Lock problem

For a while now neither of the remote keyfobs will unlock (or lock, for that matter) our 5. Initially I changed the fob batteries but that did not fix the problem. We've just been unlocking the driver's side with the key and hitting the button inside to open the rest of the locks, but today even the button wouldn't unlock the doors, although it would lock them. Later in the day the button started working again but the keyfobs still do not. The problem was the same with both driver and passenger lock switches.

I'm thinking this is a control unit problem of some kind. Could anyone enlighten me as to what might be the source of the issue?

Thanks kindly!

I wish I could help. The only problem my keyfob had was not sending a strong enough signal. I added tension to the keyfob's battery contacts and it has been working good so far.