Toyota Avalon 2nd (XX20) (2000–2004) — Key Programming Reference

- Difficulty
- easy
- Lishi / lockout
- TOY43AT
- Platform
- MCX20
Key fobs & transponder keys (2 variants)
| Key | Years | FCC ID | P/N | Chip | Freq | Battery | Blade |
|---|---|---|---|---|---|---|---|
| 89785-41020 · 4C | 2000–2004 NA — required for engine start (immobilizer always-on) | n/a | 89785-41020 | Texas Instruments 4C (fixed-code, non-crypto) | n/a | n/a | TOY43 |
| HYQ12BAN · 314.35 MHz | 2000–2004 NA — factory keyless entry option (all trims) | HYQ12BAN | 89742-AC050 | none | 314.35 MHz | CR2016 | n/a |
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: required — NASTF + Lonsdor + dealer.
- Online / server access: not required (offline programming).
- On-board (no tool) sequence: not available — Toyota Avalon Texas 4C requires professional OBD tool — no self-programming procedure.
- 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 Toyota Avalon uses Texas 4C Crypto-1 (Toyota 1998-2002 era, 2000-2004). Older pre-OBD2 / early OBD2 chip — Autel IM608 + IMKPA Toyota, Lonsdor K518 USA + Toyota adapter, Xhorse VVDI Key Tool Plus cover. Some chassis need K-line OBD or bench EEPROM (TIS / Techstream dealer fallback).
- Smart proximity or remote head key: ensure existing key fob battery is functional before starting.
- Verify chip before booking (this chassis facelift): Honda spans ID13 (pre-2003) → ID46 V chip (2003-2014) → ID47 (2014-2017) → 4A AES (2018+); Toyota spans 4C (1998-2002) → 4D67 dot (2003-2007) → G chip (2008-2013) → H 8A (2014+). Some facelift mid-MY chassis swap chip — confirm transponder ID from a working key with Lonsdor K518 reader before quoting.
- Tool kit context: Autel IMKPA + Honda/Toyota cloud token (~$5-15/session) and Lonsdor LKE Smart Key Emulator for K518 simulated-key flow are the dominant accessories. Xhorse KH100 + Honda/Toyota module confirmed. APB112 simulator, G-Box bench EEPROM NOT typically needed. XP400 PRO only for BCM/IMMO bench fallback.
- All existing keys erased. Bring ALL replacement keys before starting — minimum 2.
- No manual AKL for Toyota Avalon Texas 4C — professional tool mandatory.
- AKL for Texas 4C via OBD; older chassis sometimes need bench EEPROM dump (Honda ID13 / Toyota 4C).
- Keep all existing/lost key fobs at least 10 metres from vehicle during AKL.
- AKL accessory needs: Autel IMKPA + Honda/Toyota AES token for cloud calc on newest VINs, Lonsdor LKE Smart Key Emulator for K518 simulated-key AKL path, Xhorse KH100. APB112 NOT mandatory. G-Box bench EEPROM NOT used. XP400 PRO only if BCM/IMMO EEPROM corrupted (rare).
Lockout
Door pick / decode: Lishi TOY43AT (CW).
56 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.