When just that one half of the bulb doesn't work, and the same part is for the signal and brake light, it's usually a problem in the turn signals switch. The brake light circuit goes through the signal switch so that circuit can be turned off, and the bulb is activated only by the signal flasher when you turn on the right signals.
The signal switch, (also called the multifunction switch), on your car is not a very high-failure item so I would be comfortable sending you to a salvage yard for a used one. If you have a pick-your-own-parts yard nearby, you can remove the used one first to see what's involved. They typically come out after removing some plastic covers and only two or three screws.
If you would rather do some testing first to verify the switch is the likely suspect, you'll need a test light or digital voltmeter. If you can't figure out which wire color to test for voltage, I do have the DVD for your car but my DVD player won't open so I'll have to hook up a different computer.
You can either start at the rear socket and work your way forward to see if there's a break in the wire, or you can start at the signal switch, then, if you do have voltage there, you can work your way backward toward the bulb to find where you lose voltage.
Monday, April 2nd, 2012 AT 8:28 PM