Flashing Green Key

In the upper-left hand quadrant of my instrument cluster, there's a green key that flashes. It flashes when I shut off the car and get out. The VERY NEXT time I start the Civic, the green key flashes. Owners manual says that this indicates the fuel system shut-down, which will require the keys specifically for the Civic (knowing that they have a little transponder in them to activate the fuel system).

When that green key flashes every other start-cycle, the car still starts, still runs, doesn't buck nor jump, still operates normally, but that green key flashes. Any idea what this signifies, and what home-test may be done to check the challenge?

The flashing is normal at start up and after turning off car.

If you got a faster flash when attempting to start it would indicate the immobilizer system did not like something.

Yes, I noticed it at both start and shut-off. My concern is what it might mean that it would continue to flash after the car has started and the car is moving, taking me to my next destination? Does it mean that injection system is not operating properly? Is a solenoid bad?

It is working just fine. Those are all normal operation. If the immoilizer had seen a problem the car would not start and the blinking would be faster.