How do you reset immobilizer on fiesta?

To reset the immobilizer on a Ford Fiesta, first ensure that you have the correct key fob and that the battery is functioning. Insert the key into the ignition and turn it to the "On" position without starting the engine, then back to "Off," repeating this step three times. After the third turn, leave the key in the "On" position and wait for the immobilizer light to stop blinking, which indicates the system has reset. Finally, try starting the engine. If issues persist, consult the vehicle's manual or a professional mechanic.