My Honda Civic '04 has a stock alarm system. Whenever I press the key fob to unlock/lock the doors, I hear a chirp sounds. However, lately I haven't been able to hear the chirp sound even though my car still locks/unlocks.

Any inputs?

 

I've never heard an OEM alarm "chirp" when it's activated - only the horn "honking" for a split second.

Are you certain that you don't have an aftermarket alarm system? Or were you referring to the noise the horn is supposed to make?

 

I've had this same problem. If you're just talking about the short "honk" after you lock the car, try replacing the battery in the remote. I resolved this same problem not too long ago.