This happened in my moms old car... Never could figure out the problem, it went to the dealer and a couple different shops my family has always used, no one could figure it out...
Typically there is a way to sync the key fobs with vehicles, I know my brother had to do this with his ford at one point but he had to call ford to figure out how to do it...
I have a road armor, only regret is I didn't get the Lonestar guard on it (Lonestar guard comes up and protects the headlights and grill too)
I'll post some pics later