We own a 2002 Impala and it's been giving us problems for about a week now. When we tried to start it it made a strange sound but it started. Then tonight, it wouldn't even try to turn over, it refuses to start. So we bought a new battery and it still won't start. Been researching a lot of things but so far everything we've found has to do with the remote start/"factory anti-theft system" and our car doesn't have either. There is no alarm or anything like that on it. There is no chip in the key, there's no remote unlock, manual only. Checked the fuses, they were all good. When it actually would start within the past week, the clock would reset itself to 12:00. I don't think it's the starter, because that wouldn't reset the clock.

What could this be and what would be the cheapest/easiest fix for it?

 

the anti theft system for your car will not have a resister on the key that is a passkey system yours has passlock system. check this link for types of systems. im having a no start issue myself with my 2000 impala. and am stuck too but have a thread running about it if I figure something out i'll let you know.

Key immobilizers and remote starting

 

I think you're thinking too complicated right off the bat, you said it sounded weird and hasn't cranked since?? Have you checked the starter at all?