Most modern car keys today contain a computer chip that is programmed so that the car and key communicate electronically, allowing the car to function. This type of key called transponder key. They are often referred to as “immobilizers” as they’re designed to make it difficult to steal a car without a key that is programmed for the specific vehicle.
A “transponder” is an electronic device that is used to transmit and receive electrical signals wirelessly. The word “transponder” originates from the terms Transmitter + Responder. Technically keys made with a programmed chip would be considered “transponders”.
These keys are part of the cars anti-theft system. The small microchip that is embedded in the plastic head of a car or motorcycle transponder key receives a signal from an antenna ring around the ignition cylinder. If the vehicle’s computer doesn’t receive the appropriate response from its transponder key it won’t operate. Most car keys produced after 1998 have transponder chips.
When you turn a transponder key in the ignition, the engine control unit of the car transmits an electronic message to the key, starting the car if it receives the appropriate message back. This means that the key needs to be cut correctly in order to turn the locks as well as accurately programmed in order to disarm the immobilizer.
If your transponder key remote (transmitter) requires batteries and they die, you can more than likely change it yourself. Transponder key batteries can be obtained at most auto part retail stores. Obviously, transponder keys that don’t require batteries a lot more convenient.
Occasionally transponder keys will have to be reprogrammed. It is possible to program some keys yourself, and you can find instructions in the owner’s manual. You’ll need to have at least two master keys in working order to program a third or fourth transponder key. If you don,t have a spare, call an experienced car locksmith and have them do it for you.
If you lose your only transponder car key, you’ll need to have your vehicle either towed to the dealership or contact a locksmith who has the equipment required to cut and program transponder keys. Calling a mobile locksmith will save you a lot of money because you can avoid a towing fee. That said, some car models have keys that require that you take them to the dealership for programming so ask the locksmith if that is the case with yours.
There are two basic kinds of transponder keys, encrypted and zero bitted. If your locksmith uses a new key along with a special tool that he connects to your cars OBD port in order to program the key, he’s adding a distinctive, encrypted key to your cars system. Encrypted keys have a random, preset encryption that must be programmed to the car. Zero bitted keys on the other hand, don’t have a preset inscription and are set up to be duplicated. In this case the locksmith will clone your transponder key by inserting it into a special tool, followed by inserting a key blank into the same tool.