Engine Problem

[tower1]

Has anyone had there check engine light come on and code ( "p0045" turbo supercharger open circut) came on. I reset cleared the code with my code reader and yesterday it came on again. While going down the road at 70 with an enclosed bumper pull trailer. It will down shift like it lost power. If anyone here has driven big truck you know the sound that an electric fan make when it engages. It sounds like that as well as at the same time it sounds like the turbowaste gate stays open and doesnt give the engine boost. I know the turbo is still spinning because I can hear the whistle and because im foggin. But in about 3-4 mins it sounds like the waste gate closes and then the truck shifts back into high gear and all is good. Other then the pretty little engine light on the dash that lets me know my engine is still running. Anyone have any idea's

ps. I bought the truck with 12,500 miles 2 months ago the guy that owned it before me kept it in his garage and drove it in the summer.

[Hook'em_Horns!]

Your LLY doesn't have a wastegate, are any unusually higher temps involved?

[tower1]

The temps seem to be fine...

[4141SHAWN]

Hows The Oil Pressure?

[tower1]

The oil pressure stays at 60psi going down the road and drops to 40 at idle.

[4141SHAWN]

alot of times that code leads to a turbocharger learn procedure.