08 Lacrosse Super Security System not programmed
 

Hey all, New to the group and have a question about the 08 Lacrosse Super I just bought... Apon looking over the car at the lot I put a scanner on it just to check even though the mechanic tried telling me he scanned it and there was nothing that came up... I've been through this too many times and I know they unhook the battery and you won't know if there is an issue until you get 40 miles or so down the road and of course there was a P0521 code for a Oil sensor Switch but that's besides the point, After running the car and test driving it everything seemed good but when I went to park it I noticed on the dash it said security system not programmed! I asked him if he knew what the deal was and he said the thinks the previous owner had the key replaced and there's no key fob for the car. does anyone here know what I need to do to get it programmed? As far as I know these Lacrosse Super Editions all came with remote start which id like to be able to use and also be able to use the fob to unlock, Lock and open the trunk. But that might not be even related to the problem. I've programmed a few key fobs on my past cars and I know that the key had to be the original to be able to make additional keys but they were the type that had a fob and key combined. Any help would be appreciated. I know the easiest answer would be to take it to the dealer or have a locksmith come and handle it but it it's something I can take care of myself id prefer to do that instead. Thanks in advance.