keyless entry/smart key/remote fob failure trouble shooting

Upon picking up my 2004 from my trusted mechanic who changed the a/c evaporator coil, I discovered that somehow I have lost all functions of the remote fob, including keyless entry/starting, door lock and panic button functions. Could there be some simple connection, programming issue which could restore these functions which would not include another disassembly of the dashboard, which appeared to be an unbelievable job when I saw it all apart. Any thoughts (I HAVE replaced the fob battery).

 

Doug: Thanks for the reminder of the "key" button under the steering column. In 12+ years I have never used that button. Now the keyless entry/keyless start works with both of my original fobs, but none of the buttons on the fob work to lock/unlock or sound horn/blink lights with the panic button on either fob. I just now replaced the fob battery with one from another new package Any thoughts on that issue?