Fusion101

It's a high pitch sound almost like a camera flash makes. Anyways, it happens about twice on starting the engine. Anyone know what this is? Possibly the high intensity discharge caps are charging????

JL9000

I think it has something to do with heating up the cat faster.

sylvir2k

air pump. Helps emissions at cold start up.

RazorV3

is the s2000 the only honda to feature an auxiliary air pump? i can't think of any others, maybe the nsx *might* have one.

Casas

I have been told that it has to do with the EPS(electronic power steering), not 100% sure though.

Nobody

Does it come on about a second after the car is cranked? I'm getting a weird sound - sounds almost like a starter gear grinding - that only happens when it's cold.

jguerdat

The air pump will come on when cold and will operate in spurts or continuously for up to one minute at which time it is deactivated. Cold start emissions - add air to the exhaust stream to help burn unburned hydrocarbons...