Nancy, There could be a number of things as to why your key fob is not working, the first step I would take would be to change the key fob battery. In most cases this will fix the problem. If this a new key fob, you will need to get the programmed for your vehicle. Depending on the year your vehicle was made, you can do this on your own. If this is a newer car 2012 and up you will likely need a locksmith or dealership to get the key programmed. You can find a local locksmith (much cheaper than the dealership) on keylessentryremotefob.com