Mercedes C-Class 2nd (W203) (2001–2007) — Key Programming Reference
- Difficulty
- hard
- Lishi / lockout
- HU64
Key fobs & transponder keys (2 variants)
| Key | Years | FCC ID | P/N | Chip | Freq | Battery | Blade |
|---|---|---|---|---|---|---|---|
| 315 MHz · IYZ3312 | 2001-2006 (early-to-mid W203 run) | IYZ3312 | 5WK47283 | Mercedes FBS3 NEC/BGA (IR-read at EIS) | 315 MHz | CR2025 | HU64 |
| 315 MHz · IYZ3317 | 2006-2007 (late W203 facelift run) | IYZ3317 | KR55WK49031 | Mercedes FBS3 NEC/BGA (IR-read at EIS) | 315 MHz | CR2025 | HU64 |
Programming procedures
What the job needs
- Add a key: 1 existing working key required.
- All keys lost: no existing working key needed.
- PIN / security code: No PIN — IR + tokens.
- Online / server access: required — Cloud token req'd.
- On-board (no tool) sequence: not available — 2001-2007 W203 has no DIY onboard programming. Mercedes XENTRY / DAS dealer relearn requires SCN coding certificate (still available for classic chassis at MB classic-car service centers). Aftermarket Add Key requires VVDI MB Tool + W203 IR adapter + tokens OR Abrites AVDI Mercedes (EU-preferred for pre-2003).
- On site: engine off · 12V+ + charger · Clear EIS + DAS DTCs.
- Bring: Photo ID + vehicle registration. Title strongly recommended for AKL on classic-era Mercedes (W203 is 25+ years old — title chain verification critical).
Tool coverage
Documented for this case on: Autel IM608 Pro II · Autel IM508S · Autel KM100 · Xhorse Key Tool Plus · Xhorse Key Tool Max Pro · Lonsdor K518 Pro / K519 · OBDSTAR X300 DP Plus · AutoProPad G2/G3 · Advanced Diagnostics Smart Pro · Launch X431 IMMO Elite / IMMO Plus. Step-by-step menu paths for each tool are in the app.
Notes & cautions
- This chassis (W203 C-Class, 2001-2007) is Mercedes FBS2 NEC-IR EIS era — the successor to W203 FBS2 + predecessor to W204 FBS3. FBS2 era uses IR (infrared) read of EIS password via dashboard IR port, not OBD-only like FBS3. Two FBS2 sub-eras within W203: 2001-2004 early (NEC EIS only), 2005-2007 facelift (added security counter revisions). Verify trim + production date — wrong FCC key will not pair.
- FBS2 IR EIS on this variant (W203 C-Class) requires Xhorse VVDI MB Tool + W203 IR adapter cable (W203-specific SKU) OR Abrites AVDI Mercedes (EU-locksmith standard for pre-2003 Mercedes — best IR success rate). Autel IM608 + IMKPA covers W203 FBS2 but IR read is the bottleneck — IM608 password calc itself works once IR data is read. CGDI MB has FBS2 coverage from 2004+ NEC variants (W203 era and later — but W203-specific behavior covered), not pure FBS2 W203.
- W203 AKL is OBD-or-IR — bench EIS removal needed if IR port damaged. IR read success on W203 is good (~80% per locksmith reports, similar to W203). Verify IR port functional before quoting OBD/IR vs bench pricing. AMG C32 / C55 W203 variants share standard EIS architecture — no AMG-specific quirk on FBS2 era.
- AKL on this chassis erases all previously paired FBS2 IR keys. Bring minimum 2 new Mercedes FBS2 NEC IR keys matching trim. Wrong chip family (e.g., FBS3 NEC EIS keys from W203/W204 era) will not work — verify chip generation before ordering.
- W203 AKL is OBD-or-IR friendly when IR port is intact (~80% IR read success). Damaged IR port = bench EIS EEPROM read via Autel XP400 PRO or Xhorse VVDI Prog. Bench job adds ~1 hour vs IR. Verify IR port functional before quoting bench-vs-IR pricing.
- AKL erases EIS-paired remotes. Recovered old keys will not authenticate — customer must be informed. Verify trim before scheduling: C230 / C240 / C320 / C350 / C32 AMG / C55 AMG all share W203 EIS architecture. Older W203 (2001-2007) — title chain verification recommended given vehicle age.
Lockout
Door pick / decode: Lishi HU64 (CW).
42 verified sources · Last verified: 2026-08-09
Open full case in KeyAssist →Step-by-step tool menu paths, verified source links and video guides for this case are in the KeyAssist app — free to start, works offline.