A transponder key blank, which has not been programmed, can crank a car. It can take more than 30 minutes for the car key transponder to align itself with the system of the car, as the electronics within the car reset. Transponder car keys are available for many different cars, but are more common in high-end models.
The way transponder key programming works involves a microchip that resides in the top of the key. This microchip has a serial number, which a transponder key programmer has made unique to that key. The electronic/engine control units (ECU) will send a request to the vehicle for it to validate the serial number. If the car doesn’t recognize any serial number within its set of confirmed and correct numbers, the car will not start.
When buying a vehicle that includes transponder keys, it’s a good idea to have at least two keys. Sometimes keys are lost, so having a second valid, programmed transponder key is important. If replacement transponder keys are needed, they can usually be made by a vehicle dealer or locksmith. It may be possible for a driver to program his or her own blank keys, but the process can vary by car.