Automotive Locksmith Glossary

110 key-programming terms explained in plain language: transponder chips, immobilizer systems, remotes, Lishi picking and programming equipment.

Programming jobs & concepts

AKL: All Keys Lost — programming a new key when the owner has NO working key. Harder than Add Key; often needs OBD or EEPROM access.
Add Key: Programming an additional key when the owner still has at least one working key. The easiest programming job.
OBP: On-Board Programming — a dealer-style key-learning sequence done with existing keys / ignition cycles, no diagnostic tool.
EEPROM: A memory chip inside a module (immobilizer/BCM). Reading its dump lets a locksmith recover the PIN or program a key on the bench.
Cloning: Copying an existing transponder onto a blank chip so the car sees an identical key. Works only on cloneable (non-rolling) chips.
Virgin key: A blank, never-programmed key/fob ready to be learned to a car.
Pre-coded key: A key already cut and/or partly coded to a specific VIN by a supplier, so the locksmith only finishes programming.
Dealer key: A key supplied/programmed by the franchise dealer, usually at higher cost than an aftermarket locksmith key.
Learning mode: The temporary state where a car will accept (learn) a new key — entered via tool, ignition sequence, or PIN.
Sync: Re-pairing a remote so its rolling-code counter matches the car again after it drifted out of range.
Emergency start: Backup way to start a smart-key car with a dead fob battery — usually hold the fob against a marked spot (start button, column, cupholder).

Transponder chips

Transponder: The passive electronic chip in the key head. The immobilizer energises it and reads its ID before allowing start. No battery needed.
Crypto chip: A transponder that answers a challenge with an encrypted response (rolling), so it can't be simply copied. Opposite of a fixed-code chip.
Fixed-code chip: An older transponder that always replies with the same ID — easy to clone. (e.g. 4C, 4D fixed.)
ID46: Very common Philips/NXP crypto transponder (PCF7936/7941). Honda, GM, Chrysler, Hyundai/Kia and many more.
PCF7936: The chip part number behind "ID46". Same thing — different naming.
PCF7945 / PCF7953: NXP smart-key transponder ICs (HITAG2 / HITAG Pro families) used in many proximity fobs.
ID47: HITAG3 / PCF7938 crypto chip — Honda, Hyundai/Kia 2014+. Higher security than ID46.
ID48: Megamos crypto transponder — VW/Audi/Seat/Skoda and others up to ~2014. PIN often needed.
ID49: HITAG Pro / HITAG-AES chip — newer Ford, Mazda, VW Group. Harder to clone.
4A: HITAG-AES transponder (a.k.a. ID4A/8A) — Honda/Acura, Toyota, Hyundai/Kia smart keys 2015+.
4C: Old Texas fixed-code transponder (Toyota, Ford 1990s-2000s). Cloneable.
4D: Texas Crypto transponder family (4D60/4D63/4D70/4D72…). Toyota, Ford, Mazda, Mitsubishi.
4D63: Texas 4D 80-bit transponder — Ford and Mazda (e.g. 6-cut H-series). Needs an 80-bit-capable tool.
DST40: Texas Digital Signature Transponder, 40-bit — older Toyota/Lexus "dot" keys.
DST80: Texas 80-bit DST — Toyota/Lexus mid-era. Requires a specific Autel/Xhorse 80-bit procedure.
DST-AES: Texas AES (8A) transponder — newest Toyota/Lexus "G/H" generation security.
G chip: Toyota high-security transponder (~2010+) marked "G". Cannot be cloned — must be OBD-programmed.
H chip: Toyota AES transponder (~2014+), marked "H". Even tighter security than the G chip.
Megamos: Megamos transponder family (ID13/ID48). VW Group and others; ID48 versions need a PIN.
HITAG2: Widely used Philips/NXP crypto family (~2001+). VW, Audi, Porsche, BMW, many remotes.
HITAG3: Newer NXP family (ID47) — higher security than HITAG2.
HITAG Pro: NXP HITAG Pro (ID49) — used in newer Ford and VW Group; harder to clone.
HITAG-AES: AES-encrypted NXP transponder (4A) used in modern smart keys.
Temic: Older transponder brand (8C/11/12) found in early VAG, Mercedes, and others.
Philips Crypto: Generic name for NXP/Philips encrypted transponders (ID33/40/41/42/44/45/46).

Immobilizer / ECU systems by brand

IMMO: Immobilizer — the anti-theft system that blocks fuel/start unless the correct chip is present.
ECU: Engine Control Unit — the computer that runs the engine; talks to the immobilizer to authorise start.
BCM: Body Control Module — runs locks, lights, and often the immobilizer/key functions on modern cars.
PCM: Powertrain Control Module — the engine+transmission computer (Ford/GM term for the ECU).
CAS: Car Access System — BMW immobiliser/key module (CAS1-CAS4) ~2002-2015.
FEM / BDC: BMW Front Electronic Module / Body Domain Controller — key+access module from ~2013 onward.
EWS: Older BMW immobiliser (pre-CAS, ~1995-2006).
EIS / EZS: Mercedes Electronic Ignition Switch — the steering-lock/start module that pairs to keys.
BSI: Built-in Systems Interface — PSA (Peugeot/Citroën) central body+immobiliser computer.
CEM: Central Electronic Module — Volvo body/immobiliser computer.
SKIM / SKREEM: Chrysler/Jeep/Dodge immobiliser modules (Sentry Key). Need a PIN to add keys.
PATS: Passive Anti-Theft System — Ford's immobiliser. Often needs an "incode/outcode" or PIN.
PASSlock: GM anti-theft using a resistor in the lock, not a transponder. Has a 30-minute relearn.
VATS: Vehicle Anti-Theft System — early GM resistor-pellet key system.
WFS: Wegfahrsperre — VW Group's immobiliser (IMMO 1-5).
KESSY: VW Group Keyless Entry Start & exit System — proximity smart-key system.

