Immobiliser & ECU Key Programming - Auto Locksmith Services We can quickly and affordably replace and program any car key for any car ... talks to your cars ECU, and if the key fob is damaged or broken, the car won't start. microchip that contains a serial number that the car manufacturer's key programmer has made unique to that key. When inserted into the ignition, the key transmits an electronic request to the engine control units (ECU) and the immobiliser box, which then allow the car to start.An immobiliser or immobilizer is an electronic security device fitted to an automobile that prevents the engine from running unless the correct transponder car key (or other token) is present. This prevents the car from being "hot wired" after entry has been achieved ... It would be faster to program a new key to the vehicle than to try to clone the