What does the key light mean on a Honda Civic?

The key light on a Honda Civic means that the immobilizer system is activated. The immobilizer system is an anti-theft device that prevents the car from being started without the correct key. If the key light is illuminated, it means that the immobilizer system has detected a problem with the key. Try turning the engine off and back on. If the light is still lit, try using a different key. If this does not work, it may be necessary to have the vehicle towed to a Honda dealership or authorized repair center.