If it's only the driver side door, it's most likely a wiring connection within the door. If NONE of the doors are opening with your fob, you'll just have to change the button battery inside of the fob.
what is the replacement battery for a 2003 Honda accord key fob
You do not have to reset the key fob when changing the battery.
I would have to recommend that you take it to the dealer for proper programming.However, I am sure that if you search on-line, there will be a number of companies who specialise in this. They'll probably need details that only the dealer can supply.The dealer will probably need to plug in your crv to a computer to interrogate the security ECU. Once they have the code, they can reprogram the fob. It should cost a lot less than the price of a replacement fob.Maybe you should act all surprised that the 'second' fob does not work and tell them you tried a new battery. If you act innocent enough, they may do it as a courtesy. It's amazing what politeness can achieve. Seriously.
Open the key fob and remove the battery which has a # on it, and then buy a duplicate.
with mvp pro programmer
please help remote fob has new battery but still will not lock or unclock my 2000 hrv
cr1616
Panasonic CR1618
The key fob battery for a Honda vehicle is changed by removing the retaining screws and gently popping the rear cover off. The battery can then be pushed out of its holder and a new one installed.
CR1616 - 3v battery
Go to the dealer, or you may be buying another key soon.