Hello. My car is Honda Civic 2004 and I was being curious about this little device near my right headlight and battery. The one with blue wire. Does anyone knows what it is? I am just wondering if it is important or maybe i pulled it from nearby parts. Thank you.

 

It's a service check connector. It should be there and capped off like that. I can't remember exactly what that is but I think its a tachometer signal. At least the NEP signal is usually a blue wire.

 

It IS in fact a tach signal "test port"... referred to as the NEP signal by the factory Honda FSM or EDM.

 

Thanks Buddy. At least now I know my car was just fine.

 

Thank you Bro. Now I know.