blueprint

Yes i am absolutely sure of it. I had an 02 and currently have an 03 AP1. My 08 AP2 is different in that the key itself has a chip that deactivates the immobilizer.

In the AP1 If you arm your car with the key fob the immobilizer is enabled. There is no way to deactivate the immobilizer unless you have the Fob that is programmed with it.

This has happened to me twice... Dropped remote and broke fob. Manually opened the car and tried to start her but no dice, when u stick the key in normally a green key light will illuminate indicating the immobilizer is deactivated. The AP1 key does not have a chip in it. In this event the fob did not deactivate the immobilizer so the car wont start. Another time my battery died and again stranded... The only thing that worked to start the car was to change the battery in the fob.

murdocsgarage

I'm pretty certain the AP1 key has a chip in it.

However, the whole key fob needing to unlock the car to start it is feasible. Years ago I think the same thing happened to me, but it was in a civic. And my old Mercedes did a similar thing, if the key wasn't used to unlock the car the alarm would also go off when trying to start the car.

blueprint

There is a chip in it your correct but it's not like the AP2... atleast in 06+ AP2's.

Im just recalling from my own experience since it's happened to me twice. The only way I could successfully start my car was to use the FOB. Without the FOB i could not start the car.

RMurphy

blueprint: did your vehicles have an actual alarm system though? The pattern you described matches vehicles I've seen with alarm systems. Not saying that's the only explanation, but... The S2000 didn't come with an alarm from the factory. One could be installed at a Honda dealership though.

And I'm beginning to get the feeling we aren't going to get an update from the OP who so immediately needed an answer.