This isn't on my truck, but on one I was looking at for a friend today. There was P2563 (Turbocharger Boost Control Position Sensor Performance) & P003A (Turbocharger boost control position not learned) stored in the ECM. I found that at idle the vane position would not respond at all, and when I initiated the vane relearn, it did nothing. Hoever, I discovered that above idle, at say 1200 RPM, the vane position would respond properly, and the TC relearn would cycle and come up complete. Pretty much the two things that come to mind are the vanes are caked up with soot causing them to not respond properly, or there's an oil flow problem (such as a spun or partially spun cam bearing). Anyone have any thoughts?