Remotes & smart keys

RKE: Remote Keyless Entry — a plain remote (lock/unlock buttons), may or may not contain a transponder.
PEPS: Passive Entry Passive Start — you keep the fob in your pocket; the car unlocks on touch and starts on a button.
Smart key: A proximity fob (PEPS). Talks to the car by LF/RF; no metal key needed to start.
Prox: Short for proximity (smart) key.
Push-to-start: A start button instead of a turn ignition — paired with a smart key system.
Flip key: A key whose blade folds into the fob at the press of a button (switchblade).
RHK: Remote Head Key — a one-piece key where the transponder blade and the remote buttons share one housing.
Valet key: A limited key (often no remote/trunk access) given to parking attendants.
FOB: The plastic key housing holding the transponder, remote buttons, and (for smart keys) battery + emergency blade.
Emergency blade: The small metal key hidden inside a smart fob, used to open the door if the battery/electronics fail.

Identifiers & codes

FCC ID: US Federal Communications Commission ID printed on the fob — identifies the exact remote/transmitter.
IC: Industry Canada ID — the Canadian equivalent of the FCC ID, often printed beside it.
PN: Part Number — the manufacturer/aftermarket SKU for the key blade, fob, or shell.
Part Number: Same as PN — the catalog number that pins down the exact key/fob/shell to order.
Blade code: The key-blank designation (Ilco/Silca/JMA), e.g. HU66, HON66, TOY43 — identifies the keyway/profile.
Key code: The cut combination of a key, expressed as depths/spaces. Lets a machine cut a key without the original.
Bitting: The actual depth values of each cut on the blade (e.g. 1-3-5-2…).
Cut-to-code: Cutting a key from its key code (looked up by VIN/lock) instead of by duplicating an existing key.
VIN: Vehicle Identification Number — the 17-char car ID. Used to look up key codes, PINs, and the right key.
NHTSA: US road-safety agency; its VIN decoder confirms make/model/year/trim.

Radio / frequency

Frequency: The remote's radio frequency. 315 MHz (US/Asia), 433/434 MHz (EU/most world), 868/902 MHz (some). Must match the car.
LF: Low Frequency (125 kHz) — used to power and wake the transponder/smart key near the car.
RF: Radio Frequency — the UHF band (315/433/868 MHz) the remote uses to send button/lock signals.
UWB: Ultra-Wideband — precise short-range radio in the newest phone-as-key and anti-relay smart fobs.
Rolling code: A remote code that changes every press (encrypted counter) so a captured signal can't be replayed.
Fixed code: An old remote code that never changes — easy to copy. Replaced by rolling code for security.

Lock mechanics & picking

Lishi: Brand of 2-in-1 pick+decode tools, one per keyway (HU66, HON66…). Picks the lock and reads the cuts to make a key.
2-in-1: A Lishi tool that both picks the lock open AND decodes the wafer depths at the same time.
Decode: Reading the lock's cut depths (after picking) so you can cut a working key without the original.
Wafer: The flat spring-loaded tumblers inside most car locks (instead of pins). Lishi tools read/move these.
Pin tumbler: A lock that uses round pins instead of wafers — common on older/European locks.
Disc detainer: A high-security lock using rotating discs (e.g. some Mercedes/Volvo). Needs a special tool.
Sidebar: A locking bar that must align before the plug turns — adds security on GM and others.
Keyway: The shaped slot a key enters. Its profile (HU66, HON66…) decides which blank/Lishi fits.
Sidewinder: A "laser-cut" key with a wavy milled track down the middle of the blade (high security).
Laser cut: Same as sidewinder — a track milled into the blade face rather than edge cuts.
Edge cut: A traditional key with cuts on the edge of the blade (the older, simpler style).
Plug: The rotating core of the lock cylinder that the key turns.
Cylinder: The complete lock barrel (door/ignition/trunk) the key operates.
Tension: The light turning pressure held on the lock while picking, so set wafers stay set.
False set: A misleading click that feels like the lock opened but didn't — common on scored/security wafers.
Blank: An uncut key of the correct keyway, ready to be cut to code or by duplication.
CW: Clockwise — the turning direction of the lock (e.g. to unlock).
CCW: Counter-clockwise lock rotation.
Blade: The metal cut part of the key that enters the lock (separate from the transponder/remote).

Equipment & tools

OBD: On-Board Diagnostics — the 16-pin port (under the dash) used to talk to the car's computers and program keys.
OBD2: The standard OBD-II diagnostic port present on all cars since ~1996 (US) / 2001 (EU).
Autel: Maker of IM508/IM608 key-programming and diagnostic tools.
Xhorse: Maker of VVDI key tools, the Dolphin/Condor cutting machines, and universal remotes.
VVDI: Xhorse's key-programming product line (VVDI2, Key Tool Plus/Max).
Lonsdor: Maker of the K518 key programmer, strong on Toyota/Lexus AKL.
OBDSTAR: Key-programming tool brand (X300 series).
Smart Pro: Advanced Diagnostics key programmer (uses paid software tokens per car family).
Dolphin: Xhorse portable automatic key-cutting machine (XP-005).
Condor: Xhorse automatic key-cutting machine (XC-Mini / Condor) for edge and laser keys.
PIN Code: Secret code some cars need before adding a key — read by tool, calculated from VIN, or pulled from EEPROM.
Incode / Outcode: Ford PATS challenge/response: the tool shows an outcode, a service returns the matching incode to enter key-learn.
Token: A paid software credit some tools (Smart Pro, certain Autel functions) consume per programming job.

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