Remote Door Unlock Rarely Works

[BDelFav]

My key fob remote door lock/unlock rarely works on my 2002 Tahoe Z71. Even when it does I need to be right next to the vehicle and then it only works sporadically. I walk around the vehicle repeatedly pressing the buttons and usually it will eventually work but it's never in the same location around the vehicle. It seems as though the receiver (wherever it is) is not receiving the signal. I have tried replacing the batteries in the remotes and even bought new remotes but no change in functionality. Any suggestions?

 

[retiredsparky]

Does your car battery seem to have enough power to crank the engine at a normal speed? If the car battery were weak, that could be a cause. I don't know where the security module is that receives the signal from your remotes, but if you could find it, measure operating voltage at it's input. The key fobs must be ok, since you tried new ones. Did you have any trouble programming the new ones?