Was your truck affected by the TSB in your link TB-18-016-09?
If so, and if it did not have the corrective actions performed, sounds like that could be your issue.
If not, it still sounds like the SRV itself crapped out. I kinda doubt its the PCM itself as I would suspect that both banks would be effected, but I do not know the wiring on that.
Looks like its about a $200 part plus labor...no idea on that but you could find out if you wanted to subscribe to alldata...$25/year is well worth it for my truck.
Not familiar with the repair procedure but I'm struggling to understand why this thing exists at all...if its so beneficial why didn't they design the intake system to use this air path all the time?