Security light never turns off

Hello: My car has the security light on the dash. It never goes off.. The car starts and runs fine, but the key fob will not lock or unlock the doors. I can use the "round"key in the doors to lock/unlock on both front doors, and or lock all 4 doors manually and that works fine. So my issue is the security light and key fob not locking or unlocking the doors. I know the fob works as the trunk release button opens the trunk. When I click the lock/unlock button with my head at the base of the windshield I "think" I hear a very dim sound like it's trying to communicate. So the only issue is the door/lock unlock with the fob and the security light. Originally I thought it maybe door lock actuators, but I was told by a GM tech, that since none of the doors lock/unlock it's highly doubtful that it's the actuators.. He suggested trying to relearn the security system and fob.. I've searched all over the internet with no success.. Everything I find is about cars that will not start. Again, I don't have that issue. Any suggestions on how to relearn the key fob and hopefully activating it so the doors lock/unlock and the light goes out..
Thanks, Jake