I was just looking for information about this as I ran a diagnostic check on my rMBP and noticed the same code pop up. Called Apple and they told me to take it to a certified Apple Repair Store (since I do not have any Apple Stores within the area) so I will be doing that tomorrow. She specialist over the phone had me do PRAM reset and another reset and the code still came up.
Did you ever end up taking yours to the store?