I have a 2007 SS non turbo sedan that been having this problems the past month with my drivers door. It wont unlock with the key fob or driver/passager door switchs. It jiggles like it want to, but doesnt fully unlock. I can manually unlock the door by puller up the switch on the door and the door opens fine.

 

Might just need lubricated. Pull the interior door panel off and get some white lithium grease and spray on the mechanism while you lock and unlock it. If that doesn't work, the actuator is probably bad

 

You need a door lock actuator.

 

^both these guys are right. And if u let it go too long your door could get stuck on lock like mine did. I had to crawl in and out the passenger side for a week.