Audi A4 2nd (B6) (2001–2005) — Key Programming Reference
- Difficulty
- medium
- Lishi / lockout
- HU66
Key fobs & transponder keys (2 variants)
| Key | Years | FCC ID | P/N | Chip | Freq | Battery | Blade |
|---|---|---|---|---|---|---|---|
| 315 MHz · MYT8Z0837231 | 2002–2005 NA (FCC MYT8Z0837231 granted 2002-09-24) | MYT8Z0837231 | 4D0837231M | Megamos Crypto ID48 | 315 MHz | CR2032 | HU66 |
| 433.92 MHz · 8Z0837231D | 2001–2005 (A4 B6 RoW; FAW-Audi China-built 2000–2006; AU/GCC export) | n/a | 8Z0837231D | Megamos Crypto ID48 | 433.92 MHz | CR2032 | HU66 |
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: NASTF + VVDI Prog + dealer.
- Online / server access: not required (offline programming).
- On-board (no tool) sequence: not available — Audi A4 VAG ID48 IMMO 1-3 requires professional OBD tool — no self-programming.
- On site: engine off · Maintain 12V+ · Clear IMMO DTCs.
- Bring: Photo ID + vehicle registration. VIN cross-check before start.
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 Audi A4 uses Megamos ID48 Crypto (VAG IMMO 1-3, 2001-2005). ID48 covered by Xhorse VVDI Prog + Megamos module, Autel IM608 Pro II + IMKPA VAG, AD Smart Pro ADS185 VAG. CS component protection via OBD; bench EEPROM (Xhorse VVDI Prog) fallback for damaged IMMO box.
- Smart proximity or remote head key: ensure existing key fob battery is functional before starting.
- Verify chip before booking (this chassis facelift): VAG IMMO generations span ID48 Megamos (pre-2008) → HITAG-2 PCF7945AC (2008-2014) → HITAG-PRO ID88 MQB (2014-2018) → Megamos Crypto ID48 / 8E (2018+). Mid-cycle facelifts on Golf 7, Passat, Tiguan, A3, Cayenne 92A swap chip mid-MY — confirm transponder ID from a working key with VVDI reader before quoting.
- Tool kit context: Xhorse VVDI MQB Plus token ($25-40/car) for MQB ID88 chassis; VVDI Key Tool Plus + VVDI Prog dominant aftermarket. Autel IMKPA VAG module + cloud token also supported. AVDI niche tool for Porsche/Lamborghini VAG. APB112 simulator, G-Box bench NOT used. XP400 PRO only for IMMO box bench fallback.
- All existing keys erased. Bring ALL replacement keys before starting — minimum 2.
- No manual AKL for Audi A4 VAG ID48 IMMO 1-3 — professional tool mandatory.
- AKL for VAG ID48 IMMO 1-3 needs CS component protection + token (VVDI MQB Plus / IMKPA cloud) + dealer PIN on newest MEB chassis.
- Keep all existing/lost key fobs at least 10 metres from vehicle during AKL.
- AKL accessory needs: Xhorse VVDI MQB Plus token + VVDI Key Tool Plus for MQB, AVDI MEB module for ID.4/e-tron family, Autel IMKPA VAG cloud token. APB112 NOT mandatory. G-Box bench EEPROM NOT used. XP400 PRO only if IMMO box EEPROM corrupted (rare).
Lockout
Door pick / decode: Lishi HU66 (CW).
25 verified sources · Last verified: 2026-08-10
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.