So opened my car, drove somewhere, locked it and fob wouldn't open car. Light was still showing on fob. Key had not got wet or anything in between and had only been about 5 minutes since I used fob to lock car/arm alarm. Had to go home to get spare key, which worked. Any idea what might have happened to this fob? I have also tried a new battery in the fob but that hasn't done anything. Thanks in advance.