Has anyone heard of this one? I loaded a mild 40hp tune into my LBZ and afterwards the CEL came on. When I checked my codes, this was the one that came up and it came back everytime I erased it. I was told by GM that it comes on when the ecm loses power while the key is in the on position. Could this happen when loading a tune? I put the stock tune back in and same problem. How do I fix this issue? Or erase this code? Has anyone else encountered it?