For some reason or another my Wife's Remote Key Fob just stopped working. She has to stick the Key in the door to unlock the Vehicle. We changed the battery with no luck. Now the one I have will unlock the vehicle but to lock it, it used to beep the horn, but now it doesnt. Any ideas/suggestions? It is an 05 LE with Tech Pkg. tks Mikey

Look at attachment (from the owner's manual!)