Replace fuse #9 (RT Low Beam) in the underhood fuse block. The DRL circuit design on this car is very odd (to say the least) so you'll just have to trust me. I can find no legit reason they designed it the way they did but blowing fuse 9 produces exactly the strange side-to-side behavior you're experiencing. Makes you wonder what the circuit team was smokin' that day.
For future readers of this thread with the alternative issue (a blown fuse #7 (LT Low Beam)), the left low beam would be out both day & night while using the AUTO switch position.
Last edited by greenman; 04-26-2012 at 01:18 AM.