Definitions & Descriptions
Transponder / Transponder Chip
Located in the plastic head of a key. Not visible when looking at key. Method of theft deterrent. Sends a code to the vehicle’s Immobilizer – if the key is programmed the car starts. If it is not programmed to the vehicle, the car will not start. Comes in different encryption types – including fixed (meaning the code never changes) and crypto (meaning the code rolls and changes every time it is used based on a logarithm). Each vehicle Make has specific chips with different encryptions that they use – this means that Honda chips don’t work for Fords, Chrysler chips don’t work with Nissans, etc.
Key containing a transponder chip in the head of it. Must be cut and programmed to a vehicle before it will start the car. The key does not have a battery in it.
Remote / RKE / FOB
RKE stands for remote keyless entry – it is an electronic unit that hangs on a keychain with buttons for lock, unlock, panic and sometimes trunk, remote start, sliding doors, etc. Must be programmed to a vehicle before it will perform its functions of locking, unlocking and arming / disarming a vehicle. Separate unit from the key. Even if a remote has a remote start function, a car cannot be driven without the key. Cannot function without a battery with adequate voltage.
Remote Head Key
Car key that has the remote built onto the head of the key. There is still a transponder chip present, but in many cases that is programmed separately from the remote portion. This design has a common flaw where the key blade breaks away from the plastic head. A case replacement is possible when a break such as this occurs. Contains a battery for the remote to function.
Smart / Proximity / Intelligent Key
Car key that can usually be kept in pocket or purse and will start the car with the push of a button on the dashboard of the car. There is a delicate copper coil inside that transmits the transponder information and the remote information when this key is within a certain proximity of the vehicle. Relies on a battery with adequate voltage to perform. Always contains an Emergency Key which slides out and can be used to enter vehicle when battery in smart key gets too low to function. There is always a place in the vehicle where the key can be placed in order to start the car when the battery in the smart key is dead – it may be a special slot or it may be up against the start button on the dash (this varies by vehicle Model).
Key tucked inside smart keys that can open the car door / glove box but cannot start the vehicle (unless the vehicle has a twist-knob type ignition).
FOBIK stands for Fob Integrated Key. Fob is just another word for Remote. FOBIKs have a square shape at the tip where they plug into the dash of the vehicle and turn like a key would in the ignition. They have the same components as a remote head key, but also have an emergency door key tucked into them like a smart key does.
Remote head key that has a key blade that rotates and locks out for use and tucks away when not needed.
High Security Key
Key blade that is considered a milled cut. There is material left underneath the cut (sometimes called the webbing). Sometimes the cut is in the center of the key blade and sometimes it is on one or both sides of the key.
Keys that have a key blade that is roughly hexagonal shaped. They are cut at odd angles and they are very difficult to duplicate. Requires a special machine and/or adapter to cut. Jaguars and a few Fords have this type of key.
Computer module in a car that is responsible for storing key information in its memory slots. Immobilizers receive a coded signal from the transponder chip in a key and determine whether or not to allow the vehicle the crank based on the code. If the code from the key matches the code in one of its memory slots, the vehicle will crank. The transponder chip in the key is only required to give a key once – when the vehicle is being cranked; after the vehicle is running, the key will not be checked again by the immobilizer until the next time the vehicle is turned on.
An early version of antitheft technology on car keys which predates transponder chips. VATS stands for Vehicle Anti-Theft System. Used on keys for most GM models from 1984 until it was phased out completely in 2004. VATS keys use a resistor chip which is actually visible on the key blade in order to complete the circuit on the ignition so the vehicle will start. Resistance is measured in Ohms. There are 15 different VATS resistor possibilities per key. It is crucial to read the Ohm value of the existing key (if there is one) or get the required value by VIN from GM, otherwise a key that is cut properly will still not crank the vehicle. The VATS resistor chip required by a vehicle will not change if the ignition is changed.