So here's the deal, i just bought a 2001 honda civic, and the keyless entry system doesnt work, so ive been using my key, i just tried to replace the battery and went to a friend of mind who referred me here, does anyone have any suggestions? and is this system built in?

 

I know exactly what you're talking about. There is a button on your remote for it but it's NOT built in. I had to get an aftermarket alarm put in and they added the keyless entry as an option when it was installed w/a whole different new remote. I noticed the Honda dealer gives you that remote but it really doesn't even offer a real functioning alarm or the keyless entry. Go for an aftermarket alarm system and tell them you want the keyless entry added. That's what I did.

 

It could be a faulty receiver unit. Did the previous owner mention whether or not it used to work?