Dtc Code P0641

Ok, being a 2012, take it to the dealer! this will be under some form of warrinty. 

This is why>>> when this code is indicated, the "ECM" has dectected, the "5 volt Reference circuit voltage is either Higher or Lower than expected" further more, this happens to have 2 internal  5-volt reference buses, called "5-volt reference 1, AND "5-volt reference bus 2" each of these "buses" has more than one item on that ciruit. Therefore, all items on that curuit, would have some issue. In short, if you dont have a lot more codes showing up, and maybe this is "All of the Sudden", this is telling me, that you have a faulty ECM. 

Dont feel bad, GM does have these issues. As a customer, new or used, you will never know if you vehicle was made on a Friday, or Monday, or even the last day before a big break, like a holiday, or some other shut down..... " Yep, it ill fit, hit it with a hammer! Ya did? Get a bigger hammer!....