdzej/ncsx-identity

Read VIN, FA, and ZCS from a connected BMW ECU. Picks the right identity SG per chassis using SGFAM's FA/ZCS flags — no hardcoded chassis tables, no per-generation switch statements.

Different chassis generations carry vehicle identity in different ways:

• FA-master chassis (post-E60-ish): a single token string — E89_#0306&N6SW%0354$167… — handed back verbatim by the SG. Edited by adding / removing tokens.
• ZCS-master chassis (E36 / E38 / E39 / E46 / E53): three structured fields — GM (base-model code), SA (hex-encoded bit-set indexed by <BR>ZST.*), VN (version number).

VIN comes through on both paths via a separate FGNR_LESEN job.

Usage

import {
  readVin,
  readFa,
  readZcs,
  formatFahrgestellNr,
} from "@emdzej/ncsx-identity";

const { vin } = await readVin(sgbd, ediabas);
const { fa } = await readFa(sgbd, ediabas);          // FA chassis
const { zcs } = await readZcs(sgbd, ediabas);        // ZCS chassis

// Format VIN as the 18-char FAHRGESTELL_NR the IPO expects in
// `C_FG_AUFTRAG`'s `para` — appends the BMW Mod-36 check char.
const fgnr = formatFahrgestellNr(vin);
// "WBAAA00000PM10277" → "WBAAA00000PM10277L"

sgbd is an EDIABAS module name ("C_KMB46", "D_KOMBI", …) — typically derived from SGFAM's identity row. ediabas is anything matching EdiabasLike from @emdzej/ncsx-wire — @emdzej/ediabasx-ediabas's Ediabas class satisfies it.

Picking the right identity SG

import { findIdentitySg } from "@emdzej/ncsx-chassis";  // chassis-bundle helper

const idRow = findIdentitySg(chassis);
const { vin } = await readVin(idRow.sgbd, ediabas);

findIdentitySg walks SGFAM looking for the row whose FA-master or ZCS-master flag is set. Falls back to a deterministic per-chassis-code map if SGFAM doesn't mark one.

BMW Mod-36 checksum

mod36Checksum(input) and formatFahrgestellNr(vin) are direct ports of NCSEXPER's coapiSetFgNr → CalcMod36CheckSum. The algorithm sums the input's character codes weighted by position modulo 36, mapping the remainder back to [0-9A-Z] (skipping I, O for visual disambiguation).

Worked example, unit-tested: "FPWBAAA00000PM10277" → 'L'.

Exports

export { readVin, padFgnrToVin, type VinReadResult, type PaddedVin };
export { readFa, type FaReadResult };
export { readZcs, type ZcsRead, type ZcsReadResult };
export { mod36Checksum, formatFahrgestellNr };
export type { IdentityReadResult };

Consumers

• apps/web/src/components/IdentityPanel.svelte — drives the identity card in the UI.
• apps/web/src/lib/process-ecu.ts — processWriteCoding calls formatFahrgestellNr(app.identity.vin) and seeds it as FAHRGESTELL_NR via CDHSetSystemData so SG_CODIEREN's post-write C_FG_AUFTRAG has the right 18-byte chassis number to thread into the SGBD.