Cadillac CT4 1st generation (2020–2025) — Key Programming Reference
- Difficulty
- easy
- Lishi / lockout
- HU100
Key fobs & transponder keys (1 variant)
| Key | Years | FCC ID | P/N | Chip | Freq | Battery | Blade |
|---|---|---|---|---|---|---|---|
| 434 MHz · YGOG20TB1 | 2020-2025 NA all trims (incl. CT4-V Blackwing) | YGOG20TB1 | 13541988 | NXP HITAG-PRO ID49 (128-bit) | 434 MHz | CR2450 | HU100 |
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 VSP SAC (24-digit).
- Online / server access: required — Tool cloud login req'd.
- On-board (no tool) sequence: not available — 2020-2025 Cadillac CT4 has NO onboard programming procedure. Add Key with two existing recognized keys is dealer-side only (GM Techline SPS2 / MDI 2 / Tech 2 Win) — the "10-key OBD self-program" pre-2017 GM method does NOT work on Global B. All aftermarket paths require professional tool + NASTF SAC code.
- On site: engine off · Maintain 13.5V+ · Clear IMMO + BCM DTCs.
- Bring: Photo ID + vehicle registration. VIN match across PIN request, registration, and tool scan. NASTF locksmiths log VIN + reason for security access — keep records 7 years.
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 (CT4 2020-2025, Alpha 2 platform) uses GM Global B (SGM) architecture with CAN FD bus — REQUIRES the Autel CAN FD adapter, OBDSTAR CAN FD adapter, or built-in CAN FD on Lonsdor K518 Pro USA. Standard CAN OBD adapters (pre-2020 GM cable) WILL NOT communicate. Verify trim + year before quoting: a 2019 ATS owner can mistake their car for a CT4 — entirely different procedure.
- NASTF VSP credential + 24-digit security access code MANDATORY for all aftermarket programmers (Autel, OBDSTAR, AutoProPad, Lonsdor, Xhorse). GM banned 3rd-party direct server access in 2021 — code must be pulled via NASTF SDRM or calculated by an authorized service. No PIN = job cannot start.
- CT4-V Blackwing trim on this variant shares the same HITAG-PRO ID49 key system as base CT4 — no separate procedure. Red-accent fob is cosmetic; PN 13541988 / 13538860 / 13536990 all programmatically identical. IM608 Pro II XP400 PRO bench programmer (bundled with the kit) is NOT used on GM Global B Add Key — OBD-only path on this chassis.
- ALL existing keys will be erased when AKL completes on this chassis. Bring minimum 2 new blanks before starting — re-programming a single key after AKL leaves vehicle in 1-key state, which is a customer service failure.
- GM Global B AKL on this variant (CT4 2020-2025) requires the SAME NASTF VSP 24-digit SAC as Add Key — locksmiths cannot do AKL without VSP credentials. No PIN bypass exists on Autel/AutoProPad. OBDSTAR attempts bypass but success not guaranteed. Verify trim is non-V at quote time — CT4-V Blackwing premium pricing applies even though procedure is identical.
- AKL programming initiates a 12-minute door-cycle timer (Autel) or 10-minute equivalent (other tools). Driver door must be opened and closed every 3-4 seconds throughout. Failure to comply locks out BCM — wait 30 min + power cycle before retry.
Lockout
Door pick / decode: Lishi HU100 (CCW).
18 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.