The keyless remote on my '08 GXP sometimes works normally and sometimes not. One FOB works better than the other--better range--but even the better one sometimes will not lock the doors. Persistent pressing the lock button will eventually lock the doors--sometimes. When it won't lock, sometimes you can hear a click inside the car as though a relay is operating, but the doors don't lock. My wife says when this happens, the lock switch on the driver's armrest does not work either, which leads me to believe the problem is in-car wiring.

Unlock works more reliably, but not always. The trunk release always works. Remote start works if the doors lock.

Any ideas?